Not only yuzu but also hesperidin inhibited caspase-3 activity, myeloperoxidase expression, α-smooth muscle actin expression, and matrix metalloproteinase-2 activity in a permanent LAD occlusion rat model. To our knowledge, our findings provide the first evidence that yuzu and hesperidin prevent MI-induced ventricular dysfunction and structural remodeling of myocardium.Left ventricular (LV) remodeling, which includes ventricular dilatation and increased interstitial fibrosis after myocardial infarction (MI), is the critical process underlying the progression to heart failure. Therefore, a novel approach for preventing LV remodeling after MI is highly desirable. Yuzu is a citrus plant originating in East Asia, and has a number of cardioprotective properties such as hesperidin. However, no study has proved whether yuzu can prevent LV remodeling. The aim of this study was to determine the effects of yuzu on heart failure (HF) and its potential impact on the LV remodeling process after MI. Our  LV remodeling is pathologic changes in the architecture of the LV that occur due to various cardiovascular diseases (CVDs) including MI and hypertension LV remodeling after MI is a key contributor to HF, which is one of the most common causes of cardiovascular morbidity and mortality worldwide Citrus junos Sieb ex Tanaka), one of the natural products receiving attention for their health benefits, is a citrus fruit native to northeast Asia, including Korea, China, and Japan. It has been used in traditional medicine in northeast Asia, and it is known to improve blood circulation and prevent colds in vivo and in vitroYuzu (in vivo study. Hesperidin and polyethylene glycol (PEG) were purchased from Sigma Chemical Co. . Because hesperidin is water-insoluble, it was dissolved in 70% PEG which is a widely used solvent for water-insoluble compounds in in vivo study Ethanolic extract of yuzu were obtained from Konkuk University . Briefly, Yuzu fruits minced were extracted with ethanol and lyophilized to remove solvent. Yuzu extract was dissolved in saline (0.9% NaCl) for the 2 inhalation for heart isolation. LV was used for staining experiments. Infarct and peri-infarct zone of left ventricle were used for gelatin zymography and western blot analysis. Peri-infarct zone was defined as the area within 2 mm of the visible edge of infarction All experimental procedures conformed to the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health , and the Committee on Animal Research at Ajou Medical Center, Ajou University , approved the study. Male Sprague-Dawley rats  were anaesthetized with an intraperitoneal injection of ketamine (100 mg/kg) and xylazine (10 mg/kg) before surgery. The body temperature of the rats was maintained at 37±0.5°C during surgery by using a thermostatically controlled warming plate as described previously The rats were randomly distributed into experimental pre-treatment groups with similar body weights. Yuzu , hesperidin , vehicle  or sham  was administered by oral gavage once daily beginning 7 days before LAD occlusion and continuously administered until the time of the terminal study, using oral gavage around 10∶00 A.M. every morning  and xylazine (10 mg/kg) and were examined with non-invasive echocardiography . Ventricular remodeling in the vehicle-, yuzu-, or hesperidin-treated groups was assessed weekly with serial echocardiography (beginning 0 week prior to LAD occlusion until 4 weeks after LAD occlusion). Cardiac ventricular dimensions were measured on M-mode images . And the average of 5 consecutive cardiac cycles of each animal is reported.LV tissue was fixed with 4% paraformaldehyde for 24 hours, dehydrated with increasing concentrations of ethanol, and then embedded in paraffin. LV sections (5 µm) were stained with hematoxylin and eosin  or Masson trichrome (polysciences) as previously described Immunostaining was performed using a streptavidin–biotin-immunoperoxidase complex method with 5 µm thick sections, which had been deparaffinized and heated in 0.01 M citrate buffer solution (pH ¼6.0) for 15 min for antigen retrieval. Rabbit polyclonal antibody against, myeloperoxidase (MPO), or cardiac tronponin I (cTnI) purchased from Abcam  was used. The slides were examined using a light microscope  and was evaluated with reference to the optical density of the stain by using a computer-assisted image analysis system, ImageJ1.45F .2. After centrifugation, the supernatants were harvested and 25 µg of protein was mixed with Tris-glycine sodium dodecyl sulfate (SDS) sample buffer. The samples were run on a Novex 10% Zymogram Gelatin Gel, followed by incubation with Zymogram Renaturing Buffer and subsequent incubation with Zymogram Developing Buffer. After an overnight reaction, the gel was stained with Simply Blue Safe Stain (Invitrogen).Gelatin zymography was performed utilizing the Novex In-gel Zymography System , according to the manufacturer’s instructions. Heart tissues were homogenized in 50 mM Tris-HCl (pH 7.5) containing 150 mM NaCl and 5 mM CaCl3VO4, 1 mmol/L PMSF, 10 µg/mL aprotinin, and 10 µmol/L leupeptin. Homogenates were centrifuged at 14, 681 g for 15 min and the supernatants were collected as previously described Heart tissues were homogenized in a buffer containing 50 mmol/L Tris-HCl pH 7.4, 1% NP-40, 150 mmol/L NaCl, 0.25% Na-deoxycholate, 2 mmol/L EDTA, 1 mmol/L NaF, 1 mmol/L NaIn situ labeling of fragmented DNA was performed using the Apop Taq Plus Kit . Briefly, nucleosome-sized DNA fragments were labeled with digoxigenin nucleotide and reacted with peroxidase-conjugated anti-digoxigenin antibody and 3, 3′-diaminobenzidine as previously described All data are expressed as means ± SDs. The results were analyzed using 2-way ANOVA and the differences between groups were compared by using the Student’s t-test. A p value of <0.05 was considered statistically significant. All experiments were repeated at least 4 times.In this study, we evaluated the effects of yuzu and hesperidin on LV remodeling in a rat model of permanent LAD occlusion. The vehicle-treated group showed a significantly greater increase in end-diastolic and end-systolic dimensions (LVIDd & LVIDs) compared to sham group (in vivo findings have pathological relevance, we evaluated the effects of yuzu and hesperidin on cardiac fibrosis in a rat MI model of permanent LAD occlusion. The rats were treated with yuzu, hesperidin, or vehicle 1 week before LAD occlusion. As observed upon Masson’s trichrome staining, increased interstitial fibrosis was observed in the rats treated with the vehicle after 4 weeks of LAD occlusion, which was significantly reduced in the group that was pre-treated with yuzu or hesperidin (To determine whether our To histologically confirm that myocardial injury reflected inflammation, we performed H&E staining and MPO immunohistochemical analysis to detect neutrophil activity. H&E staining showed that the strongest inflammatory reactions were observed in the vehicle group. Examination of heart sections of the yuzu- and hesperidin-treated groups showed nearly normal cardiac cells with a well-preserved cytoplasm and prominent nucleolus (We next investigated whether adverse LV remodeling contributed to increased cardiac cell death in the rats with LV remodeling after MI. Apoptosis was evaluated using the TUNEL assay. After 4 weeks of LAD occlusion, the number of TUNEL-positive myocytes was significantly higher in the vehicle groups than in the yuzu- and hesperidin-treated groups (To gain a better understanding of the mechanisms leading to the prevention of LV wall thinning in yuzu- and hesperidin-treated groups, we examined MMP-2 activity and resident cardiomyocytes in the LV myocardium. MMP-2 activity increased in the left ventricles of rats subjected to LAD occlusion, whereas treatment with yuzu significantly reduced MMP-2 activity to levels similar to those observed in sham-operated animals (Herein, we provide the first evidence for the cardioprotective role of the ethanolic extract of yuzu and its major component, hesperidin in rat chronic MI model induced by permanent LAD occlusion, by demonstrating that the ethanolic extract of yuzu and hesperidin prevented heart from MI-induced dysfunction, LV fibrosis, inflammatory reaction and myocyte apoptosis.Chronic MI results in complex architectural alterations such as dilatation of the LV and infarct thinning, which is called LV remodeling, in both infarct and non-infarct region. Patients exhibiting extensive LV remodeling after MI are more likely to experience complications such as HF and myocardial rupture, leading to an elevated risk of mortality After chronic MI, LV fibrosis contributes to adverse structural remodeling, leading to impaired contractile properties of the LV as well as deteriorated electrical conduction system Regarding cardiac structure remodeling process after chronic MI, recent studies have identified the importance of several inflammatory mediators that are released during this process, such as neutrophils and various cytokines, and inflammatory cells are attracted to the myocardial injury site Experimental models and clinical studies have shown that loss of functional cardiomyocytes contributes to structural changes that underlie progressive LV remodeling during chronic MI Cardiomyocyte loss during ischemic damage can be replaced by non-contractile fibrotic cells rather than by new cardiomyocytes LV remodeling after chronic MI remains a major cause of morbidity and mortality worldwide, leading to a dramatical increase of health care costs


To assess the prognostic significance of infarct core tissue characteristics using cardiac magnetic resonance (CMR) imaging in survivors of acute ST-elevation myocardial infarction (STEMI).n = 267). Native T1 was measured in myocardial regions of interest (n = 288). Adverse remodelling was defined as an increase in left ventricular (LV) end-diastolic volume ≥20% at 6 months. All-cause death or first heart failure hospitalization was a pre-specified outcome that was assessed during follow-up (median duration 845 days). One hundred and sixty (56%) patients had a hypo-intense infarct core disclosed by native T1. In multivariable regression, infarct core native T1 was inversely associated with adverse remodelling [odds ratio ] per 10 ms reduction in native T1: 0.91 ; P = 0.061). Thirty (10.4%) of 288 patients died or experienced a heart failure event and 13 of these events occurred post-discharge. Native T1 values (ms) within the hypo-intense infarct core (n = 160 STEMI patients) were inversely associated with the risk of all-cause death or first hospitalization for heart failure post-discharge  including after adjustment for left ventricular ejection fraction, infarct core T2 and myocardial haemorrhage. The prognostic results for microvascular obstruction were similar.We performed an observational prospective single centre cohort study in 300 reperfused STEMI patients  who underwent CMR 2 days and 6 months post-myocardial infarction (Infarct core native T1 represents a novel non-contrast CMR biomarker with potential for infarct characterization and prognostication in STEMI survivors. Confirmatory studies are warranted.NCT02072850. See page 1060 for the editorial comment on this article (doi:10.1093/eurheartj/ehv517)n = 267) post-myocardial infarction and clinical follow-up (median duration 2.5 years). Infarct core pathology revealed by native T1 mapping was feasible [n = 288 (96%) with evaluable data] and had superior prognostic value compared with infarct core T2 and myocardial haemorrhage, and similar prognostic value compared with microvascular obstruction revealed by late gadolinium enhancement CMR. Infarct core native T1 is a novel non-contrast CMR biomarker with potential for infarct characterization and prognostication in STEMI survivors.Contrast-enhanced cardiac magnetic resonance (CMR) imaging is the established approach for imaging infarct pathology in survivors of ST-elevation myocardial infarction (STEMI). The pathophysiological and prognostic importance of infarct pathology disclosed by non-contrast native T1 CMR mapping in acute STEMI patients is unknown. We performed a prospective single centre cohort study in 300 reperfused STEMI patients who underwent CMR 2 days and 6 months  reflect the efficacy of reperfusion