Anthracycline-induced cardiotoxicity is well-known as a side effect of chemotherapy. Currently, clinical imaging techniques are not capable to detect doxorubicin (DOX)-induced cardiotoxicity before a functional decline. The purpose of this study was to evaluate whether myocardial contrast echocardiography (MCE) can dynamically monitor the cardiac changes in the early stage in the DOX-induced rat model of cardiotoxicity.A weekly injection of 2.5 mg/kg of DOX was used to generate a rat model of cardiotoxicity. All groups underwent ultrasonic examinations including standard echocardiography, 2D speckle tracking echocardiography (2D-STE), and MCE. Then all rats were sacrificed immediately for histopathological evaluation.P = 0.048) and β  were observed after 2 and 4 weeks of treatment, respectively, while left ventricular global strain  decreased after 6 weeks of treatment and left ventricular ejection fraction (LVEF)  decreased after 8 weeks of treatment. The main histopathological features are increased myocardial vacuolization and interstitial fibrosis and decreased myocardial microvessel density.A total of eight control rats and 32 DOX-treated rats were included in the study and grouped according to their treatment period. Decreased quantitative parameters of myocardial blood flow (MBF) (control vs. group 1: 133.31 ± 20.23 dB/s vs. 103.35 ± 21.60 dB/s, Compared with standard echocardiography and 2D-STE, MCE can accurately and non-invasively detect changes in early myocardial perfusion, demonstrating the clinical potential of continuous and dynamic monitoring of DOX-induced cardiotoxicity. Doxorubicin (DOX), a typical anthracycline, is generally used for treating numerous solid tumors, such as those of the breast, ovary and gastrointestinal tract, and hematological malignancies , 2. DOX In vitro studies have shown that DOX exposure can lead to endothelial cell damage by increasing reactive oxygen species (ROS) production and directly mediating DNA damage , usually acquired by conventional echocardiography, is a routine and convenient indicator for monitoring cardiac toxicity during cancer treatment –11. In rBy observing microbubble destruction and replenishment in the myocardium, myocardial contrast echocardiography (MCE) can non-invasively assess myocardial microcirculation perfusion . As coroTo further study the relationship between myocardial perfusion and the occurrence and development of DOX-induced cardiotoxicity, and to find imaging indicators for the early identification of cardiotoxicity, we applied MCE to the rat model of DOX-induced cardiotoxicity. We continuously and dynamically monitored the changes in relevant quantitative parameters of MCE before and during the treatment to observe obvious changes in LV systolic function and histopathology.Animal care and use committee approval were obtained from Army Medical University for all experimental protocols. The study design is summarized in During all echocardiographic examinations, volatile isoflurane  was used for anesthesia. The rats were first anesthetized in the induction box, and then placed in the supine position on the physiological information monitoring platform and an anesthesia concentration of 1–2% was maintained. Heart rate was kept constant at 350–370 beats/min and body temperature at 37°C throughout the experiment. Electrodes were fixed on the paws for continuous ECG monitoring and a shaver was used to remove anterior chest hair. The best parasternal long-axis view was selected, that is, the mitral valve, the aortic valve, and the maximum LV area were displayed.This study used an ultrahigh resolution small animal imaging system  equipped with a linear array probe  with a frequency of 24 MHz to acquire conventional transthoracic echocardiography images. When the papillary muscles are viewed in a parasternal long-axis view, LV wall thicknesses and chamber diameters and volume in end-diastole and end-systole, LVEF, LV fractional shortening (FS), and LV mass (LV mass) were determined by M-mode tracings. The flow velocity of the mitral valve was measured on the four chamber cardiac plane, the sampling frame was located on the level of the mitral valve, and the spectral Doppler image was obtained. The peak flow velocity (E), the isovolumic systolic time (ICT), the isovolumic diastolic time (IRT), and the LV ejection time (ET) were measured in the early diastole phase of mitral valve action, and tissue Doppler was measured at the junction of the ventricular septum and the mitral annulus to obtain the myocardial motion velocity (e’). The ratio of E to e’ (E/e’) and the Tei index, (ICT + IRT)/ET, were calculated .By adjusting the scanning range, parasternal short- and long-axis views with the highest frame rate were recorded using B-mode to ensure the best possible visualization of the entire LV myocardium for 2D-STE analysis. Images of at least three cardiac cycles were acquired and analyzed using TomTec software . The software automatically tracks the endocardial and epicardial boundaries and divides the equally spaced myocardial segments. The overall myocardial strain is the average value of each segment, excluding the images with poor tracking quality. In the parasternal long-axis plane, the LV global longitudinal strain (GLS) was obtained ; in the 8/ml. Following the instructions provided by the manufacturer, the solution was prepared by diluting with 5 ml sodium chloride 0.9%. The contrast agent was continuously infused at a rate of 0.3–0.4 ml/min into a tail vein using a dedicated pump  and a 24-gauge cannula , 59 mg/tube, was selected as the contrast agent. SonoVue consists of a suspension of microbubbles of stabilized SF6, which have an average size of 1–10 μm and a number of 2–5 × 10 cannula .For real-time MCE, we used a Philips EPIC 7 ultrasound diagnostic system  and a linear array probe (eL18-4) with a frequency of 20 MHz. A set of pre- and post-processing settings was optimized for each rat: a focus was placed on the middle of the LV for the near field, the penetration depth was set to 2 cm, gains were adjusted to acquire images with no signal in the myocardium, and the dynamic range was set to maximum (60 dB). The above conditions were held constant for each experiment. In the myocardial contrast mode, the mechanical index (MI) was adjusted to 0.06, and the tail vein was continuously infused with SonoVue suspension. After filling the LV myocardium with a contrast agent, the “flash ” was triggered to burst the ultrasound microbubbles in the myocardium, followed by automatic switching to the real-time low-energy contrast mode. The LV parasternal long-axis ultrasound cine loops were acquired, and continuous digital images of at least 20 cardiac cycles after flash were stored for quantitative analysis.2 (Y = A (1−e−βt) + C  workstation. On the first frame image after “flash,” regions of interest were fixed on the middle segment of the LV anterior myocardium with an area of approximately 1.5 mm2  and manu−βt) + C , in whic−βt) + C .2 gas chamber after undergoing MCE, then euthanized by thoracotomy and heart removal. The heart tissue was fixed in 4% neutral buffered formalin immediately. After being fixed for 48 h, the heart was continuously sectioned along the long axis of the LV papillary muscle (4 μm thick), which was similar to the MCE plane. Histomorphological changes in cardiac tissue were examined using hematoxylin and eosin (H&E) staining. The development of fibrosis in cardiac tissue was visualized using Masson’s trichrome staining. Myocardial vessels were assessed using CD31 staining (Abcam ab182981). The above pathological examination was evaluated by a pathologist who was blind to the ultrasonic results.All rat was anesthetized and put into an enclosed COpost hoc test was performed for multigroup analyses. To assess the intra-observer and inter-observer variabilities in myocardial perfusion parameters, the intraclass correlation coefficient (ICC) and Bland-Altman statistics were used by means of two blinded examiners. Statistical significance was determined by a p-value of < 0.05. All data were analyzed using SPSS statistics version 23.0  and plotted using GraphPad Prism software 8.0 .The distribution of the data was assessed using the Shapiro–Wilk test, and the homogeneity of variance was evaluated using Levene’s test. The mean ± standard deviation is used to express continuous and normally distributed variables. The data were subjected to one-way ANOVA and Bonferroni In this study, 40 rats were included in total. Eight rats were sacrificed immediately after ultrasound examination at baseline for pathological evaluation. The remaining rats were subjected to routine echocardiography, MCE, and pathological evaluation after 2, 4, 6, and 8 weeks of DOX intraperitoneal injection. After DOX injection, some rats exhibited arrhythmia, ascites, hepatomegaly, and diarrhea.P = 0.11). FS was significantly decreased in 8-week DOX treatment groups , and LVEF was also reduced in group 4 . The DOX-treated rats showed a significantly higher LV mass  compared to control rats. Wall thickness had no significant difference between the control group and the DOX-treated groups. After 6 weeks of DOX treatment, E/e’ increased from 13.16 ± 1.46 at baseline to 16.23 ± 2.06 (P = 0.038). At 8 weeks, E/e’ increased to 16.46 ± 2.93 (P = 0.021). After DOX was administered for 6 weeks, the Tei index in the group of treated rats was significantly higher compared to the control group . After DOX was administered for 8 weeks, the Tei index was further increased to 0.66 ± 0.08 (P < 0.001).The physiological and cardiac function measurements are presented in P = 0.002) (P = 0.001) (P = 0.004), and GRS decreased from 45.54 ± 4.55% to 33.09 ± 6.90% (P < 0.001) (The LV strain parameters in the DOX treatment groups were significantly reduced than that of the control rats . After D= 0.002) . After D= 0.001) . Meanwhi< 0.001) .P = 0.048) (P < 0.001) (P < 0.001) (P < 0.05)  . At 4 we< 0.001)  and MBF < 0.001)  were dec < 0.05) .Histopathological changes were found in the DOX-treated groups. HE staining of group 1 samples  displayed cardiomyocyte vacuolization  without P = 0.001), β , and MBF . Similar, although slightly worse, concordance values were found for the interobserver evaluation: MBV , β , and MBF . The Bland-Altman analysis also presented a great agreement between intra-observer and inter-observer, as shown in A reproducibility analysis was conducted with 10 randomized rats. In terms of the intra-observer variability, there was an excellent ICC for MBV (0.808; 95% CI 0.428–0.948, Anthracycline is prominent as an antitumor chemotherapy drug, but cumulative dose-related cardiotoxicity constrains its treatment applications in the clinic . The curMCE was performed in a rat model of cardiotoxicity at different treatment periods, and the rats were immediately sacrificed to verify changes in histologic results. In this study, we found from using MCE that β and MBF were decreased at 4 and 2 weeks following treatment with DOX, respectively. However, GLS, E/e’, and Tei index were increased at 6 weeks, and EF and FS were reduced at 8 weeks. Accordingly, compared to either strain value or LVEF, β, and MBF had a higher diagnostic value and correlated well with the histologic findings.In the current study, rats were treated for 2-, 4-, 6-, and 8- consecutive weeks with a dose of 2.5 mg/kg DOX once a week. Similar i.p. doses were also used in previous studies that have been shown to cause cardiotoxicity in rats , 28. ComIn the echocardiographic assessment of LV function, myocardial strain, including GLS, GRS, and GCS can be used to quantify global and regional myocardial deformation or strain with less dependence on volume loading, size, scan angle, and geometry of the LV and with greater accuracy than the traditional measures of FS and EF . The AmeMCE is a technique that can be used to evaluate myocardial tissue microcirculation perfusion in various ranges of situations. By using it, we can evaluate microcirculation perfusion in real time, estimate the volume of myocardial capillaries, and determine whether myocardial blood perfusion is well-distributed . MCE quaIn our model, differences in cardiac function, cardiac strain, and cardiac perfusion were detected between animals receiving different cumulative doses. Based on MCE, we observed that the change in myocardial perfusion precedes the change in LV strain against DOX-induced cardiotoxicity in a rat animal model. Our results extend observations to demonstrate an early imaging marker in DOX-induced cardiotoxicity, opening promising new prospects for the diagnosis and treatment of DOX-induced cardiotoxicity in patients treated with antitumoral chemotherapy.In the present study, vacuolization of cardiomyocytes and increased myocardial interstitial fibrosis was observed in the DOX treated groups. Myocardial microvessel density was found to be significantly reduced according to histopathology. These results are consistent with those of previously published findings , 48–50.There are some limitations in the present study. First, the DOX route of administration is not ideal because the present study used the intraperitoneal route rather than the intravenous route to treat patients with cancer. Second, unlike patients with cancer who develop DOX-induced cardiotoxicity, most of whom are elderly individuals, the rats used in this study are healthy and free of comorbidities. Finally, the pathophysiological process of DOX-induced early myocardial perfusion injury is still unclear. Furthermore, there is still much work to be done to determine the molecular and cellular mechanisms behind these findings.In the present study, we find that the earliest ultrasonic event according to MCE is the change in myocardial perfusion. Myocardial strain and cardiac function are normal at the early stage and do not change until later during the development of cardiotoxicity although deterioration of diastolic function, Tei index, and LVGLS occur prior to a substantial reduction in LVEF. Alterations in these parameters that reflect MCE may have the potential as a non-invasive technique in the evaluation of early and dynamic cardiac changes.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The animal study was reviewed and approved by the Institutional Animal Care and Use Committee at Army Medical University.JZ and XL contributed to the experiment, the data analyses, and wrote the manuscript. JL and LT contributed to the experiment. YS contributed to the study design and manuscript editing. YG contributed to the study design and manuscript writing—review and editing. All authors read and approved the final manuscript.


Mitral e′ and TR peak velocity showed no association. The ASE/EACVI algorithm  demonstrated reasonable ability (AUC = 0.69) and 68% accuracy to identify elevated LV filling pressure. LASr displayed strong ability to identify elevated PCWP (AUC = 0.76). Substituting TR peak velocity for LASr in the algorithm  resulted in 91% feasibility, 81% accuracy, and stronger agreement with invasive measurements. Employing LASr as per expert consensus  and adding LASr to conventional parameters  also demonstrated greater feasibility  and overall accuracy  to estimate elevated PCWP.Near-simultaneous echocardiography and right heart catheterization were performed in 210 patients with EF ≥50% in a large, dual-centre study. Elevated filling pressure was defined as invasive pulmonary capillary wedge pressure (PCWP) ≥15 mmHg. LASr improves feasibility and overall accuracy of the ASE/EACVI algorithm to discern elevated filling pressures in patients with preserved EF.LAS  Smiseth, 1 Doppler echocardiography is integral to routine evaluation in the setting of suspected HF and provides vital information on cardiac size, left ventricular (LV) performance, and valvular function. In the setting of HF with preserved ejection fraction (EF) (HFpEF), Doppler imaging combined with 2D echocardiography provides information on LV filling pressure critical to diagnosis and optimal therapy regulation.Chronic dyspnoea and fatigue are common symptoms in heart failure (HF) and pose a significant diagnostic challenge. These typical HF symptoms are often non-specific and lack accuracy to be independently employed for diagnosis, necessitating additional investigations.2 Studies evaluating the diagnostic accuracy of this algorithm in patients with normal EF, however, are limited and suggest poor or modest performance.3–6 Left atrial reservoir strain (LASr) has been proposed as a novel, non-invasive diagnostic for grading diastolic dysfunction severity in patients with preserved EF.7 In a recent study, Inoue et al.8 demonstrated that LASr and LA pump strain demonstrate stronger ability to identify elevated filling pressures than conventional echocardiographic measures in a large HF population. However, LASr displayed generally poorer diagnostic performance in patients with preserved when compared with reduced LV systolic function in this study. Subsequently, the EACVI recommendations for multimodality imaging in HFpEF have suggested that incorporating LASr into the ASE/EACVI diagnostic algorithm may improve its diagnostic performance.9In 2016, the American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) introduced an algorithm incorporating multiple common echocardiographic variables to ascertain LV filling pressure status.r to the 2016 ASE/EACVI diastolic algorithm in a large, dual-centre, haemodynamic database of patients with unexplained dyspnoea, and preserved LV EF employing invasive Pulmonary capillary wedge pressure (PCWP) as reference.With this background, we examined the additional diagnostic value offered by LAS10 Patients were evaluated at two referral centres in Sweden; Karolinska University Hospital in Stockholm between 2014 and 2018, and Norrlands University Hospital in Umeå between 2010 and 2015. All subjects were haemodynamically stable during assessment. Prior to inclusion, we excluded patients with acute coronary syndrome, valvular prosthesis, and left bundle branch block. Thereafter, we excluded specific conditions where diastolic function assessment using the ASE/EACVI algorithm has significant limitations.2 This included patients with atrial fibrillation, pacemaker, hypertrophic or restrictive cardiomyopathy, and those that had undergone a heart transplantation or presented with >mild concomitant mitral valve disease. Finally, we excluded patients with EF <50% or poor echocardiographic image quality. Study protocol was approved by the local ethics committee at each centre . All patients provided written informed consent.We retrospectively analysed all patients enrolled in the KARUM study, a dual-centre database of patients with unexplained dyspnoea undergoing near-simultaneous echocardiography and right heart catheterization (RHC). Details of the total KARUM cohort have been previously published.11 Pharmacological status was unaltered between echocardiography and catheterization. Digital loops were stored and analysed offline  by experts (A.V. and P.L.) blinded to catheterization data. Mitral inflow interrogation was performed using pulsed-wave (PW) Doppler in the apical four-chamber view, placing the sample volume at the mitral leaflet tips. Transmitral early (E) and late diastolic velocities (A) were obtained and mitral E/A ratio computed. Doppler tissue imaging was utilized to measure early mitral annular velocities (e′) at both septal and lateral walls and subsequently averaged to calculate E/e′mean. Maximal tricuspid regurgitation (TR) peak velocity was measured using continuous-wave (CW) Doppler. Left atrial (LA) volume