therapy and are prognostically important findings in survivors of ST-elevation myocardial infarction (STEMI).Myocardial infarct size7 Native T1 CMR does not involve an intravenous contrast agent. Tissue water content increases as a result of ischaemia and longer T1 times may represent a biomarker of localized myocardial injury.8–16Human tissue has fundamental magnetic properties, including the longitudinal (spin-lattice) relaxation time (native T1 in milliseconds). Native T1 is influenced by water content, binding with macromolecules (water mobility), and cell content.The clinical significance of tissue changes within the infarct core in patients with acute reperfused STEMI has not been directly assessed. We hypothesized that baseline native T1 values would be (i) inversely associated with the severity of MI, including microvascular obstruction, (ii) independently associated with left ventricular (LV) remodelling, and (iii) independently associated with pre-defined health outcomes. Should these hypotheses be confirmed then infarct core native T1 mapping without an intravenous contrast agent might have potential as an alternative biomarker to microvascular obstruction revealed by contrast-enhanced CMR.To investigate these hypotheses, we measured native T1 in myocardial regions of interest in STEMI patients undergoing serial CMR imaging 2 days and 6 months post-MI. We assessed the clinical associates of native T1 within the hypo-intense infarct core and subsequent LV remodelling and examined its association with all-cause death and first hospitalization for heart failure.17 Exclusion criteria represented standard contra-indications to contrast CMR, including a pacemaker and estimated glomerular filtration rate <30 mL/min/1.73 m2. The study was approved by the National Research Ethics Service and all participants provided written informed consent. Acute STEMI management followed contemporary guidelines.18 Aspiration thrombectomy, direct stenting, anti-thrombotic drugs, and other therapies were administered according to clinical judgment  or thrombolysis for acute STEMI due to a history of symptoms consistent with acute myocardial ischaemia and with supporting changes on the electrocardiogram (ECG) (i.e. ST-segment elevation or new left bundle-branch block).judgment . The Cli19 The imaging protocol included cine magnetic resonance imaging with steady-state free precession (SSFP), native T1 mapping,20 T2 mapping,22 T2*-mapping, and delayed-enhancement phase-sensitive inversion-recovery pulse sequences.23 The scan acquisitions were spatially co-registered and also included different slice orientations to enhance diagnostic confidence. Cardiac magnetic resonance was also performed in 50 healthy volunteers of similar age and gender in order to obtain local reference values for myocardial native T1  1.5-Tesla scanner with a 12-element phased array cardiac surface coil.ative T1 . Patientative T1 .20 before contrast administration  1.1 ms, T1 of first experiment 100 ms, TI increment 80 ms, matrix 192 × 124 pixels, spatial resolution 2.2 × 1.8 × 8.0 mm, slice thickness 8 mm, and scan time 17 heartbeats. The prototype pulse sequence did not involve motion correction.Native T1 maps were acquired in three short-axial slices , using an optimized modified look-locker inversion recovery (MOLLI) T1-mapping investigational prototype sequence22 . Typical imaging parameters were: bandwidth ∼814 (8×) Hz/pixel; flip angle 18°; matrix 256 × 115; spatial resolution 2.6 × 1.6 × 10 mm; slice thickness 8 mm.2+-DOTA, Dotarem, Guebert S.A.) using segmented phase-sensitive inversion recovery turbo fast low-angle shot sequence.23 Typical imaging parameters were: matrix = 192 × 256, flip angle = 25°, TE = 3.36 ms, bandwidth = 130 Hz/pixel, echo spacing = 8.7 ms, and trigger pulse = 2. The voxel size was 1.8 × 1.3 × 8 mm3. Inversion times were individually adjusted to optimize nulling of apparently normal myocardium .Early gadolinium enhancement (EGE) imaging was acquired 1, 3, 5, and 7 min post-contrast injection using a TrueFISP readout and fixed inversion time (TI) of 440 ms. Late gadolinium enhancement images covering the entire LV were acquired 10–15 min after IV injection of 0.15 mmol/kg of gadoterate meglumine . The late gadolinium enhancement images were analysed for infarct size and microvascular obstruction by observers (N.A. and I.M.) who were blinded to all of the other data. In healthy volunteers, the absence of late gadolinium enhancement was determined qualitatively by visual assessment.The images were analysed on a Siemens work-station by observers with at least 3 years CMR experience . All of the images were reviewed by experienced CMR cardiologists (C.B. and N.T.). Left ventricular dimensions, volumes, and ejection fraction were quantified using computer-assisted planimetry . The native T1 map analyses were informed by contemporary CMR guidelines.24 Left ventricular contours were delineated with computer-assisted planimetry on the raw T1 image and copied onto the colour-encoded spatially co-registered map. Apical segments were not included because of partial volume effects. Particular care was taken to delineate regions of interest with adequate margins of separation from tissue interfaces prone to partial volume averaging such as between myocardium and blood.25 Each T1 map image was assessed for the presence of artefacts relating to susceptibility effects, or cardio-respiratory motion. Each colour map was evaluated against the original images. When artefacts occurred the affected segments were not included in the analysis.Native T1 mapping is a CMR method providing a parametric colour-encoded anatomical map in which the T1 value is encoded in each pixel22 The hypo-intense infarct core was defined as an area in the centre of the infarct territory having a mean T1 value of at least 2 standard deviations (SDs) below the T1 value of the periphery of the area at risk.22 The assessment of T1 maps and adjudication (present/absent) of a hypo-intense core was performed independently by D.C.In STEMI patients, myocardial T1 values were segmented spatially and regions of interest were defined as (i) remote myocardium, (ii) injured myocardium, and (iii) infarct core. The regions of interest were planimetered to include the entire area of interest with distinct margins of separation from tissue interfaces to avoid partial volume averaging. The remote myocardium region of interest was defined as myocardium 180° from the affected zone with no visible evidence of infarction, oedema, or wall motion abnormalities . The infarct zone region of interest was defined as myocardium with pixel values (T1 or T2) >2 SD from remote myocardium on T2-weighted CMR.26 T1 was measured in each of these segments, and regions of interest were planimetered distinct and separate from blood-pool and tissue interfaces. These segmental values were also averaged to provide one value per subject. Results are presented as average values for segments and slices.In healthy volunteers, the mid-ventricular T1 colour-encoded map was segmented into six equal segments, using the anterior right ventricular-LV insertion point as the reference point.27 Infarct regions with evidence of microvascular obstruction were included within the infarct area and the extent of microvascular LV ventricular mass was also measured. The measurements of infarct size were performed by I.M. and N.A.The presence of acute infarction was established based on abnormalities in cine wall motion, rest first-pass myocardial perfusion, and delayed-enhancement imaging in two imaging planes. In addition, supporting changes on the ECG and coronary angiogram were also required. Acute infarction was considered present only if late gadolinium enhancement was confirmed on both the axial and long-axis acquisitions. The myocardial mass of late gadolinium (grams) was quantified using computer-assisted planimetry and the territory of infarction was delineated using a signal-intensity threshold of >5 SDs above a remote reference region and expressed as a percentage of total LV mass.Microvascular obstruction was defined as a dark zone on EGE imaging 1, 3, 5, and 7 min post-contrast injection that remained present within an area of LGE at 15 min. Identification of microvascular obstruction was performed independently by I.M. and N.A.28–30 In order to assess the area-at-risk, the epi- and endocardial contours on the last corresponding T2-weighted raw image with an echo time of 55 ms were planimetered.21 Contours were then copied to the computed T2 map and corrected when necessary by consulting the SSFP cine images.Area-at-risk was defined as LV myocardium with pixel values (T2) >2 SDs from remote myocardium.31 The myocardial salvage index was calculated by dividing the myocardial salvage area by the initial area at risk.Myocardial salvage was calculated by subtraction of per cent infarct size from per cent area at risk.3Adverse remodelling was pre-defined as an increase in LV end-diastolic volume ≥20% at 6 months from baseline.32–35 was considered to confirm the presence of myocardial haemorrhage.On the T2* maps, a region of reduced signal intensity within the infarcted area, with a T2* value of <20 ms17 was expressed as complete (≥70%), incomplete (30% to <70%), or none (≤30%).A 12-lead ECG was obtained before coronary reperfusion and 60 min afterwards. The extent of ST-segment resolution on the ECG assessed 60 min after reperfusion compared with the baseline ECG before reperfusionThe acquisition of the ECGs and blood samples for biochemical and hematologic analyses are described in We pre-specified adverse health outcomes that are pathophysiologically linked with STEMI. The primary composite outcome was (i) all-cause death or first heart failure hospitalization . Other hFigure 2). Each serious adverse event (SAE) was reviewed by a cardiologist who was independent of the research team and blinded to all of the clinical and CMR data. The SAEs were defined according to standard guidelines37  for continuous data with normal distribution, otherwise the non-parametric Wilcoxon rank sum test or Kruskal–Wallis test. Differences in categorical variables between groups were assessed using a χ2 test or Fisher's test, as appropriate. Correlation analyses were Pearson or Spearman tests, as indicated. Random effects models were used to compute inter- and intra-rater reliability measures [intra-class correlation coefficient (ICC)] for the reliability of infarct core native T1 values measured independently by 2 observers in 12 randomly selected patients from the cohort.Categorical variables are expressed as number and percentage of patients. Most continuous variables followed a normal distribution and are therefore presented as means together with SD. Those variables that did not follow a normal distribution are presented as medians with interquartile range. Differences in continuous variables between groups were assessed by the Student's Univariable and multivariable linear regression methods to identify associates of T1 values for (i) remote myocardium, (ii) injured myocardium within the area at risk, (iii) infarct core in all patients, and (iv) in patients without late microvascular obstruction are described in et al.38Receiver-operating curve (ROC), Kaplan–Meier, and Cox proportional hazards methods were used to identify potential clinical predictors of all-cause death/heart failure events and MACE, including patient characteristics, CMR findings, and native T1. The net reclassification improvement (NRI) was calculated as described by Pencina P-values are two sided. P-value of<0.05 should be interpreted exploratively. Statistical analyses were performed using R version 2.15.1 or SAS v 9.3, or higher versions of these programs.All Figure 2). Two hundred and ninety-two STEMI patients had a T1-map acquisition and 288 (99%) had evaluable T1 data . Cardiac magnetic resonance follow-up at 6 months was achieved in 267 (93%) of the patients and the reasons for non-attendance are summarized in Figure 2. Information on vital status and SAEs were available in all (100%) of the 288 participants.Of 343 STEMI patients referred for emergency reperfusion therapy, 300 underwent serial CMR at 1.5 T 2.2 ± 1.9 days and 6 months after hospital admission , grouped by thirds