was obtained from apical four- and two-chamber views and indexed for body surface area.Comprehensive echocardiography was performed in both centres by experienced echocardiographers (A.V. and P.L.) employing commercial ultrasound systems  in keeping with current recommendations.2 In Step 1, diastolic function was evaluated considering recommended cut-offs provided for e′ , E/e′mean, TR peak velocity, and indexed LA volume and graded as normal (where <50% of the four echocardiographic parameters were positive), indeterminate (50% positive), or definite diastolic dysfunction (>50% positive). In Step 2, filling pressures were assessed as normal, indeterminate, or elevated among patients with diastolic dysfunction employing transmitral E-velocity and E/A ratio and supplemented by E/e′mean, TR peak velocity and indexed LA as recommended.2 LASr was assessed using 2D speckle tracking echocardiography in keeping with expert recommendation.12 In a non-foreshortened apical four-chamber view, the LA endocardial border was traced, taking care to exclude the appendage and pulmonary veins. The region of interest (ROI) was then visually inspected for quality of tracking, repeated if found inadequate and excluded if still suboptimal. Zero point was set at the onset of the QRS complex on the ECG. LASr was defined as the maximal inflection point above the baseline during ventricular systole and assigned a positive value. Acquisition of LASr using speckle-tracking echocardiography is illustrated in Figure 1.Assessment of diastolic function and filling pressure status was performed employing the recommended two-step ASE/EACVI approach.A wave and averaged from a minimum of five heart cardiac cycles. All pressure tracings were digitally stored and analysed offline using standard haemodynamic software package .RHC was performed immediately after echocardiography (within a 3-h period) during the same visit by experts blinded to imaging results at each centre using fluid-filled 6F Swan–Ganz catheters employing jugular or femoral vein access. Transducers were zeroed at mid-thoracic level in each patient. PCWP was measured at mid-r was performed in 40 randomly selected patients. Measurements were performed first by the same operator on two subsequent days considering the same heart cycle, and then by independent readers blinded to each other in addition to invasive pressure readings. Measurement variability was expressed in coefficient of variation and intra-class coefficients.Intra- and inter-observer variability analysis for LASQQ plots. Continuous variables were expressed as mean ± standard deviation for parametric variables or median (interquartile range) for non-parametric variables. Categorical variables were expressed as numbers and percentage. Correlations between PCWP and individual echocardiographic parameters were performed using the Pearson’s two-tailed test. Multiple linear regression models were generated to evaluate independent associations of echocardiographic variables with PCWP. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and overall accuracy were measured for each echocardiographic cut-off (as recommended by current guidelines)2 using standard definitions. Inter-technique agreement between echocardiographic algorithms and invasive PCWP was tested using calculated ĸ coefficients, where 0 to 0.2 was judged as slight; 0.21 to 0.4 as fair; 0.41 to 0.6 as moderate; 0.61 to 0.80 as good, and >0.8 as excellent. Receiver operating characteristics (ROC) analysis was employed to evaluate the discriminative potential of each echocardiographic variable, the ASE/EACVI algorithm, and modified algorithms incorporating LASr to identify PCWP ≥15 mmHg. Delong’s method13 was used to compare area under the curve between algorithms. IBM SPSS statistics version 23.0 was employed for analysis. A P-value <0.05 was considered statistically significant.Normality was tested using the Shapiro–Wilk test and visually reaffirmed using Figure 2. Of 480 patients referred for catheterization at both centres, 210 met the inclusion criteria. Characteristics of the patient population are presented in Table 1. Seventy-four (35%) patients had arterial hypertension, 18 (9%) had diabetes, 38 (18%) had ischaemic heart disease, 77 (37%) had pulmonary hypertension secondary to HF, and 125 patients (60%) had pulmonary parenchymal or vascular disease. Patients with PCWP ≥15 mmHg at rest  were older and more frequently diabetic and hypertensive. These patients demonstrated higher right atrial (RA) and pulmonary artery (PA) mean pressures on RHC with lower pulmonary vascular resistance (PVR) than patients with normal PCWP. On echocardiography, these patients demonstrated larger LV volumes and higher LV mass when compared with those with normal filling pressures. EF did not significantly differ between groups (P = 0.42). LV global longitudinal strain (LV-GLS) was significantly lower in the group with elevated PCWP (P = 0.01). When diastolic variables were compared, patients with elevated PCWP displayed higher mitral E-wave velocities, E/A ratio, E/e′mean ratio, indexed LA volume, and lower lateral e′ velocity . TR peak velocity and septal e′ velocities did not differ between groups (P > 0.05 for both comparisons). LASr was significantly lower in the group with elevated PCWP .A flow chart of patient selection in our study is presented in Table S1. Moderate significant correlations were observed between PCWP and mitral E-wave (r = 0.50), E/A ratio (r = 0.46), and E/e′mean ratio . Indexed LA volume demonstrated a mild significant correlation . TR and e′ velocities demonstrated no association with PCWP . LASr demonstrated a significant inverse relationship with PCWP  and a positive association with LV-GLS . Multivariable regression analysis was performed to assess independent correlates of PCWP. In the first regression model, we considered mitral E-wave, E/A ratio, E/e′mean ratio, and indexed LA volume. TR peak velocity, septal, and lateral e′ velocities were not considered in the model given absence of significant correlations with PCWP. In this analysis, E/A  and E/e′mean ratio  remained correlated with invasive PCWP . In the second model, when LASr was considered in addition to the above-listed variables, E/e′mean was no longer significantly associated with PCWP (P = 0.10). Here, mitral E-wave , E/A ratio , and LASr  emerged as independent variables associated with PCWP .Correlations of clinical and echocardiographic variables with invasive PCWP are presented in E/A ratio ≥2 demonstrated high specificity (96%) and accuracy (80%) to identify elevated PCWP. Sensitivity of E/e′mean, TR velocity, and indexed LA volume recommended cut-offs ranged from 40% to 98%, specificity from 21% to 86%, and accuracy from 38% to 75% (Table 2). TR peak velocity >2.8 m/s demonstrated poor specificity (28%) and accuracy (38%) in this analysis. On ROC analysis, mitral E wave, E/e′mean, and indexed LA volume demonstrated good ability to identify PCWP ≥15 mmHg . On the other hand, septal e′ (AUC = 0.46), lateral e′ (AUC = 0.60), and TR peak velocity (AUC = 0.52) demonstrated generally poor ability to identify PCWP ≥15 mmHg .Mitral r demonstrated a strong diagnostic ability to identify elevated PCWP . When multiple LASr cut-offs  were tested for highest discriminative accuracy, LASr <21% demonstrated optimally balanced senstitivity and specificity on ROC analysis, displaying 81% sensitivity, 64% specificity, and 67% accuracy to identify invasive PCWP ≥15 mmHg. However, higher overall accuracy (71%) was obtained when LASr <18% was considered . Additional sensitivity analysis was performed considering LV-GLS subgroups. In 206 patients where LV-GLS measurements were feasible, 63 (31%) demonstrated LV-GLS <16% and 143 (69%) demonstrated LV-GLS ≥16%. In the LV-GLS ≥16% group, LA reservoir strain at 18% cut-off displayed 65% sensitivity, 84% specificity, and 80% accuracy to determine PCWP ≥15 mmHg (Table 3). Table S3).LASr adds seperately to Step 1 (that identifies diastolic dysfunction) and Step 2 (that identifies elevated filling pressures) of the conventional diastolic algorithm. Step 1 could be assessed in 175 patients (83%), where all four variables  were available. In this analysis, 70 patients (40%) were classified as having normal diastolic function, 60 patients (34%) as indeterminate, and 45 (26%) as having diastolic dysfunction. Among those with indeterminate diastolic dysfunction, LASr cut-offs identified elevated PCWP with reasonable to good sensitivity (63% to 88% depending on cut-off employed) and modest accuracy (Table S4). Further, LASr improved overall accuracy of Step 1 in the ASE/EACVI algorithm, irrespective of cut-off chosen (Table 4).Next, we studied the additional value LASE velocity and mitral E/A ratio classified 26 patients (12%) as having normal, 167 (80%) as requiring additional criteria  and 17 (8%) as having elevated LV filling pressures. When additional parameters were also assessed, Step 2 of the ASE/EACVI algorithm classified 110 patients (52%) as having normal LV filling pressures, 23 patients (11%) as having indeterminate filling pressures, and 77 patients (37%) having elevated filling pressures. Step 2 of the ASE/EACVI algorithm demonstrated 71% sensitivity, 68% specificity, 68% accuracy, and -reasonable discriminative ability to identify elevated PCWP .Estimation of LV filling pressures employing Step 2 of the ASE/EACVI algorithm was feasible in 187 patients (89%). Assessment of transmitral r adds to the conventional diastolic algorithm to assess LV filling pressures using three different models. Salient findings of this analysis have been presented in Figure 5 and the Graphical Abstract. In Model 1, we substituted TR peak velocity >2.8 m/s  with LASr <18%. This approach  demonstrated higher feasibility (91% vs. 89%), overall accuracy (81% vs. 68%), and greater agreement with invasive measurements (ĸ coefficient 0.48 vs. 0.30) when compared with the ASE/EACVI approach (Table 5). Comparison of ROC curves demonstrated higher diagnostic performance to identify elevated filling pressures using Model 1 when compared with the conventional algorithm . In Model 2, in keeping with the EACVI recommendations for multimodality imaging in HFpEF,9 when one of the additional variables  were missing and the other two were conflicting, the missing variable was replaced with LASr. This approach  demonstrated higher feasibility than the ASE/EACVI algorithm (98% vs. 89%), in addition to marginally higher specificity (70% vs. 68%), accuracy (70% vs. 68%), and greater agreement with invasive measurements (ĸ coefficient 0.32 vs. 0.30). Finally, in Model 3, we considered LASr in addition to conventional parameters used in the ASE/EACVI algorithm. To clarify, after first evaluating filling pressures based on transmitral velocities and E/A ratio, we added LASr to the additional criteria . Using this approach, an elevated filling pressure status was assigned if >50% of the additional criteria (3 or 4) were found positive, and non-elevated if ≤50% (1 or 2) were found positive. This approach also demonstrated higher specificity (84% vs. 68%), accuracy (80% vs. 68%), agreement with invasive assessment (ĸ coefficient 0.47 vs. 0.30), and a tendency to higher diagnostic performance on ROC analysis  when compared with the ASE/EACVI algorithm (Table 5).We studied the potential value LASTable S2). TR peak velocity could be measured in 89% of cases. Measurement of LASr could be performed in 94% of patients. Double measurements in 40 randomly selected patients demonstrated a coefficient of variation of 10% with an intra-class correlation coefficient of 0.91 (95% CI 0.73–0.96). Test–retest analysis for LASr yielded a coefficient of variation of 12.8%.Measurement of echocardiographic surrogates of diastolic dysfunction in the ASE/EACVI algorithm were highly feasible  of patients with pulmonary hypertension of which 44% had left heart disease, the ASE/EACVI algorithm demonstrated high sensitivity and specificity  to identify elevated filling pressures, defined as PCWP >12 mmHg.18 The study, however, did not exclude all cardiac conditions where recommendations suggest that the ASE/EACVI algorithm is less reliable2 and this, in addition to a lowered PCWP cut-off, may have influenced sensitivity analysis. We chose to strictly mirror selection to exclude challenging sub-populations in keeping with recommendations.2 Despite careful patient selection, e′  and TR peak velocity demonstrated no significant association with invasive PCWP and poor ability to distinguish elevated filling pressure in our cohort. Lack of association of these specific variables with PCWP has been recently reported in another stringently selected cohort and may be attributed to the inclusion of patients with pulmonary disorders in both our and the above-mentioned cohort.6 Further, E/e′, which is widely utilized and has the most evidence as per recent systematic reviews3 demonstrated only a modest correlation with PCWP and showed no significant association with PCWP when LASr was introduced into our multivariable regression model.Since their introduction in 2016, the ASE/EACVI recommendations for evaluation of diastolic function have been validated in multiple cohorts but have shown conflicting results. Initial studies performed in patients with a wide spectrum of cardiac disease including both reduced and preserved EF suggest generally good diagnostic performance.6Differentiating HFpEF from pulmonary disease is a common clinical conundrum in patients presenting with unexplained breathlessness. While our findings may not be applicable to a general HFpEF population, they are consistent with what is seen in clinical practice at specialist PH centres and provide a real-world context. Furthermore, our findings are consistent with other studies in patients with preserved EF that suggest that individual variables demonstrate poor ability to represent invasive pressures, and advocate a multi-parametric approach to filling pressure assessment.6 In a recent EACVI survey to study adoption of the ASE/EACVI guidelines in routine practice, LASr was chosen by 34% of respondents as a method of choice in challenging diagnostic scenarios.19 Additionally, LASr has been incorporated in a revised algorithm in the recent EACVI recommendations for multimodality imaging in HFpEF.9 LA phasic function can be evaluated during the reservoir, conduit, or contractile phase and changes in strain has been shown to be independent of LA volume in HFpEF.20 We chose to evaluate deformation during the reservoir phase, LASr, based on high feasibility, wider utilization, and greater agreement with worsening diastolic dysfunction when compared with other LA phasic strain measures.7 LASr is reduced in diastolic dysfunction, demonstrates better agreement with invasive LV filling pressure when compared with conventional algorithms when EF is preserved,21 and accurately grades diastolic dysfunction severity.7 Further, LASr has previously been shown to correlate well with elevated filling pressure in HF during rest,22 and has demonstrated strong ability to discern disproportional pressure rise during exercise.23 Our data suggest that incorporating LASr into the current diastolic algorithm further enhances its feasibility, accuracy, and diagnostic performance and, hence, may be a promising clinical tool. Enhanced accuracy seen in models considering LASr in this study was driven predominantly by improved specificity of the revised approaches to determine elevated filling pressures. The stronger ability of these modified echocardiographic approaches to ‘rule-in’ diastolic dysfunction by better identification of those with non-elevated filling pressure may further enhance utility to screen and triage patients with unexplained breathlessness. Given that LA filling corresponds with LV long-axis shortening during systole, further studies are necessary to establish additional information LASr provides over what LV longitudinal strain already offers.Studies showcasing modest ASE/EACVI algorithm discriminatory performance suggest that complementary scores and/or more advanced investigative approaches may improve diagnostic accuracy and reduce indeterminate classification.8 our data add that LASr may also offer additional value when complementing the 2016 ASE/EACVI recommendation as suggested recently by the EACVI recommendations for multimodality imaging in HFpEF.9Our study has important clinical implications in the management of unexplained dyspnoea, as accurate identification of the underlying cause has direct consequences on choice of therapy. This is even more relevant in the setting of normal EF, where focused assessment of LV size and systolic function may not suitably explain the patient’s symptoms. While the accuracy of LA pump strain to identify normal filling pressure in preserved EF has recently been suggested,r. Further validation of these findings is necessary in additional large-sample, multicentre studies. Our study cohort comprised patients with unexplained breathlessness referred to two tertiary-care centres and may not reflect a general HFpEF population. Nevertheless, the study presents a real-world scenario in PH specialist centres where distinction between HFpEF and pulmonary disorders is often challenging and stronger screening algorithms to rule-in diastolic dysfunction are needed. We employed fluid-filled catheters to obtain PCWP measurements rather than high-fidelity microcatheters and this may be considered a limitation. Inter-operator and inter-evaluator variability may be considered a limitation in our study, given that we did not employ a core-lab approach to echocardiographic image analysis. However, a standard international acquisition and analysis protocol was followed by two experienced echocardiographers with over 15 years’ experience. Further, we evaluated the contribution of LASr to diastolic assessment in the same cohort rather than employ a retrospective derivation and independent prospective validation cohort, which may have strengthened our study design. Absence of information on LA pump strain in this cohort may also be considered a limitation, given that high LA pump strain has demonstrated strong ability to identify patients with normal filling pressure when EF is preserved.8 However, we chose to focus on LASr which is more robust, and in keeping with the recent expert consensus algorithm.9 Finally, diastolic stress tests were not performed in all our patients. Although stress testing may have improved the diagnostic accuracy of the ASE/EACVI algorithm, this was not the aim of this study.Important limitations of the current study are the low proportion of patients with elevated PCWP and inclusion of patients with pulmonary parenchymal or vascular disorders. This may bias our results, which include sensitivity analysis in the proposed models incorporating LASr into the 2016 ASE/EACVI recommendation-based assessment improves detection of elevated filling pressure.In the setting of preserved EF, incorporation of LASEuropean Heart Journal - Cardiovascular Imaging online.A.V. was supported by grants from the Swedish Association for Pulmonary Hypertension; L.H.L. was supported by grants from the Swedish Research Council (2013-23897-104604-23 and 523-2014-2336), Swedish Heart Lung Foundation (20100419 and 20120321), Stockholm County Council (20110120 and 20140220), and Swedish Society of Medicine (174111 and 504881). P.L. was supported by grants from The Swedish Heart and Lung foundation (20160787 and 20200160) and the Swedish Research Council (2019-01338).jeac036_Supplementary_DataClick here for additional data file.