of native T1]. The C-reactive protein and leucocyte results are described in Table 2 and case examples are shown in Figure 2. At baseline, the mean (SD) myocardial infarct size was 18 (14) % of LV mass. The average infarct core native T1 (997 (57)) was higher than native T1 in the remote myocardium 961 (25) ms; P < 0.01] but lower than native T1 in the area at risk (1097 (52) ms; P < 0.01). The ICC for T1 core is described in The CMR findings are summarized in P < 0.04), independent of left ventricular ejection fraction (LVEF), LV end-diastolic volume, or infarct size (Table 3).Native T1 in the infarct core was inversely associated with thrombolysis in myocardial infarction (TIMI) coronary flow grades at the end of emergency PCI, Killip class and neutrophil count at initial presentation .Infarct core native T1 (ms) was univariably associated with infarct core T2 (ms)  STEMI patients with a hypo-intense native T1 infarct core also had microvascular obstruction. In contrast, only 6.3% of those without hypo-intense infarct core had late microvascular obstruction. The negative- and positive predictive values of native T1 infarct core for T2 infarct core, myocardial haemorrhage, EGE, and microvascular obstruction are summarized in Table 2). Adverse remodelling occurred in 30 (12%) patients and 23 (77%) of these patients had a hypo-intense native T1 core at baseline. Infarct core native T1 (ms) was not associated with change in LV end-diastolic volume at follow-up (P = 0.531). In multivariable regression, native T1  within the hypo-intense core was inversely associated with adverse remodelling (Table 4).At 6 months, LV end-diastolic volume increased on average (SD) by 5 (25) ml in 262 patients with evaluable data (n = 66) vs. Q1–Q3 (n = 196) (n = 26 missing); odds ratio 0.994 ; P = 0.048).In a sensitivity analysis, the occurrence of a hypo-intense core within the infarct zone on T1 mapping was associated with the odds ratio for being in the top quarter of an increase in LV end-diastolic volume at 6 months  was not associated with LV volumes at follow-up, and there was no evidence of non-linearity between infarct core T1 (ms) and LV outcomes.The relationships for infarct core native T1 (binary and continuous), T2 core (binary and continuous), microvascular obstruction , and myocardial haemorrhage for LV outcomes, including LV end-diastolic volume and LV ejection fraction, are shown in Infarct core native T1 early post-MI was associated with the concentration of NT-proBNP, a biochemical measure of LV remodelling, at 6 months independent of LV end-diastolic volume at baseline .n = 20) or defibrillator implantation n = 2). Thirteen (4.5%) patients died or experienced a first heart failure hospitalization post-discharge, and 8 (61.5%) of these patients had a hypo-intense infarct core at baseline.All 288 patients had long-term follow-up data completed. Thirty (10.4%) patients died or experienced a heart failure event. These events included 5 cardiovascular deaths, 3 non-cardiovascular deaths, and 22 episodes of heart failure (Killip Class 3 or 4 heart failure (n = 160 STEMI patients) were inversely associated with the risk of all-cause death or first hospitalization for heart failure post-discharge  0.617, 0.863; P < 0.001) including after adjustment for LVEF at baseline, infarct core T2 (10 ms difference), and myocardial haemorrhage . Infarct core T1 retained its prognostic significance over and above infarct core T2 and myocardial haemorrhage . The net reclassification index for the inclusion of infarct core native T1 (10 ms) in a multivariable prognostic model for all-cause death or heart failure post-discharge was 1.129 ; P < 0.001) (Table 6). Using ROC analysis, the C-index for infarct core native T1 for all-cause death or heart failure was 0.806. The C-indexes for the prognostic model without and with infarct core native T1 (ms) were 0.715 and 0.931, respectively.Native T1 values (ms) within the hypo-intense infarct core (P < 0.001) and the amount of microvascular obstruction (% LV mass) (P < 0.001) were associated with all-cause death or first heart failure hospitalisation after discharge. In a post-hoc analysis stimulated by peer review, the odds ratio for infarct core T1 (10 ms) at baseline for the occurrence of all-cause death, heart failure hospitalisation or adverse LV remodelling was 0.92 , P = 0.0312. The inverse relationships between infarct core native T1 (ms) and LV surrogate and adverse health outcomes were reasonably linear, and there was no cut-off value for infarct core T1 (ms) for these outcomes.In univariate Cox models for infarct core native T1 (ms), native T1 core (binary), T2 core (ms), T2 core (binary), myocardial haemorrhage and the presence (binary) and amount of microvascular obstruction (% LV mass), only infarct core native T1 (ms) (Table 6), implying T1 core is more closely linked with infarct pathology; (v) compared with microvascular obstruction revealed by contrast-enhanced CMR, a hypo-intense infarct core revealed by T1 mapping had similar prognostic significance for LV outcomes at 6 months and for post-discharge cardiac events including all-cause mortality and heart failure hospitalization in the longer term (Tables 5 and 6). Finally, our paper adds to the emerging literature on the prognostic value of quantitative native T1 CMR39 and reaffirms the prognostic importance of MVO post-STEMI.3The main findings of our study are (i) native T1 mapping revealed without an intravenous contrast agent resulted in evaluable scans in 96% of STEMI survivors 2 days post-MI; (ii) acute culprit coronary artery blood flow and circulating measures of systemic inflammation at the time of the hospital admission were multivariable associates of native T1 within the hypo-intense infarct core revealed by T1 mapping 2 days later; (iii) native T1 values (ms) within the infarct core were clinically meaningful since they were independently associated with adverse remodelling, NT-proBNP concentrations at 6 months, and all-cause death or heart failure hospitalization post-discharge during longer term follow-up; (iv) compared with infarct core T2 or myocardial haemorrhage revealed by T2* mapping, infarct core T1 was more consistently associated with LV surrogate outcomes and all-cause death or heart failure hospitalization  and microvascular obstruction (50%) as revealed by contrast-enhanced CMR. Although both a native T1 core and microvascular obstruction are depicted as a hypo-intense core within the hyperintense infarct zone , the physics of the CMR techniques is entirely different. A hypo-intense infarct core depicted by non-contrast native T1 mapping is due to local destruction of the T1 magnetization signal. On the other hand, microvascular obstruction  is due to a failure of gadolinium contrast to penetrate within the infarct core. Both CMR methods are T1-weighted but contrast kinetics are not relevant for native T1 mapping since intravenous contrast is not administered. Accordingly, T1 mapping avoids the theoretical risks and actual restrictions associated with contrast-enhanced CMR. Furthermore, acquisition of the native T1 map does not prolong the CMR scan, in contrast to late gadolinium enhancement imaging for microvascular obstruction which is typically imaged 10–15 min after dosing.19We also compared infarct core pathology delineated by native T1 mapping with microvascular obstruction, which is an established prognostic CMR biomarker post-MI.45 and in our study, both infarct core native T1 and microvascular obstruction were independently associated with circulating biomarkers of acute systemic inflammation. The occurrence of an infarct core disclosed by native T1 mapping, and the nature of the core , was associated with the initial severity of MI (i.e. Killip heart failure class), systemic inflammation (i.e. leucocyte counts), and LV remodelling and health outcomes in the longer term. We think that the prognostic significance of native T1 values within the hypo-intense core are a distinctive attribute compared with microvascular obstruction since signal-intensity values within microvascular obstruction are not clinically meaningful beyond binary categorization (i.e. present/absent).Culprit artery coronary flow at the end of emergency PCI reflects the efficacy of coronary reperfusion, and reduced coronary flow initially independently predicted native T1 relaxation time within infarct core as assessed by CMR 2 days later. Similar associations also exist for microvascular obstruction,We performed a single centre natural-history study involving near-consecutive STEMI admissions. The STEMI patients in our natural-history study were recruited 24/7 therefore flow cytometry and routine NT-proBNP testing in all participants was not pragmatically possible.42 Despite this, the MOLLI method has high precision reproducibility. Our T1 measurements are in good agreement with in vivo data published in the literature, including previous measurements using the ShMOLLI sequence.43T1 assessment is sensitive to motion artefacts and imperfect breath holding, which and may reduce image quality. A shortened version of this sequence (ShMOLLI) involving only nine heart beats has been developed. This method shortens breath hold time and may help to account for these limitations.Tables 4 and 6); however, the associations between infarct core native T1 and a range of surrogate and clinical outcomes including adverse remodelling revealed by CMR, NT-proBNP, and the primary health outcome , supports the adverse prognostic importance of infarct core native T1. Our study does not permit inference on causality, and other interpretations of our data are possible and further studies are warranted.The limited number of adverse events constrained the number of variables that could be included in the multivariable models , the National Health Service, and the Chief Scientist Office. Professor Berry was supported by a Senior Fellowship from the Scottish Funding Council. Dr Welsh is supported by BHF Fellowship FS/12/62/29889. Funding to pay the Open Access publication charges for this article was provided by the University of Glasgow.Conflict of interest: This project was supported by research collaboration with Siemens Healthcare.Supplementary DataClick here for additional data file.


Right ventricular (RV) pressure overload results in interventricular septal displacement (IVSD) towards left ventricle in patients with pulmonary arterial hypertension (PAH). There is however scarce data on the duration of IVSD during cardiac cycle as expressed by curvature duration index (CDi) and its potential role in the evaluation of PAH patients. The aim of our study is to reveal the potential value of CDi as a marker of RV function and pressure overload.All patients underwent cardiac magnetic resonance . A routine set of LV and RV short-axis cines of 6 mm slice thickness, were acquired from base to apex using a breath-hold retrospective ECG-gated balanced steady state free precession (SSFP) sequence. CDi , left ventricular eccentricity index in end-systole (LVSei) and end-diastole (LVDei), left ventricular end-systolic (LVESarea) and end-diastolic area (LVEDarea), RV end-systolic (RVESarea) and end diastolic area (RVEDarea) were defined in the short-axis view in the level of papillary muscles. Interventricular septal curvature ratio (CR) was defined in the same level, at end-systole. The right ventricular wall thickness (RVWT) was assessed in the anterior segment of RV. Tricuspid annular plane systolic excursion (CMR-TAPSE) was defined in the 4-chamber view. Right ventricular ejection fraction (RVEF) and RV end-systolic volume (RVESV) and end-diastolic volume (RVEDV) were obtained with the use of serial short axis cine-MRI views from base to the apex, according to Simpson's rule.Our study included 41 consecutive patients  with precapillary pulmonary hypertension . A direct linear correlation between CDi and CMR-TAPSE , CR , LVSei  and LVDei , LVESarea , LVEDarea , RVEF , RVESV , RVESarea , RVEDarea , RVWT  was observed.CDi is a potential non invasive simple marker for the evaluation of RV pressure overload and function in patients with precapillary pulmonary hypertension. Its prognostic significance remains to be established in further studies.Hellenic Cardiological Society.