Despite all the important advances in its diagnosis and treatment, acute myocardial infarction (AMI) is still one of the most prominent causes of morbidity and mortality worldwide. Early identification of patients at high risk of poor outcomes through the measurement of various biomarker concentrations might contribute to more accurate risk stratification and help to guide more individualized therapeutic strategies, thus improving prognoses. The aim of this article is to provide an overview of the role and applications of cardiac biomarkers in risk stratification and prognostic assessment for patients with myocardial infarction. Although there is no ideal biomarker that can provide prognostic information for risk assessment in patients with AMI, the results obtained in recent years are promising. Several novel biomarkers related to the pathophysiological processes found in patients with myocardial infarction, such as inflammation, neurohormonal activation, myocardial stress, myocardial necrosis, cardiac remodeling and vasoactive processes, have been identified; they may bring additional value for AMI prognosis when included in multi-biomarker strategies. Furthermore, the use of artificial intelligence algorithms for risk stratification and prognostic assessment in these patients may have an extremely important role in improving outcomes. Cardiovascular diseases are the leading cause of morbidity and mortality worldwide, with an estimated 17.9 million deaths annually . MyocardAn ideal biomarker should have a high sensitivity and specificity, as well as several clinical and assay-related characteristics, such as a good cost-effectiveness ratio, short processing time and high precision. These characteristics ensure a straightforward assay process to guide therapy and predict the prognosis of patients. Currently, there is no single ideal biomarker that can improve risk prediction for patients with AMI; it is a considerable challenge for clinicians to discover an ideal biomarker. Thus, in order to identify novel predictive biomarkers, researchers have used proteomic technologies. Proteomics have been used to highlight the significant alterations in the cardiac proteome following an MI. A proteomic study of unstable plaques also revealed new evidence about the pathologic processes of plaque rupture . This coAlthough there is no ideal biomarker that can provide prognostic information for risk assessment of patients with AMI, the results from recent years are promising ,13,14. FThe aim of this article is to provide an overview of the role and applications of cardiac biomarkers in risk stratification and prognostic assessment for patients with myocardial infarction. Additionally, this article reviews the classic biomarkers that have already demonstrated their prognostic role in patients with acute myocardial infarction, as well as new biomarkers that may have potential clinical value in the future.C-reactive protein (CRP) has become one of the most studied biomarkers of inflammation due to the fact that atherothrombosis represents a large majority of acute myocardial infarctions, and CRP is strongly associated with this type of pathogenesis. As an acute phase protein, CRP levels are elevated in inflammatory or infectious processes due to the liver’s response to high concentrations of plasma cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). Increased levels of CRP have been reported as an independent predictive biomarker for cardiac or noncardiac death and even for recurrent nonfatal events, with detection of CRP at 4–6 h after the occurrence of AMI and a peak level of CRP after about 50 h . CRP is Fibrinogen (FIB) was one of the first clotting factors to be identified. It was first studied in the 19th century and represents an acute phase protein produced in the liver. Its effects are multiple, including on platelet aggregation, endothelial lesions, plasma viscosity and the fibrinolysis system, and it is therefore directly implicated in the formation of thrombi ,23. Thro2), current smoking and severe coronary lesions [Interleukin-6 (IL-6) is one of the most important cytokines. It is produced by T-cells and macrophages in response to a trauma or to an infection and involves hepatic CRP liberation in the second stage of the process . It may  lesions . Ridker  lesions ,34. In a lesions .p < 0.05) compared to those with stable or without angina, especially in those with an electrically ischemic modification (p < 0.05), its levels being steadily elevated in relation to the degree of coronary artery disease (CAD) [Interleukin-37 (IL-37) is an interleukin-1 (IL-1) family cytokine found in low levels in multiple locations, such as the brain, heart, colon, prostate and tonsils, and even in epithelial cells, keratinocytes, plasma cells, monocytes and macrophages . Being ase (CAD) . In addise (CAD)  illustrase (CAD) . It has p < 0.001), even if its levels were greater in this group of patients despite not being associated with long-term outcomes or in-hospital mortality [Procalcitonin (PCT) is an inactive precursor of calcitonin implicated in calcium homeostasis. Strong bacterial infections, major surgery and burns, various traumas and cardiogenic shock are some of the situations where serum PCT levels are greatly increased . In receortality . In addiortality .p < 0.001) and death (p < 0.001) but also for stroke and myocardial infarction [B-type natriuretic peptide (BNP) is a hormone produced as a consequence of ventricular dysfunction. Being secreted by cardiac cells, its roles include inhibition of the renin-angiotensin-aldosterone system, natriuresis and vasodilatation . Recentlfarction . Moreovefarction . Recentlfarction . Kazuhirfarction . Furtherfarction .p = 0.024) [Adrenomedullin (ADM), initially isolated from a pheochromocytoma tissue, is a ubiquitous peptide present in physiological conditions in vascular, renal, adipose, pulmonary and cardiac tissue. Increased plasma levels in patients with different diseases, such as congestive heart failure, hypertension, diabetes mellitus and myocardial infarction, were stimulated by volume overload ,53. Give= 0.024) .p = 0.0002). Furthermore, in patients older than 60 years old who were associated with an LVEF lower than 40%, this turned out to have a stronger prognostic value. Additionally, a positive correlation was found between NT-proBNP and the GRACE score  [p = 0.008), an early assessment of the amount of the cardiac damage being an essential instrument for post-STEMI risk stratification [p = 0.031), along with female sex, QS waves on electrocardiogram (ECG) and wall motion dysfunction.N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a prohormone released by cardiac cells in response to either myocardial stretching or an AMI. Despite the properties of BNP, NT-proBNP is associated with stability and a longer half-life time . Moreove 0,0001) . In a re 0,0001) . The secfication . Celebi fication  showed tfication  revealedp = 0.022), being even better than the peak cardiac troponin I levels studied under the same conditions. Copeptin could encourage more aggressive treatment [p < 0.001 for each) [p = 0.024). Recently, copeptin was found to be an independent predictive factor for total mortality but also a marker for general vulnerability, being influenced by the presence of HF, diabetes mellitus type 2, female sex and previous MI [r = −0.45 at the early stage; r = −0.662 at 6 months) [Copeptin is one of the biomarkers used in cardiovascular disease, as the C-terminal part of the pro-arginine vasopressin is secreted in equimolar quantities with it, and it also presents great stability in biological samples . In the reatment . Furtheror each) . In a stor each)  that incvious MI . In prev months) . In addi months) .p = 0.008), MPV being measured upon admission and 2–3 days after. In a study that enrolled 1094 patients with ACS, Chang et al. [p = 0.002), high levels of MPV being associated with MACEs . In particular, a retrospective study showed that high levels of MPV (MPV ≥ 9.0 fl) in patients with NSTEMI were associated with a substantial CAD (p = 0.005), defined as ≥ 1 major coronary artery stenosis (≥70%) [p < 0.01). Furthermore, greater mean platelet volume was identified as a predictor of death in patients with AMI throughout their hospitalization [p < 0.001). Recently, a meta-analysis that grouped 21 studies concluded that a higher MPV is associated with reduced post-intervention coronary flow  [Platelets (PLTs) are small and anucleated cells that are derived from megakaryocytes secondarily to a maturation process that takes place in bone morrow. They are then re-leased into