P = 0.024) and end systolic volume  but not ejection fraction  compared to CMRI. Good correlations of EDV  and EF  between the AS and CMRI were observed. EF measured by the AS and 3DE also correlated significantly . After subjection of pigs to MI, the AS very moderately overestimates LV volumes and shows accurate measurements for EF compared to CMRI. This makes the AS a useful tool to determine cardiac function and dynamic changes in large animal models of cardiac disease.A novel admittance‐based pressure–volume system (AS) has recently been developed and introduced. Thus far, the new technique has been validated predominantly in small animals. In large animals it has only been compared to three‐dimensional echocardiography (3DE) where the AS showed to overestimate left ventricular (LV) volumes. To fully determine the accuracy of this device, we compared the AS with gold standard cardiac magnetic resonance imaging (CMRI) in a porcine model of chronic myocardial infarction (MI). Fourteen pigs were subjected to 90 min closed chest balloon occlusion of the left anterior descending artery. After 8 weeks of follow up, pigs were consecutively subjected to LV volume measurements by the AS, CMRI, and 3DE under general anesthesia. The AS overestimated end diastolic volume (EDV; +20.9 ± 30.6 mL,  Is the novel admittance‐based pressure–volume loop system reliable for the assessment of left ventricular volumes compared to gold standard cardiac magnetic resonance imaging in a porcine model of myocardial infarction? In the postinfarction remodeled heart, admittance‐based pressure–volume loop measurements accurately measure ejection fraction and very moderately overestimate end diastolic and end systolic volumes compared to gold standard cardiac magnetic resonance imaging, making it a very useful technique for cardiac function assessment in experimental studies. Cardiac function is a main endpoint in efficacy testing of novel therapeutics in clinical and translational cardiovascular research  differs from the classical conductance system in several ways. First, the new method does not assume a constant contribution of parallel conductance during the cardiac cycle . Pigs (body weight 79.1 ± 5.9 kg) were subjected to myocardial infarction followed by invasive PV measurements, CMRI and 3DE at 8‐weeks follow‐up. Before any procedural intervention, animals were housed in pairs. Because of health concerns, animals were housed individually after myocardial infarction until the end of the study. Pigs were fed twice a day, water was available ad libitum.−1 h−1 midazolam, 2.5 μg kg−1 h−1 sufentanyl, and 0.1 mg kg−1 h−1 pancuronium and pigs were mechanically ventilated. Preoperatively, animals received a fentanyl patch (25 μg/h). Arterial access was obtained by introduction of an 8F sheath into the carotid artery after surgical exposure. A coronary angiogram of the left coronary tree was acquired using an 8F JL4 guiding catheter . The diameter of the left anterior descending artery (LAD) was measured directly distally to the second diagonal artery. An adequately sized balloon was placed distal from the second diagonal branch and inflated for 90 min. After reperfusion and observation for approximately 2 h, the surgical wound was closed and animals were weaned from anesthesia. Animals were defibrillated in case of ventricular fibrillation (VF).All animals were pretreated with amiodaron for 10 days , clopidogrel for 3 days (75 mg/day), and acetylsalicylic acid for 1 day . All medication was continued until the end of the study. Animals were anesthetized in their cage with an intramuscular injection of 10 mg/kg ketamine, 0.4 mg/kg midazolam, and 0.5 mg/kg atropine. Anesthesia was maintained with intravenous infusion of 0.5 mg kg™ (Transonic SciSense) linked to a multichannel acquisition system (Iworx 404), required for real‐time data acquisition. A baseline scan was performed to determine the end diastolic and end systolic blood conductance required for absolute volume calculations. The external stroke volume (SV) required for volume calibration and analysis was derived from CMRI measurements. Blood resistivity was assumed to be constant in all animals (150 Ω cm). All measurements were performed during apnea. Data were offline analyzed using Iworx analysis software .Admittance‐based PV‐loop measurements were performed as recently described . Animals were placed on the CMRI table in a supine position, under continuous anesthesia. A 32‐channel receiver coil was placed over the chest. ECG‐gated steady‐state free precision cine imaging was obtained in a short‐axis and a two‐chamber long‐axis view . Offline imaging analysis was performed in Qmass MR 7.4 enterprise solutions .3DE was performed with a X3‐1 transducer on an iE33 ultrasound device  directly after CMRI as previously described  in 37°C 0.9% NaCl for 15 min to discriminate infarct tissue from viable myocardium.t‐test. Correlations were tested using Pearson's correlation test. The limits of agreement  of the AS compared to CMRI were determined by Bland–Altman analysis. All statistical analyses were performed in SPSS statistics version 20.0 . A two‐sided P<0.05 was regarded statistically significant in all analyses.All data are expressed as mean ± standard deviation unless stated otherwise. CMRI data and PV measurements were separately analyzed by two different researchers blinded to the outcome of the other technique. End diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) measured by the AS and 3DE were compared with CMRI values using a paired Student's P = NS). Moreover, heart rate correlated significantly  between AS‐ and CMRI‐derived measurements, indicating that both measurements were performed under a steady state.At 8‐week follow‐up after MI, LV volumes were assessed in 14 pigs with both the AS and CMRI  and ESV  were underestimated by 3DE compared to CMRI as expected , with an almost perfect correlation   Figs. . We alsoP = 0.024) and ESV  compared to CMRI   and EF  between the AS and CMRI   Fig. . ImportaMRI Fig.  and a goR = 0.685, P = 0.007) and EF  with infarct size  and EF  compared to infarct size was found, indicating that both systems' measurement reflect the decay in cardiac function after myocardial infarction (Fig. As LV volumes are often measured as surrogates of cardiac function, it is essential to test whether the volume measurements of the various systems reflected the actual extent of myocardial damage. Therefore, infarct size was determined at 8‐week follow‐up. Mean infarct size was 13.8 ± 2.9%. We found a good correlation of CMRI‐based ESV (ize Fig. . For 3DEReal‐time PV loops provide researchers with more detailed information on cardiac function than most imaging modalities (Suga and Sagawa To the best of our knowledge, this is the first study to directly compare the AS with CMRI, the gold standard for in vivo LV volume assessment. Using CMRI as a reference standard in a closed chest porcine model, the AS accurately measures EF with only modest overestimation of EDV and ESV. The AS shows small mean percentage intermethod differences and a better accuracy for EDV, ESV, and EF than 3DE in this study. Furthermore, our study shows that there is a good correlation for EDV and EF between AS and CMRI and a good correlation for EF between AS and 3DE. Both CMRI and 3DE are reflecting the extent of cardiac damage since ESV and EF of the two methods correlate well with infarct size, even though scar remodeling has already occurred after such an extensive follow‐up period and infarct size analysis has become less representative due to possible scar shrinkage and resorption (Holmes et al. Very recently the performance of the AS in a large animal model has also been investigated by us and others (Kutty et al. Both large animal studies were, however, limited by the use of 3DE as the reference standard. It has recently been shown that EDV and ESV are increasingly underestimated by 3DE in more diseased left ventricles, which is in line with our findings in the present study Fig. A–C Mor‐. The undThe current study has several limitations. First of all, measurements were performed under general anesthesia. Since different levels of anesthesia could influence cardiac performance, anesthesia could be a confounding factor in comparing the AS with CMRI despite a consistent heart rate. Second, during CMRI, arterial pressure was not registered. Although heart rates did not indicate a change in hemodynamic state, theoretically a difference in arterial pressure between data assessment with the different systems could occur, possibly influencing the outcome. In this study CMRI was preceded by measurements with the AS. Ideally this should be the other way round since the more invasive procedure could influence measurements with the less invasive procedure. Unfortunately, this was proven to be impossible due to logistical difficulties. Nevertheless, measurements with the AS only take up 15–20 min and the surgical intervention to reach the carotid artery is only minor without any substantial blood loss. Swine used in this study had relatively large hearts compared to averagely sized human hearts (Greupner et al. The authors have nothing to declare and gratefully acknowledge Marlijn Jansen, Joyce Visser, Martijn van Nieuwburg, Grace Croft, and Evelyn Velema for their excellent technical support and Joep van Oorschot for acquiring the MRI images.None declared.


Despite recent advances, myocardial infarction (MI) remains the leading cause of death worldwide. Pre-clinical animal models that closely mimic human MI are pivotal for a quick translation of research and swine have similarities in anatomy and physiology. Here, we compared coronary surgical ligation versus coil embolization MI models in swine.Fifteen animals were randomly distributed to undergo surgical ligation (n = 7) or coil embolization (n = 8). We evaluated infarct size, scar fibrosis, inflammation, myocardial vascularization, and cardiac function by magnetic resonance imaging (MRI).Thirty-five days after MI, there were no differences between the models in infarct size (P = 0.53), left ventricular (LV) ejection fraction (P = 0.19), LV end systolic volume (P = 0.22), LV end diastolic volume (P = 0.84), and cardiac output (P = 0.89). Histologically, cardiac scars did not differ and the collagen content, collagen type I (I), collagen type III (III), and the I/III ratio were similar in both groups. Inflammation was assessed using specific anti-CD3 and anti-CD25 antibodies. There was similar activation of inflammation throughout the heart after coil embolization (P = 0.78); while, there were more activated lymphocytes in the infarcted myocardium in the surgical occlusion model (P = 0.02). Less myocardial vascularization in the infarction areas compared with the border and remote zones only in coil embolization animals was observed .Our results support that surgical occlusion and coil embolization MI models generate similar infarct size, cardiac function impairment, and myocardial fibrosis; although, inflammation and myocardial vascularization levels were closer to those found in humans when coil embolization was performed. Myocardial infarction (MI) is the leading cause of morbidity, mortality, and disability in the worldwide and remains one of the greatest challenges in biomedical research . CurrentNumerous animal models evaluate the pathophysiological mechanisms of ventricular remodeling and MI development and progression ,5. BriefThe presented work aims to compare infarct size, histological traits and cardiac functional changes following surgical ligation or coil deployment. All interventions were performed in the first marginal branch of the circumflex coronary artery in swine and the follow-up period was 35 days.Fifteen Landrace × Large White female pigs (20–30 kg) were randomly distributed into surgical coronary ligation (n = 7) and coronary coil deployment (n = 8) groups. All animals underwent MI induction in the first marginal branch of the circumflex coronary artery and were sacrificed after 35 days of follow-up. This study was approved by the local Animal Experimentation Unit Ethical Committee and complies with all guidelines concerning the use of animals in research and teaching as defined by the Guide for the Care and Use of Laboratory Animals .Pigs were premedicated as previously described . In brieMI was induced in 7 animals after coronary surgical ligation of the first marginal branch of the circumflex coronary artery Figure A-B as prEight animals underwent a coronary coil embolization in the first marginal branch of the circumflex coronary artery Figure C-D as prCardiac function was evaluated by magnetic resonance imaging (MRI) performed at 1.5 T  using a phased-array cardiac coil ,11. All After premedication, pigs were sacrificed with a potassium chloride IV injection. LV infarct size was blindly measured in digitally photographed transverse heart sections from 1 cm distally to the coronary ligation or coil localization. Additionally, in order to confirm a correlation of MRI findings with gross pathology findings, LV infarct size was also analysed in gadolinium enhancement MRI images. Image-Pro Plus software  was used for quantitative morphometric measurements.After sacrifice, hearts were excised and samples from the infarct core and remote myocardium were snap frozen. After 10% buffered formalin fixation, 5 μm tissue sections were stained using Masson’s and Gallego’s trichrome procedures for histological examination. In addition, Picrosirius red staining was performed to analyse myocardial fibrosis, as previously described . The colIn MI sections, inflammation was assessed by measuring the total anti-CD3 antibody positive lymphocytes, those labelled with anti-CD25 antibody, and the CD25/CD3 ratio. Briefly, sections were incubated with primary antibodies against CD3  and CD25  and with conjugated secondary antibodies using donkey anti-rat DyLight 488  and donkey anti-mouse Cy3 , respectively. Vessel density in infarct, border, and remote zones was double-blindly assessed by Isolectin-B4 staining , Alexa Fluor 488-conjugated Streptavidin . Images were captured with a Leica TCS SP5 microscope (20x) and results were expressed as a percentage of the vessel area per field [Data are presented as the mean ± SD. All analyses were performed with SPSS statistic software . Differences in morphometric and histological data between the surgical ligation and coil deployment groups were analysed using Student's t-test and cardiac function evolution was compared using ANOVA with the Greenhouse-Geisser correction. Statistical significance was achieved when P < 0.05.None of the animals died during MI induction or follow-up and were sacrificed at the pre-defined time course .Morphometric analysis from digitally photographed transverse heart sections revealed that LV infarct sizes Figure E-H were Baseline cardiac function was similar in both groups; in the surgical ligation versus coil embolization group with regards to LVEF , LVESV , and LVEDV . At sacrifice, ventricular function measurements were: LVEF , LVESV , and LVEDV . Although the measured baseline CO values were different between surgical and coil occlusion animals , they did not differ at sacrifice  , infarct , and border  zones were detected. Nevertheless, coil deployment animals showed significant differences in the vascularized areas when comparing the infarct zone with remote (P = 0.014) and border (P = 0.004) myocardium. All zones appeared similar in the surgical ligation group animals   and involve open-chest surgery . MoreoveCardiac MRI has become the gold-standard for assessing ventricular function due to its high reproducibility; in addition, this procedure requires fewer animals to evaluate a hypothesis regarding adverse remodeling data . In the et al. also described a slight mononuclear inflammation in the remote areas of infarcted hearts, finding lymphocytes between healthy muscle fibers. Our findings confirm this presence both in coronary surgical ligation and coil embolization models. In particular, the level of CD3+ cells in the remote myocardium was notably increased after open-chest model although not so activated as in coil embolization model. In addition, lymphocyte activation  was also increased in the infarcted area of coil animals. Thus, lymphocyte infiltration in the whole heart after MI is more evident after coronary surgical ligation, probably due to the open-chest approach, as Li et al. suggested [On the other hand, the inflammatory response after MI is crucial for myocardial healing and repair, diminishing tissue injury and regulating scar formation . The infuggested . Howeveruggested . Hence, Interestingly, the growth of subendocardial collateral vessels after acute coronary occlusion has been described both in pigs  and humaIn summary, our results support that surgical occlusion and coil embolization MI models generate similar infarct size, cardiac function impairment, and myocardial fibrosis in swine. However, both inflammation and myocardial vascularization levels were closer to those found in humans when coil embolization was performed. Therefore we suggest the use of coil embolization in pre-clinical MI research, being a better MI model than surgical coronary ligation, to obtain reliable results and leading to prompt clinical applications.Landrace × Large White prepuberal pigs were used and, thus, results may differ from an adult model. For this purpose, minipigs represent a more regular alternative although they require more complex and expensive handling. Moreover, the ischemic model used in this study produces a limited infarct size, without the induction of malignant ventricular arrhythmias and showing limited effects on ventricular function. In addition, the lack of echocardiographic monitoring prevents the evaluation of ischemic mitral valve regurgitation, frequently observed in lateral LV infarction.MI: Myocardial infarction; ECG: Electrocardiogram; MRI: Magnetic resonance imaging; LV: Left ventricular; LVEF: Left ventricular ejection fraction; LVESV: Left ventricular end systolic volume; LVEDV: Left ventricular end diastolic volume; CO: Cardiac output; CVF: Collagen volume fraction.The authors declare that they have no competing interests.CGM carried out the animal experimental set, participated in its design, performed the statistical analysis, and drafted the manuscript. CPV and IDG helped to carry out the experimental procedures. VC carried out MRI analysis. CSB, SR, ALV and IPG carried out the histological and immunohistochemical analysis and helped in acquisition data. FSM and ABG participated in its design and drafted the manuscript. All authors read and approved the final manuscript.Vascularization analysis by Gallego’s trichrome staining. Representative images showing vascular structures (arrows) in myocardial sections including infarct, border and remote zones after surgical occlusion and coil embolization corroborating Isolectin B4 staining data. Note that Gallego’s trichrome technique clearly distinguishes blood vessels (yellowish green) from collagen (dark blue), muscle fibers (yellow), and nuclei (pink). .Click here for file


Marathon runners (MTH) and patients with mitral regurgitation (MR) exhibit left ventricular (LV) overload, and LV geometric changes in these groups have been reported. In this study, right ventricular (RV) adaptation to chronic volume overload was evaluated in MTH and MR and normal controls together with interventricular septal remodeling and tricuspid annulus (TA) motion.A total of 60 age-matched subjects  underwent conventional cine and tagged cardiac magnetic resonance imaging. Myocardial strain and curvature were computed on the interventricular septum and RV free wall. A dual-propagation technique was applied to construct RV volume-time curves for a single cardiac cycle. Similarly, the TA was tracked throughout the cardiac cycle to create displacement over time curve.p = 0.0061). The peak late diastolic TA velocity in MR was significantly faster than MTH (p = 0.0031) and controls (p = 0.020).Septal curvature was significantly lower in MTH and MR compared to controls. No significant differences in RV free-wall strain or RV ejection fraction were noted among the three groups. However, longitudinal TA excursion was significantly higher in MTH compared to controls (Increased TA kinetics allows for improved RV performance in MTH. Septal remodeling was observed in both MR and MTH, therefore a direct relationship of septal remodeling to TA kinetics in athlete’s heart could not be elucidated in this study. The left ventricle undergoes remodeling in response to sustained changes in left ventricular (LV) pressure or volume load. In previous work, we used cardiac magnetic resonance (CMR) imaging to study LV changes in marathon runners (MTH), where the dilated left ventricle maintains an ellipsoid shape, and in mitral regurgitation (MR), where the dilated left ventricle becomes more spherical . Thus, tThis study includes the same cohort of 60 subjects as previously described , which iConventional cine MRI was acquired on a 1.5-T magnetic resonance scanner  to obtain standard  views using prospective electrocardiographically gated, breath-hold, steady state free-precession technique with following scan parameters: slice thickness = 8 mm, zero interslice gap, field of view = 40 cm × 40 cm, scan matrix = 256 × 128, flip angle = 45°, repetition/echo times = 3.8/1.6 ms. Twenty cardiac phases were reconstructed with 8–10 views per segment.Tagged CMR was acquired with the same slice prescription as the cine acquisition. Grid tags were applied to short-axis views and stripe tagging to long-axis views using the spatial modulation of magnetization encoding method with the following scan parameters: prospective ECG gating, slice thickness = 8 mm, zero interslice gap, field of view = 40 cm × 40 cm, scan matrix = 256 × 128, flip angle = 10°, repetition/echo times = 8.0/4.2 ms, views per segment = 8–10, tag spacing = 7 mm, 20 reconstructed cardiac phases.Right ventricular endocardial contours at end-diastole (ED) Figure  and end-Once the volumes were computed at each time frame, a RV volume-time curve (VTC) was constructed and differentiated with respect to time. Early diastole and late diastole were defined as the first and second halves, respectively, of the diastolic interval. RV peak ejection rate (PER) was defined as the maximum negative time derivative during the systolic interval. RV early peak filling rate (ePFR) and atrial peak filling rate (aPFR) were defined as the maximum derivative during the early and late diastole. RV e/a ratio was computed as RVePFR over RVaPFR.Three-dimensional (3D) IVS geometric parameters were measured from LV endocardial and epicardial contours manually traced on cine images acquired near end-diastole and end-systole as described previously , 7–15. TThree-dimensional (3D) endocardial surface curvatures were computed using standard formulas  at the sThree-dimensional LV strains were measured from tagged images at ES. Tag lines were tracked using a tag extraction technique  and editInterventricular septum geometric and strain parameters at the base and mid-ventricular levels were computed by averaging the LV anteroseptal and inferoseptal segments at each level. At the distal level, septal parameters were measured from the LV apical septal segment.Three-dimensional RV geometric parameters were measured using the techniques described above modified for the right ventricle. The RV lateral wall was divided into eight segments: three at base, three at mid, and two at apical level. 2D RV strains were calculated using harmonic phase (HARP) analysis . 2D RV mOne-way analysis of variance was used to compare groups for continuous and categorical variables as performed for left ventricle analysis among three subject groups. Homogeneity of variance was tested using Levene’s test. Model normality assumption was checked and if it was violated, appropriate data transformation was conducted. Tukey–Kramer procedure was performed to control the pairwise comparisons among the groups jointly in order to avoid erroneous type I error rate inflation.p value <0.05 was considered statistically significant. For repeated measures, a p < 0.01 was considered statistically significant to account for correlations among parameters and locations of measurements (Table Data are presented as mean ± SD. A ts Table . All stap < 0.0001(Table p = 0.044). However, once normalized to RVEDV, it was no longer different among the groups. Although there were differences in the RVePFR and RV e/a ratio between MTH and MR, they did not reach statistical significance.As previously described , all parp ≤ 0.0007 at all levels) and ES , whereas it was decreased at the basal (p = 0.0013) and mid (p = 0.0061) levels in ED and at the distal (p = 0.005) level in ES in MR . However, the local torsion shear angle in MTH was similar to both MR and controls.The IVS radius-thickness ratio in ED was increased at distal level in MR versus controls Table . The IVS p = 0.003 and midp = 0.0061). Consistent with RVVTC, the TA kinetics demonstrated significantly shorter time to peak displacement in MTH compared to controls. No difference in the TA kinetics of MR compared to controls or MTH was noted except that the peak late diastolic TA velocity was much faster than MTH (p = 0.0020) and control (p = 0.031) groups (Table Distinct differences were noted in the TA kinetics of MTH compared to controls and MR Figure ; Table 3Cardiac magnetic resonance is known to yield accurate non-invasive RV volumetric measurements –24. In tInterventricular septum plays a critical role in the force transmission and maintenance of mechanical performance of biventricular function , 26–28. Despite similar RV, EF and RV free-wall strains among the groups, the RVVTC suggests a more optimal systolic and diastolic profile in MTH compared to MR. Consistent with this, parallel changes in the TA kinetics in the three groups were also present. TA kinetics play, an important role in the overall RV systolic and diastolic function –32. The In conclusion, our study described changes in the IVS mechanics and geometry due to physiologic versus pathologic left ventricle enlargement and its impact on RV function. We found that RV myocardial contractility and local curvature were similar in MTH and isolated compensated MR with preserved LVEF. There were subtle changes in septal mechanics in physiologic LV remodeling compared to controls. This combined with the findings of increased TA displacement reached in a shorter period of time in MTH suggests an overall favorable adaptive RV response in the MTH group.WZ generated all the experimental data for validation and comparison, drew one set of contours for the inter-user variability study, and drafted the manuscript. WF developed the dual-contour propagation algorithm. CS helped in the design of the statistic testing. HG drew one set of contours served as the gold standard for validation, helped in the study design, and the revision of the manuscript. PR helped with manual contouring and study revision. SL identified manual contours to achieve consensus for validation and revised the manuscript. LD participated in study coordination. TD participated in the study design, coordination, and manuscript drafting.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.http://www.frontiersin.org/Journal/10.3389/fcvm.2015.00008/abstractThe Supplementary Material for this article can be found online at Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.