the bloodstream, where they have a limited lifespan of 5–7 days. They are multifunctional cells that play an essential role in primary hemostasis and thrombosis, addressing any hemorrhagic situations that appear at the level of the vascular endothelium or tissue as the result of an injury ,71. Furtg et al.  found ths (≥70%) . In conts (≥70%)  found nolization . The prilization  proved t 0.0001) . Moreove 0.0001) ,82.p = 0.01) together with peak levels of creatine kinase (CK) (p = 0.0008) as a long-term predictor of impaired LV systolic function < 50% in STEMI patients with preserved systolic function at onset and single-vessel coronary disease [p < 0.001) and peak post-procedural hs-cTnT levels  were independently correlated with all-cause mortality over up to 3 years of follow-up [Troponins   are structure proteins that are implicated in actin–myosin interaction. They are produced and released from cardiomyocytes in response to increased stretch or necrosis. Hence, cTnT and cTnI, which are known as cardiac-specific troponins, have been proven to have and important role as a diagnostic marker for cardiac injury and AMI ,83. Afte disease . Along t disease . However disease . Wanamak disease ,89. In aollow-up . Additioollow-up  has provollow-up ,92. In aollow-up ,94.p = 0.001) [Creatine kinase-MB (CK-MB), an isoenzyme of enzyme CK located mostly in cardiac cells, and in low levels in skeletal muscle, is released into circulation within 4–6 h after a cardiac injury, reaching a peak at 24 h and returning to normal after 48–72 h. In a Dutch study that enrolled 1360 STEMI subjects with a median follow-up period of 6.7 years, heart failure occurred in 85 patients (6.3%). Peak creatinine-kinase values, together with a left anterior descending artery culprit lesion, have been found to be an important predictor of heart failure development . In the = 0.001) . In addi= 0.001)  proved t= 0.001) . Peak CK= 0.001) .p < 0.0001) and functioned as a predictor for MACEs, cardiovascular mortality and all-cause mortality in AMI patients within 4 years of follow-up. In addition, elevated levels of cysC measured at any stage within the first year after an ACS positively correlated with the composite endpoint  (p = 0.006). Further, the 12th to 14th day measurements demonstrate an important predictive role regarding adverse cardiovascular outcomes within 3 years of follow-up [p < 0.05) in acute coronary syndrome patients [Cystatin C (cysC) is a pleiotropic cysteine protease inhibitor that regulates cathepsins S and K in human vascular pathology, being a part of the catabolism processes of most proteins in nucleated cells. In normal conditions, cysC is an indicator of renal function, with greater sensitivity than serum creatinine for incipient stages of renal function. It could also be present in cardiomyocytes, showing an important increase in a hypoxic scenario ,105,106.ollow-up ,112. On patients ,115,116.patients  includedpatients . In addipatients .Heart-type fatty acid binding protein (H-FABP) is a cytoplasmatic protein involved in the metabolism of fatty acid in the myocardium. Its level increases promptly (< one hour) during a myocardial injury, with a peak at 4–6 h and return to baseline after 24 h . Therefop < 0.001), defined as HF, recurrent ischemia or in-hospital death, at hospital admission or at 30-days follow-up, being positively correlated with the thrombolysis in myocardial infarction (TIMI) risk score. A recent study has postulated that endothelial dysfunction and inflammation mediated by high concentrations of endocan could generate poor cardiomyocyte microvascular perfusion and, thus, create incomplete ST-segment resolution (STR) and extensive myocardial damage [The endothelial cell-specific molecule-1 (ESM-1), or endocan, is a soluble proteoglycan produced by human vascular endothelial cells. It is implicated in numerous processes, such as cell adhesion, migration, neovascularization and proliferation. Its secretion is upregulated by a series of proinflammatory cytokines , suggesting that it plays a key role in inflammation and endothelial dysfunction in various vascular disorders  ,128,129.l damage . Cimen el damage  followedl damage . Dogdus l damage  enrolledp < 0.001) in AMI patients. A value greater than 2 for this ratio is an indicator of total occlusion of the culprit lesion. Furthermore, the De-Ritis ratio has predictive value in association with NT-proBNP, troponin T and CK [Aspartate transaminase (AST) is a liver transaminase and is especially derived from its levels at this location. It can also be found in other locations, such as the heart, muscles and red blood cells. Therefore, this biomarker presents an imperfection with regard to its liver function specificity . Data haT and CK ,139.Myoglobin, a hemoprotein expressed in the cytoplasm of striated muscle cells , has long been used as a biomarker in the early detection of acute coronary syndrome due to its rapid release into circulation (within the first 30 min). Unfortunately, due to its limited cardiac selectivity, attention has shifted to troponins ,140. FurCardiac myosin-binding protein C (cMyC) is a structural cardiac protein that has fivefold greater cytoplasmic concentrations than cardiac troponins. It peaks in plasma early in the event of an ACS, showing the same diagnostic performance as cTn ,145. AccIschemic-modified albumin (IMA) is a type of human serum albumin. It is very sensitive and identifiable in the early reversible stage of ACS, in which the N-terminal amino acids have been altered by pathological conditions, such as hypoxia, acidosis, free radical damage and energy-dependent membrane disruption . Ding anLactate dehydrogenase (LDH) is an enzyme that catalyzes the conversion of lactate to pyruvate and back the conversion of NAD+ to NADH and back. According to a recent prospective study that looked at the link between LDH and left ventricular function after MI, this biomarker is an independent positive predictor of unfavorable remodeling, which is a leading cause of heart failure, and a negative marker of reversal remodeling .p = 0.003). Additionally, they proved that there is a positive correlation between the number of vessels affected and Gal3 levels (p = 0.04) [p = 0.02) [p < 0.001) [Galectin-3 , part of the galectin family, is a glycoprotein that binds at a variety of locations where it can be found, such as the spleen, stomach, heart, liver, pancreas and uterus, as well as being expressed by all type of immune cells, epithelial cells and endothelial cells ,151,152. = 0.04) . There a = 0.04) ,158,159. = 0.04) ,160. In  = 0.04)  demonstr = 0.04) . The rol = 0.04)  but, in  = 0.04) . In addi = 0.04) . George  = 0.02) . In the < 0.001) . In anot< 0.001) .p = 0.001). Apart from this, notable MACE values  were greater in the same group [p < 0.001) [Soluble suppression of tumorigenicity 2 (sST2) is an isoform-type of the protein ST2. It is implicated in the homeostasis and pathogenesis of multiple inflammatory and cardiac pathologies and autoimmune diseases. It is especially expressed in those processes that imply fibrosis, remodeling or tissue lesions . Therefome group . Other ime group . Aleksovme group  measuredme group . Althoug< 0.001) . In a pr< 0.001) . Additio< 0.001) . A serie< 0.001) ,175,176.The transforming growth factor-beta (TGF-beta) family of proteins includes a subfamily of proteins known as growth differentiation factors (GDFs). GDF-15 is increased in response to cardiac damage and the inflammatory process, thereby increasing the risk of an elevated cardiovascular event . In the Syndecan-1 (Sdc1) is a surface protein that is a component of the endothelial glycocalyx (eGC), a complex of transmembrane proteins that are found on the endothelial surface of blood vessels. Damaged eGC-soluble sdc1 that can be used as an indicator is produced during shedding. An Sdc1 level greater than 148 ng/mL was 14 times more likely to lead to an ACS diagnosis (95% CI: 1.8 to 102) . In termLIPCAR, a long noncoding RNA (lncRNA), is located in the nucleus and cytoplasm. It lacks the capacity to code for proteins, but it may still control gene expression through epigenetics and may serve a variety of purposes inside the cell. According to a cross-sectional study at Shanghai Gong Hospital’s Department of Cardiology, LIPCAR levels were higher in HF patients following an AMI than in patients without HF, and the test had a high positive predictive value for the diagnosis of HF. The findings suggest that LIPCAR may be a biomarker of early HF following AMI . In patiFive atrial extracellular matrix (ECM) member proteins form the thrombospondin family, with