Left ventricular hypertrophy and diastolic dysfunction in children and adolescents with essential hypertension tend to be underdiagnosed. The aims of this study were to investigate left ventricular hypertrophy and diastolic dysfunction in the subjects with essential hypertension defined by ambulatory blood pressure monitoring.n = 29) and a group with normal BP index (n = 9). Two-dimensional ultrasound with M-mode imaging and tissue Doppler imaging were performed to measure left ventricular mass index and to assess the left ventricular diastolic dysfunction.A total of 38 Korean subjects aged 9–19 years without secondary causes of hypertension were reviewed. Ambulatory blood pressure monitoring was done in the 38 subjects to diagnose hypertension and gain the information of blood pressure pattern. The subjects were divided into two groups: a group with elevated blood pressure (BP) index (2.7) was significantly higher in the group with elevated BP index than the group with normal BP index, but there were no differences in left ventricular diastolic dysfunction evaluated by E/A ratio and E/E’ ratio. Left ventricular mass index was related only with body mass index, while any of the ambulatory blood pressure monitoring parameters did not predict left ventricular hypertrophy. In terms of diastolic dysfunction in essential hypertension, E/E’ ratio in the subjects with left ventricular hypertrophy was higher than that in the other subjects without left ventricular hypertrophy.Left ventricular mass index(g/mLeft ventricular mass index is significantly correlated with body mass index in children and adolescents with essential hypertension, and the diastolic dysfunction could be in higher risk in subjects with left ventricular hypertrophy. Essential hypertension in children is a major health issue, as its prevalence in children and adolescents has risen in accordance with the rise in childhood obesity. The current prevalence of hypertension in children ranges from approximately 1 to 4.5 % in the USA and will continue to increase. Longitudinal studies have shown that children with hypertension are likely to become hypertensive adults with an elevated cardiovascular risk [Left ventricular hypertrophy (LVH) and diastolic dysfunction is the most documented type of cardiac damage that occurs in children and adolescents with hypertension. However, a recent study showed that only a quarter of adolescents with essential hypertension had been examined with echocardiography . As theyIn this study, the diagnoses of hypertension were made using 24-h ambulatory blood pressure monitors (ABPM). ABPM is a favorable method in treating childhood hypertension to provide diurnal blood pressure (BP) patterns . We inten = 29) and subjects with normal BP index (the control group) (n = 9). The study was approved by the institutional review board (IRB) of the Samsung Medical Center. Informed consent was waived by the IRB.Between 2010 and 2014, a total of 55 Korean subjects aged from 9 to 19 years were enrolled in this retrospective study. Subjects were diagnosed with hypertension at other hospitals and referred to Samsung Medical Center for further evaluation and treatment. Of 55 subjects, 17 subjects with secondary hypertension were excluded on the basis of medical history, clinical exams, and several investigations. The 38 remaining subjects were divided in two groups according to their ABPM results: subjects with elevated BP index  . An appropriate cuff chosen for the patient’s arm size was attached to the non-dominant arm. The ABPM device checked the patient’s BP at intervals of 15 to 30 min in their actual personal life. The patients recorded actual daily activities while they were monitored. The BP index was calculated as mean daytime BP divided by the 95th percentile for gender and height by referring to the normalized reference values from the German Working Group study . The BP 3 − (LVID)3 + 0.06. The left ventricular mass index was calculated by dividing the LVM(g) by the height in meters2.7 to correct the left ventricular mass (LVM) for body size. The left ventricular hypertrophy was defined as left ventricular mass index (LVMI) >51 g/m2.7 [Echocardiographic examinations were performed using Vivid E9 . The same cardiologist performed echocardiography on all subjects to evaluate left ventricular structure and diastolic function. The subjects were in the resting state in the left lateral position. The left ventricular end-diastolic internal dimension (LVIDd), end-diastolic septal thickness (IVSd), and posterior wall thickness (PWTd) were measured at end-diastole by two-dimensional guided M-mode echocardiography. The left ventricular mass was calculated according to the equation LVM(g) = 0.8 {1.04(IVSd + LVIDd + PWTd)}The left ventricular diastolic function was assessed by classic pulsed-wave Doppler technique. The mitral inflow velocities were obtained in the apical four-chamber view. The measurements of early diastolic peak flow velocity (E), E-wave deceleration time (DT), late diastolic peak flow velocity (A), and E/A ratio were determined. In this study, the left ventricular diastolic dysfunction was defined as E/E’ ratio >8 or E/A ratio <1.0.U test and Fisher’s exact test were used.Data were expressed as mean ± SD or proportion (%) of patients. SPSS 21.0 was used for the statistical analysis. For the evaluation of the difference between two independent groups, the nonparametric Mann-Whitney p < 0.05.The Spearman correlation coefficient and logistic regression test were used to predict the left ventricular hypertrophy and diastolic dysfunction. The statistical significance was defined when p < 0.00) and BP load (p < 0.001) than those in the control group. However, there was no statistical difference in night dip between the two groups. Compared to those in the control group, the subjects with hypertension had a significantly higher BMI (p = 0.001). LVMI (g/m2.7) was significantly higher in the essential hypertensive group, but LVH(%) was not higher in the controls. No difference was found in Tei index and LV diastolic function evaluated by E/A ratio and E/E’ ratio between the two groups.The anthropometric characteristics, blood pressure characteristics, and echocardiographic findings of 29 hypertensive subjects and nine controls are described in Table p < 0.001) . The correlation analysis showed that there was a significant quantitative linear relationship between LVMI and BMI  Table . BMI wasp = 0.014) . The risk factor analysis indicated that the ABPM parameters, anthropometric measurements, and LVMI did not predict LV diastolic dysfunction. We investigated the relationship between LVH and LV diastolic function by comparing the hypertensive subjects with LVH with those without LVH. Even though no differences in E/A ratio and Tei index were found between the two groups, only E/E’ was elevated in the group with LVH compared to those without LVH p = 0.04  as well as normal subjects. A previous study showed that patients with WCH have increased cardiovascular risk in the aspect of target organ damage compared with a normotensive group . Howeverubgroups , 8.In the literature, the risk factor identified for LVH in hypertensive subjects was BMI. Many studies have been published concerning the development of LVH in obese children and adolescents. The pathophysiological mechanism of obesity-related LVH has been well described. In obese patients, increased metabolic requirements lead to an increase in preload and afterload to the heart and an adaptive increase in LVM to normalize the increased wall tension . ObesityDiastolic dysfunction is a well-described type of cardiovascular organ damage in pediatric patients with hypertension. Diastolic dysfunction progresses with myocardial fibrosis and ischemia in chronic systemic hypertension. Therefore, LV diastolic dysfunction with restriction in the left ventricular filling is considered a hallmark of hypertensive heart disease . SeveralABPM is considered superior to standard BP measurement in the evaluation of target organ damage related to hypertension . UsuallyIn this study, ABPM parameters, such as BP load and night dip, had no significant correlation with LVH or diastolic function. On the other hand, other studies suggested that the ABPM data of hypertensive and prehypertensive adolescents were associated with pathologically elevated LVMIs. They confirmed that LVMI is higher in sustained hypertensive adolescents than in normotensives, but the LVMI of white coat hypertensives did not differ . A recenIn this study, we defined essential hypertension as mean daytime systolic BP index ≥1.0. Several studies showed that daytime and 24-h average BP may indeed carry similar information for diagnosing hypertension in clinical practice , 18. FurHypertension is one of the most important modifiable risk factors in the development of cardiac diseases. In children, both physiological and pathological increases in blood pressure progressively modify the geometry of the left ventricle, causing a significant increase in its wall thicknesses. As essential hypertension is usually asymptomatic, cardiovascular damage is usually clinically silent in the early stages. However, cardiac mass is already subject to change during the early hypertensive stages . Hence, Potential limitations of the current study include the retrospective study design and a relatively small sample size. We did not collect all the echocardiographic data of all the subjects. Nevertheless, the fact remains that the results in this study are statistically significant. We did not compare essential hypertensive group to normal controls entirely. The retrospective study design precluded the evaluation of the subjects’ current BP status and cardiac function. These results are hardly applicable to different geographic populations. In addition, the LVMI and diastolic function were assessed by echocardiography and pulse-wave Doppler echocardiography, which is a less objective method than other precise techniques, such as cardiac MRI. Nonetheless, the imaging techniques we used are commonly used in clinical practice to detect LVH and LV diastolic dysfunction successfully.In conclusion, LVMI significantly correlated with BMI in children and adolescents with essential hypertension based on ABPM. However, the ABPM parameters of sustained hypertension did not predict left ventricular hypertrophy. LVH was related to LV diastolic dysfunction, as indicated by the elevated E/E’ ratio in children and adolescents with essential hypertension.


Background. Novel therapies need to be evaluated in a relevant large animal model that mimics the clinical course and treatment in a reasonable time frame. To reliably assess therapeutic efficacy, knowledge regarding the translational model and the course of disease is needed. Methods. Landrace pigs were subjected to a transient occlusion of the proximal left circumflex artery (LCx) (n = 6) or mid-left anterior descending artery (LAD) (n = 6) for 150 min. Cardiac function was evaluated before by 2D echocardiography or 3D echocardiography and pressure-volume loop analysis. At 12 weeks of follow-up the heart was excised for histological analysis and infarct size calculations. Results. Directly following AMI, LVEF was severely reduced compared to baseline in the LAD group  compared to only a moderate reduction in the LCx group  and this effect remained unchanged during 12 weeks of follow-up. Conclusion. Two models of chronic MI, representative for different patient groups, can reproducibly be created through clinically relevant ischemia-reperfusion of the mid-LAD and proximal LCx. The treatment of patients suffering from myocardial infarction (MI) is aimed at the preservation of cardiac function. Most treatment regimens directly target pathways that limit infarct size or reduce adverse remodeling, thereby preventing progression into heart failure (HF) –3. To fuImportantly, due to optimized logistical and diagnostic health care, the complaint-to-needle time has decreased considerably in the western world . This haTo create both a moderate and a severe model of chronic myocardial infarction that resemble these different patient groups, ischemia can be induced in several ways. These include permanent ligation, progressing occlusion by placement of ameroid constrictors, a bottleneck stent model, and coiling or infusion of ethanol in the target coronary artery –18. HoweIn most ischemia/reperfusion models, the left anterior descending artery (LAD) is occluded, which is associated with a high mortality rate during infarct induction and reperfusion due to ventricular fibrillation (VF) , 21. As To determine the long-term course of cardiac function in a moderate LCx and a severe LAD ischemia-reperfusion model for future validation of novel therapeutic strategies, we hypothesized that LAD ischemia-reperfusion will result in fast development of cardiac dysfunction representing a good model for severely affected patients with cardiac dilatation and signs of heart failure. Secondly, we hypothesized that the LCx ischemia-reperfusion model leads to a moderately affected heart representing a large patient group that has been adequately revascularized after an initial ischemic event but could still benefit from additional therapy.All procedures were approved by the local animal welfare committee of the University of Utrecht . A total of 12 female specific pathogen free (SPF) landrace pigs were included . The pigs were housed in the experimental animal facility at the University of Utrecht  in a group prior to procedure and individually after the AMI (to prevent hostile behavior after infarct procedure). The animals were checked by a veterinarian upon arrival at the facility and daily scored by a biotechnician and once a week by a veterinarian during follow-up. Six animals were randomized to undergo ischemia-reperfusion of the LCx and 6 animals were randomized to undergo LAD ischemia-reperfusion.All animals received dual antiplatelet therapy  and antiarrhythmic drugs  starting 10 days prior to infarct induction up until sacrifice at 12 weeks of FU.µg/kg/h , and pancuronium 0.1 mg/kg/h . Upon infarct induction, all animals were therapeutically heparinized with 2 doses of 5000 IE . All pigs received a fentanyl patch  and meloxicam  0.5 mg/kg/d, as postsurgery analgesia.General anesthesia was induced with an intramuscular injection of 0.5 mg/kg midazolam , 10 mg/kg ketamine , and 1 mg of atropine  and maintained with intravenous infusion of midazolam 0.5 mg/kg/h, sufentanil 2.5 Animals were randomized before the start of the procedure via sealed envelopes. Cardiac function at baseline was quantified by 2D echocardiography and pressure-volume (PV) loop analysis. Blood was sampled before AMI and 6 hours after for troponin I analysis. All animals received a Reveal event recorder .An 8F sheath was inserted in the carotid artery and an 8F guiding catheter  was positioned at the ostium of the left main coronary artery. An angioplasty balloon  was inflated (8–14 bar) for 150 min in the proximal LCx . After bAn anteroseptal myocardial infarct was induced during an open chest procedure in order to reduce periprocedural mortality due to VF. The thorax was opened via sternotomy. The infarct was induced by a transient ligation of the mid-LAD after the first diagonal for 150 min. All pigs subjected to LAD ischemia-reperfusion underwent a 3D epicardial echocardiography before and after infarct induction.During the 12 weeks of FU, a 2D echocardiography was performed at 4 and 8 weeks of FU under induction medication as described above. Twelve weeks after infarct induction the animals were anesthetized, and 2D and 3D epicardial echocardiography were performed followed by invasive PV loop measurements. The animals were sacrificed and the hearts were excised for infarct size determination and histological analyses.Echocardiography was performed using a Phillips iE33 echocardiography machine . 2D images were obtained of the parasternal long axis and parasternal short axis at basal, mid-ventricular, and apical level. The 2D echo was repeated after infarct induction in the animals with LCx infarction. This was not possible in the LAD group because of fluid and air in the chest after open chest procedure. Additionally, a 3D epicardial echocardiogram was performed in the LAD ischemia-reperfusion before and after myocardial infarction as previously described . In bothAbED)∗L/3 + (AmED + ApED)/2)∗L/3 + 1/3(ApED)∗L/3; LV end-systolic volume ((LVESV) = (AbES)∗L/3 + (AmES + ApES)/2)∗L/3 + 1/3(ApES)∗L/3, in which Ab is the area at basal level, whereas Am and Ap are the areas at mid and apical levels, resp, and L is the length of the ventricle) [Images were analyzed using Velocity Vector Imaging . The end-diastolic and end-systolic volumes were calculated by the modified Simpson rule (LV end-diastolic volume ((LVEDV) = (ntricle) . LVEF wa3D echocardiographs were analyzed offline using Qlab 10.1 software  as described before . One fulStrain is defined as the total deformation of the myocardium during 1 cardiac cycle , 26. RaddP/dt max, and prerecruitable stroke work) and diastolic indices . Analyses were performed using Conduct NT analyses software version 16.1 .A 7F conductance catheter  was placed under fluoroscopic guidance in the apex of the left ventricle as previously described . PressurTroponin I levels were quantified using a standardized ELISA protocol of the clinical chemistry laboratory of the University of Utrecht.After the heart was excised, the atria were removed and the ventricles were cut into 5 slices of approximately 1 cm thickness. The heart was stained using 5% tetrazolium chloride solution for 10–15 minutes at 37°. The slices were photographed and infarct size was calculated using automatic computer assisted image analysis software  as described before . InfarctBiopsies were taken from the infarct area, the infarct border zone, and the remote myocardial segments followed by embedding into paraffin for further light microscopical analysis. Collagen content in infarct, border, and remote myocardial segments was assessed by trichrome stain. Briefly, all sections were deparaffinised and fixed in Bouin's fixative  at 56° for 15 minutes. Nuclei were stained with haematoxylin for 3 minutes. The slides were submerged in Trichrome-AB solution for 5 minutes after which they were treated with 0.5% acetic acid for 1 minute. Slides were mounted with Entallan . Three random pictures were made at a 10X magnification and collagen content was calculated as percentage collagen of total surface area using automated analysis software .2O2 solution for 30% and incubated with SMA 1 : 1000 overnight. Subsequently, the slides were incubated with secondary HRP-conjugated goat anti-mouse antibody dilution 1 : 200  for 90%. All slides were immersed in DAB solution for 2 minutes  and mounted with Entallan. A technician that was blinded for group allocation took 3 random pictures at 10 times magnification. Arterioles per field of view were counted and expressed as number per view.Arteriole density was quantified in infarct, border, and remote myocardial segments, using alpha smooth muscle actin immunohistochemistry analysis . Endogenous peroxidase activity was blocked by 3% methanol/H4  overnight. Subsequently, the slides were immersed in DAB solution and mounted with Entallan. Photographs were taken at 20X magnification and number of capillaries per mm2 was calculated.Capillary density was only assessed in border in and remote areas, because almost all capillaries are destroyed after AMI. All sections were deparaffinised and pretreated with trypsin EDTA . Endogenous peroxidase activity was blocked as described above. All slides were incubated with Isolectin B t-tests or Mann-Whitney U tests. For sequential data, a two-way repeated measures ANOVA was applied. Correlations were analyzed by Pearson's correlation coefficient. P < 0.05 was considered statistically significant.All data were analyzed using SPSS Statistics 20 . All data are presented as mean ± SEM. Comparisons between groups at a single time point  were analyzed using Student'sP = NS). This animal died of ventricular fibrillation during infarct induction, resistant to defibrillation. Fifty percent of the animals in the LCx group needed defibrillation during infarct induction with an average of 7.8 times, as compared to 5/6 animals in the LAD group with an average of 12.2 times defibrillation. During the 12 weeks of FU period, none of the animals died or were treated for heart failure. No ventricular arrhythmias were recorded on the Reveal detector during the 12 weeks of FU.All animals that underwent LCx occlusion survived initial infarct induction (100%) compared to 5/6 animals in the LAD group  in the LCx group and with 17.1% to an average of 39.4 ± 1.6% in the LAD group (P = 0.009). Following AMI, LVESV increased with 5.6 ± 2.0 mL (P = NS) in the LCx group and with 17.8 ± 6.7 mL (P = 0.01) in the LAD group (Both LVEF and LV volumes before infarct induction were comparable between the LCx and LAD group. Post-AMI LVEF decreased with 5.9% to 50.8 ± 1.6% (AD group . There wP = 0.06) in the LCx group whereas LVEF of the LAD group declined with 14.7% to 41.7 ± 1.5% (P < 0.001). LVESV increased nonsignificantly in the LCx group with 10.7 mL to 46.0 ± 2.4 mL (P = 0.06), where the LAD group did show a significant increase of 30.6 mL to 60.7 ± 4.1 mL (P < 0.001). No significant dilatation as measured by LVEDV was seen in the LCx group . LVEDV in pigs subjected to LAD occlusion, however, was significantly increased during follow-up . At 12 weeks of FU, 3D echocardiography confirmed the 2D echocardiography measurements . The total ventricular strain at 12 weeks of FU was significantly lower in this group at 12 weeks of FU . These findings corroborate with the LVEF echocardiography data. Circumferential strain was significantly reduced in the LAD group in the apex and at mid-ventricular level of the heart throughout the 12 weeks of FU compared to baseline  and ESPVR (derivative of contractility) were significantly decreased in the LAD group but not in the LCx group . The average infarct size in the LAD group was significantly higher than in the LCx group .Invasive real-time PV loop analysis was also performed at baseline and 12 weeks of FU. Cx group . IndicesThe potential effects of novel therapeutics that confine the damage after MI depend on the severity of the ischemic event . To