thrombospondin-1 (TSP-1) being the best known due to its role in inflammation and fibrogenesis in several illnesses, including liver fibrosis, diabetes, various cancers and cardiovascular conditions . TSP-1, Uric acid (UA) is the final degradation product of purine nucleotides from endogenous (cellular nucleoproteins) and exogenous origins  . In the A powerful vasoconstrictor with adverse cardiac inotropic and chronotropic effects, neuropeptide Y (NPY) is a peptide co-localized and co-released with NA from sympathetic nerve terminals, particularly during situations of sympathetic hyperactivity, such as myocardial infarction ,206. AccA member of the epidermal growth factor family, neuregulin-1 (NRG-1) is crucial for the development of cardiomyocytes and cardiac regeneration. There are six isoforms, and each one has an EGF-like domain that is both required and sufficient to activate ErbB receptors and, thus, exerts essential biological activities . Prior sMicroRNAs (miRNAs) are small (∼22 nucleotides), single-stranded fractions of non-coding ribonucleic acids that act as micro-regulators of gene expression. They are present in a very stable state in whole blood, serum, plasma, urine and other bodily fluids. They are ideal as diagnostic or prognostic biomarkers because their levels in the blood depend on the many illnesses that they are related to ,225,226.Studies relating prognostic biomarkers in patients with acute myocardial infarction are presented in Despite all the important advances in the diagnosis and treatment of patients with myocardial infarction, this still remains one of the most important causes of morbidity and mortality worldwide. In recent years, a growing number of biomarkers have been studied and proposed as potentially useful for patients with myocardial infarction, but none of them possess the characteristics of an ideal biomarker that could provide prognostic information for risk assessment of patients with AMI. However, we consider that the future holds great promise in terms of the opening of new directions of research for the identification of the best prognostic AMI biomarkers that would considerably improve the short- and long-term outcomes of these patients. Furthermore, the use of artificial intelligence algorithms for risk stratification and prognostic assessment in these patients may have an extremely important role in improving outcomes.Biomarkers could become a useful tool for prognostic assessment of patients with myocardial infarction. Furthermore, biomarker research in myocardial infarction has advanced immensely over the last years, especially as a result of understanding the other processes involved in the pathophysiology of myocardial infarction, such as inflammation, myocardial stress and neurohormonal activation. Nevertheless, in the absence of randomized trials evaluating the relationship between these biomarkers and their predictive usefulness in individuals who have had an AMI, their use awaits further validation and research. Furthermore, novel biomarkers might be able to guide more individualized therapeutic strategies in order to improve prognoses.


Incomplete reperfusion after mechanical thrombectomy (MT) is associated with a poor outcome. Rescue therapy would potentially benefit some patients with an expanded treatment in cerebral ischemia score (eTICI) 2b50/2b67 reperfusion but also harbors increased risks. The relative benefits of eTICI 2c/3 over eTICI 2b50/67 in clinically important subpopulations were analyzed.i) was analyzed.Retrospective analysis of our institutional database for all patients with occlusion of the intracranial internal carotid artery (ICA) or the M1/M2 segment undergoing MT and final reperfusion of ≥eTICI 2b50 (903 patients). The heterogeneity in subgroups of different time metrics, age, National Institutes of Health Stroke Scale (NIHSS), number of retrieval attempts, Alberta Stroke Programme Early CT Score (ASPECTS) and site of occlusion using interaction terms . An eTICI 2c/3 had less consistent association with mRS ≤2 in older patients  and patients with either lower NIHSS (≤9) or very high NIHSS . Regarding occlusion sites, the beneficial effect of eTICI 2c/3 was absent for occlusions in the M2 segments .The presence of eTICI 2c/3 was associated with better outcomes in most subgroups. Time metrics showed no interaction of eTICI 2c/3 over eTICI 2b50/2b67 and clinical outcomes  contains supplementary material, which is available to authorized users. The association of better clinical outcomes and reduced long-term mortality with increased reperfusion quality of mechanical thrombectomy is well established –8. A modIt remains less clear which patients with intraprocedural eTICI 2b50/2b67 reperfusion would benefit from rescue therapy and in which patients additional retrieval attempts may be futile/unnecessary and expose patients to unnecessary risks . Recent With the intention to explore a potential heterogeneity of the relative benefits of eTICI 2c/3 over eTICI 2b50/2b67, we analyzed outcome differences across different reperfusion grades in clinically important subpopulations.st January 2010 and 31st December 2018. Patients with incomplete/insufficient angiographic documentation of preinterventional and postinterventional digital subtraction angiography (DSA) runs as well as incomplete clinical history were excluded  or the M1/M2 segment, undergoing endovascular stroke treatment and final reperfusion degree of ≥50% (≥eTICI 2b50) between 1The thrombolysis in cerebral infarction (TICI) scale visually estimates the grade of reperfusion of the initially hypoperfused territory (target downstream territory [TDT]), represented as restored antegrade capillary blush on DSA . To assen = 761/903) were evaluated independently by core laboratory judication in the same fashion.In the first step, three neuroradiologists independently evaluated the eTICI scores for 142 randomly selected patients based on preprocedural and postprocedural DSA runs, with both an anterior-posterior and a lateral projection. They were blinded to other clinical, imaging, and outcome data. Since good interrater reliability was achieved, the remaining cases  scale: 0—No collaterals visible to ischemic site, 1—Slow collaterals to the periphery of ischemic site, with persistence of some of the defect, 2—Rapid collaterals to the periphery of ischemic site, with persistence of some of the defect, and to only a portion of the ischemic territory, 3—Collaterals with slow but complete angiographic blood flow of the ischemic bed by the late venous phase, 4—Complete and rapid collateral blood flow to the vascular bed in the entire ischemic territory by retrograde perfusion .n (%) if not otherwise specified.Baseline and outcome parameters between the groups were compared using the Kruskal-Wallis test for continuous variables or the Fisher’s exact test for categorical variables. Data are displayed as median (interquartile range [IQR]) and Interrater reliability was assessed using Krippendorff’s alpha for multiple raters. Krippendorff’s alpha is a coefficient representing the interrater reliability for any number of raters and any kind of variables. Values were interpreted as follows: 0 = poor; 0.01–0.20 = slight; 0.21–0.40 = fair; 0.41–0.60 = moderate; 0.61–0.80 = substantial and 0.81–1.0 = almost perfect agreement.The distribution of clinical outcomes (mRS at 90 days after the intervention) for each eTICI was depicted graphically. Furthermore, binary logistic regression modeling was performed to assess the association of eTICI and clinical outcome (dichotomized into mRS ≤2 = good outcome versus mRS >2 = poor outcome ) and to The cases were then grouped into eTICI 2b50/2b67 and eTICI 2c/3. A multiplicative interaction term (eTICI*variable) was used to test for interaction with the following variables: continuous time metrics , age on admission, NIHSS on admission, number of retrieval attempts, ASPECTS, ASITN/SIR DSA collateral score and site of occlusion.To assess heterogeneity, subgroups were defined based on their quartiles for time metrics, age, and NIHSS; for ASPECTS as 0–4, 5–7, and 8–10 ; for colp-value of <0.05 was considered statistically significant.All statistical analyses were conducted using R  . A two-tp = 0.03) and a lower number of retrieval attempts . Patients with NIHSS ≤9 presented with better collaterals  than patients with NIHSS 10–19  and consequently, patients with NIHSS ≥20 had worse collaterals  than patients with NIHSS 10–19 (p < 0.001) (Suppl. Table I). Except for a higher proportion of current/history of smoking in the eTICI 2b67 population, the groups were well balanced regarding