deteAs hypothesized, the two models showed a marked difference in response to ischemia-reperfusion. First, in the LCx model, none of the animals died which was, most likely, based on fewer episodes of VF. Presumably this is due to the involvement of the septum in the infarct area in the LAD model combined with a smaller area at risk after occlusion of the LCx. This difference in the area at risk also resulted in a large difference in infarct size, which was approximately 23% of the LV in the LAD model compared to 10% in the LCx model. In turn, the larger infarct size in the LAD model resulted in a profound decrease in LVEF culminating in adverse remodeling and cardiac dilatation. The decrease in LVEF occurred to a lesser extent in the LCx group and this did not result in any cardiac dilatation after MI. In concordance with the functional echocardiography data, myocardial strain was decreased in the affected myocardial segments in the LAD group, whereas strain was preserved in the affected segments in the LCx group. To the best of our knowledge, this is the first study that has studied myocardial strain when comparing different MI models and these findings show that the two models are not only different regarding the global cardiac function but also differ on a regional contractile level. Despite the significant differences in systolic function in the LAD group, no differences between the groups were observed regarding diastolic dysfunction. In both studies, diastolic dysfunction worsened relative to baseline measures, which suggests that these measurements are very robust and are not directly influenced by infarct size or dilatation in the current study.In a previous study of Suzuki et al. in which the mid-LAD was occluded for 60 minutes followed by reperfusion, a comparable mortality 16%) and decrease in cardiac function were observed following infarct induction . However% and decDespite our best efforts, the study has some limitations. First, we assessed cardiac function by 2D echocardiography during follow-up and obtained 3D echocardiogram directly after MI (LAD-model only) and at sacrifice (both models). Due to the anatomical position of porcine ribs, it is not possible to obtain a transthoracic 4 chamber view that would be needed for 3D echocardiography. Although cardiac MRI is considered the gold standard for cardiac function and volumes, due to logistic reasons, it was not feasible to obtain sequential cardiac MRI data in our study. We are confident that our echocardiography data are reproducible and depict the true cardiac function following both ischemia-reperfusion models. Second, in one group we performed a closed chest balloon occlusion model and in the other group an open chest model was applied. The latter was chosen in order to be able to perform epicardial defibrillation in the LAD model to improve survival in the LAD model. Since the study was not designed to directly compare these two models, a similar infarct induction was, however, not essential.To conclude, the current study showed that it is feasible to create two very distinctive models of chronic myocardial infarction to test novel therapeutics after MI for the possible treatment of different patient groups. Reperfusion after 150 min ischemia of the LAD leads to severe cardiac dysfunction and the development of heart failure over a limited period of time, whereas ischemia-reperfusion of the LCx culminates in stable, moderate cardiac dysfunction. Since these models closely resemble the clinical course and treatment of MI and enable intracoronary therapy administration, they are preferable to models with persistent coronary occlusion. This study adds to refinement of preclinical studies which hopefully will result in improved translational medicine and a reduction of animals needed in preclinical research.


Background. Diabetic cardiomyopathy (DCM) is always accompanied with alteration of left ventricular structure and function. The aims of this study were to assess the structural remodelling in patients with DCM by cardiovascular magnetic resonance (CMR) and correlation of structural remodelling with severity of DCM. Methods. Twenty-five patients  with DCM and thirty-one normal healthy controls  were scanned by CMR cine to assess function and structure of left ventricular. Length of diabetic history and results of cardiac echocardiography  were also measured. Results. Compared with normal controls group, DCM group was associated with significantly increased ratio of left ventricular mass at end diastole to end-diastolic volume (MVR) (P < 0.05) and no significant difference was in mass at end diastole (P > 0.05). The ratio correlated with both length of diabetic history and echocardiographic Doppler tissue imaging E′ . Conclusions. CMR can be a powerful technique to assess LV remodelling, and MVR may be considered as an imaging marker to evaluate the severity of LV remodelling in patients with DCM. Type 2 diabetes mellitus (T2DM), one of the most common chronic diseases, affects nearly four hundred million people in all countries . As estiFor a long time, LV remodelling has been assessed by echocardiography –8. But tThere has not been widely accepted in normal range of MVR measured by CMR, let alone in patients with DCM. The special aims of this study were to investigate the LV remodelling in DCM patients by CMR and correlating between LV remodelling and diabetic history.2, (b) age < 30 years, or >70 years, and (c) other standard CMR contraindications, such as claustrophobia or any history of body metal implant. Two candidates quitted because of high heart rate during being scanned. Therefore, a total of 25 patients were enrolled. At the same time, thirty-one age- and gender-matched normal healthy controls from community were recruited by their own volition to this study. All patients and normal controls were gave the informed consent, which were conducted in accordance with the Declaration of Helsinki (1964). This study was approved by the Institutional Review Board of Southwest Hospital .Twenty-five patients with diabetic cardiomyopathy were recruited from June 2015 to March 2016 at Southwest Hospital of Third Military Medical University. The inclusion criteria included (a) first diagnosis of type 2 diabetes mellitus with the criteria from World Health Organization , (b) decα-hydroxybutyrate dehydrogenase (α-HBDH), creatine kinase (CK), ischemia modified albumin (IMA)), and markers of myocardial damage (troponin and myoglobin) were assessed in 86% patients and controls. Urine microalbumin (U-MTB) was also measured in the majority of participants (79%).All DCMs and normal controls were measured height, weight to yield body surface area (BSA) and body mass index (BMI), and systolic and diastolic blood pressure. Serum glucose, HbA1c, pancreas function , renal function (blood urea nitrogen (BUN), creatinine, and cystatin C), lipids profile ) were analyzed. Myocardium zymogram examination (aspartate aminotransferase (AST), lactate dehydrogenase (LDH), All DCMs were performed transthoracic echocardiography at rest by a commercial ultrasound machine  and a matching transducer (S5-1 heart probe). According to the American Society of Echocardiography's recommended guidelines , assessmAll DCMs and healthy controls were scanned by CMR on a 3.0 T whole-body system  in the supine position and head first with a matching 12-channel matrix body coil and electrocardiographic gating instrument. Breath held in expiration when necessary. The localizing images, including standard four-chamber , two-chamber (left ventricular and left atrium), and short-axis images, were obtained.2, flip angle 50°, matrix size 256 × 179, voxel size 2.2 × 1.6 × 6.0 mm3, slice thickness 6 mm, spacing between slices 1.5 mm, and 25 phases per cardiac cycle) [Segmented short-axis cine images were acquired with two-dimensional (2D) steady-state free precession (SSFP) pulse sequence  . To coveCine images were analyzed offline using the dedicated commercial available software  by two experienced observers (one with 10 years of experience in CMR and the other 6 years of experience) without knowing any information of the participants. After all short-axis cine images of LV were loaded, the end-systolic (ES) phase and end-diastolic (ED) phase were visually identified as the smallest and largest chamber area separately on the middle slice. The myocardial endocardial and epicardial contours of LV were carefully manually delineated on all images  to acquit-test was used to evaluate the differences in function parameters and demographic variables between the DCMs and normal. Mann-Whitney U test was used to evaluate the differences in biochemical variables if the variables did not fit normal distribution or standard variance was heterogeneity. The relationship between MVR and diabetic history was analyzed by Pearson's or Spearman's method. Statistical tests were two-tailed, and P < 0.05 was considered to reach statistical significance. Statistical analysis was performed on the commercial available software .Categorical variables were showed as percentage. Kolmogorov-Smirnov test was used to test normality of variables, and variables that did not fit normal distribution were summarized as median and quartile. Variables, which were continuously and normal distribution, were presented as mean and standard deviation (SD). Independent sample Results of demographic and biochemical characteristics were showed in P > 0.05).Twenty-five patients  with DCM, and thirty-one normal controls  were studied. Fasting blood glucose and glycated hemoglobin significantly increased in DCMs. Insulin and C peptide were also elevated in DCMs. DCMs were also accompanied by higher triglycerides, HDL, and aspartate aminotransferase (AST). IMA and troponin were higher in DCMs, which showed possible impairment of myocardium related to T2DM. Age, gender, weight, height, BSA, BMI, blood pressure, and renal function  were similar in the two groups . There was no significant difference in LV massi at ED between the two groups . MVR increased by 15% in DCMs .The LV EDVi approximately decreased by 10% in DCMs . DCM patients were similar in SVi, CI, and EF to normal controls (All P > 0.05), which revealed that systolic function of LV did not impair in DCMs. Echocardiography DTI showed that DCMs were associated with decreased E′/A′ (mean 0.80 ± 0.09).The LV ESVi was also smaller in DCMs . Spearman correlation showed that MVR was negatively correlated with echocardiography DTI E′ , although the correlation between MVR and E′/A′ did not reach statistical significance.Pearson correlation analysis showed that MVR was positively correlated with the length of diabetic history (Diabetic cardiomyopathy is regarded as T2DM-related myocardial dysfunction, which is independently of CHD, valvular dysfunction, and hypertension , 4. In aAs reported in previous study –20, therLV concentric remodelling, a kind of patterns of LV remodelling, was characterized by an increased ratio of LV mass to volume and normal LV myocardial mass index at ED . For a lIt is intriguing that MVR was correlated with length of diabetic history, not age, blood pressure, changed AST, IMA, triglycerides, HDL, insulin, C peptide, glucose, and even HbA1c. Transient hyperglycemia can make persistent impairment to cell by disrupting signal feedback loop . HBA1c, 2 were recruited, and this inhomogeneity of patients may introduce a bias.There were some limitations in our study. First, the number of recruited patients and normal controls was small, and this study should be considered as preliminary. Large cohort or cross-section studies should be conducted to confirm the influences of diabetic history on LV remodelling. Second, patients only with GFR ≥ 30 mL/min/1.7 mCMR can be a powerful technique to assess LV remodelling, and MVR may be considered as an imaging marker to evaluate the severity of LV remodelling in patients with DCM.