risk factors and stroke etiology.A total of 903 patients with occlusion of the intracranial ICA or M1/M2 segments  were included. Baseline characteristics are shown in Table Higher degrees of eTICI were associated with mRS 90-day ≤2 .p for interaction: time from onset to reperfusion p = 0.77, time from groin puncture to reperfusion p = 0.65, time from onset to groin puncture p = 0.63). The adjusted odds ratios (aOR) for mRS 90-day ≤2 stratified by dichotomized eTICI scores slightly changed between different quartiles but showed no clear trend  over time courses stratified by dichotomized eTICI scores are shown in Fig. We also observed a decreasing proportion of patients with eTICI 2c/3 reperfusion with increasing time metrics, probably most striking in the subgroups of the puncture to reperfusion time: 185/264 (70.1%) patients achieved eTICI 2c/3 in the group with ≤28 min, 131/215 (60.9%) patients in the group with 29–40 min, 120/232 (51.7%) patients in the group with 41–65 min and only 77/192 (40.1%) patients in the group with >65 min.p for interaction = 0.08), adjusted odds ratios for each quartile were as follows . These findings did not change substantially in a subanalysis including only patients with prestroke mRS ≤2 : ≤62 years aOR 2.06 (95% CI 1–4.23), 63–73 years aOR 2.24 (95% CI 1.11–4.59), 74–82 years aOR 1.95 (95% CI 1.01–3.84), and >82 years aOR 0.69 (95% CI 0.29–1.65).Older age groups showed a trend towards decreasing beneficial effect of eTICI 2c/3 over eTICI 2b50/2b67 (p for interaction = 0.84) and no statistically significant interaction for NIHSS on admission when quartiles were handled as independent groups (p for interaction = 0.37). In patients with low NIHSS  and patients with high NIHSS  however, eTICI 2c/3 had less impact on good clinical outcome as opposed to the middle groups . In a further subgroup analysis of the low NIHSS group, patients with NIHSS ≤5 benefited less from eTICI 2c/3  than patients with NIHSS 6–9 .There was no trend in change of beneficial effect of eTICI 2c/3 in quartiles of the number of retrieval attempts (p for interaction 0.08).We found an increasing beneficial effect of eTICI 2c/3 with decreasing collateral scores .There was no heterogeneity regarding the association of eTICI 2c/3 with good clinical outcomes across ASPECTS  over age Fig.  and ASPEp for interaction vs. other occlusion sites pooled = 0.018).We found beneficial effects of eTICI 2c/3 in occlusions of the intracranial ICA/T or L occlusions  and of the M1 segments ; however, this association was absent in patients with M2 occlusions  better eTICI scores were associated with better clinical outcomes across several subgroups, including a large range of early ischemic changes and various time courses, and 2) a decreasing beneficial effect of eTICI 2c/3 over eTICI 2b50/2b67 was only found in older patient groups, more distal occlusions and patients with either low or very high NIHSS.In line with previous work , 10, we We did not find interactions of various time courses with clinical outcome after 90 days, contradicting the results of the study of Kitano et al. . They foWe found a trend of decreasing beneficial effect of complete recanalization in older patient groups, with the biggest leap being in the group with patients older than 82 years. This phenomenon is well known and probably relies on multiple factors, such as higher prevalence of comorbidities, higher rates of polypharmacy, and reduced neuronal plasticity –24. MoreAnother interesting finding is that patients with either low NIHSS (≤9) or very high NIHSS (>19) did not benefit from eTICI 2c/3 as much as the group with NIHSS 10–19. A possible explanation for this could be that patients presenting with low NIHSS were more likely to have good to excellent collateral status and patients presenting with very high NIHSS were more likely to have poor collateral status. Previous studies showed the association of adequate collaterals and good tissue outcome , 27 and While a beneficial effect of eTICI 2c/3 on the mRS at 90 days was present in ICA/T and M1 occlusions, it was absent in M2 occlusions. Obviously, eTICI 2b50/2b67 perfusion deficits after M2 occlusions are significantly smaller compared to the range of possible perfusion deficits in eTICI 2b50/2b67 reperfusion after e.g. M1 occlusions. Other possible explanations are different collateral situations in medium vessel occlusions and smaller amounts of affected brain tissue and therefore having a lower probability to affect more eloquent brain areas. In this sense, reliable measurement of the volume of remaining hypoperfused tissue during mechanical thrombectomy (e.g. with flat-panel CT perfusion) could help in deciding whether to extend or discontinue the procedure.Regarding extended mechanical thrombectomy for improving eTICI 2b50/2b67 to eTICI 2c/3, it is still not possible to draw clear boundaries for proper patient selection. In an individual case-based decision the operator may weigh in the likelihood of the improvement being clinically futile, which seems to occur more often in older patients, M2 occlusions and patients with either low or very high NIHSS.The retrospective analysis of data from a single center implicates limitations of our study and generalizability of our results on other cohorts has to be validated. Furthermore, we found shorter time from symptom onset to groin puncture and lower number of retrieval attempts in patients with higher degrees of reperfusion, possibly biasing our findings. While we have corrected for these confounders in all presented logistic regression analyses, there was high collinearity between these variables and the possibility of residual and hidden confounding remains.The results of our study should be interpreted with caution. It is not clear whether secondary established eTICI 2c/3  over eTICI 2b50/2b67 has the same beneficial effects as first pass eTICI 2c/3, but recent reports seem promising , 29. On A particular strength of our study is the consistent core laboratory judication of the eTICI scores of our large sample size.The beneficial effect of eTICI 2c/3 over eTICI 2b50/2b67 was stable over various time metrics. It only decreased in older patient groups, M2 occlusions, patients with either low or very high NIHSS and patients with good to excellent collaterals. Improving eTICI 2b50/2b67 to eTICI 2c/3 in those subgroups may be more often futile, which should be acknowledged when making individualized decisions regarding potential improvements from eTICI 2b50/2b67 to eTICI 2c/3.Supplementary Table I


Paciente do sexo masculino, 72 anos, com história pregressa de hipertensão arterial, diabetes não insulino-dependente, tabagismo ativo e angina crônica estável . Apresentava também história de etilismo, calcificação pancreática e litíase renal, sem história de Câncer, Sepse ou Tuberculose que justificassem essas calcificações difusas.Apresentou-se no ambulatório de cardiologia com queixa de angina e dispneia classe II da New York Heart Association (NYHA). O eletrocardiograma (ECG) mostrava ritmo sinusal e sugeria hipertrofia ventricular esquerda (HVE) sem sinais de isquemia.As imagens do ecocardiograma foram subótimas devido à janela acústica ruim, mas mostraram disfunção sistólica ventricular esquerda leve com disfunção diastólica grave , HVE e hipertensão pulmonar grave (pressão sistólica da artéria pulmonar 78 mmHg) com diâmetros de ventrículo direito normais e função sistólica. Além disso, múltiplas imagens hiperecogênicas com sombras acústicas foram observadas dentro do miocárdio, infiltrando predominantemente o septo interventricular.Foi admitido no Hospital por sinais de insuficiência cardíaca aguda, com ortopneia, estertores pulmonares bilaterais e edema periférico bilateral, sem necessidade de oxigênio suplementar. O laboratório de soro demonstrou depuração de creatinina normal (>60 mg/ml), alto N terminal pró-peptídeo natriurético cerebral (NT-pro-BNP) e níveis séricos de troponina . Os parâmetros séricos fosfocálcicos estavam dentro da faixa normal. Notavelmente, uma equipe multidisciplinar avaliou o paciente, incluindo nefrologista, endocrinologista e cardiologistas clínicos.Devido aos achados anormais e subótimos no ecocardiograma, foi realizada uma angiotomografia computadorizada (ATC), que foi positiva para extensos depósitos de cálcio intramiocárdico (escore de Agatston miocárdico de 112.929) com distribuição helicoidal que se assemelhava ao padrão das fibras miocárdicas de Torrent Guasp   . O escoUma Ressonância Magnética Cardíaca (RMC) com contraste foi realizada para identificar melhor as características do tecido. Mostrou função sistólica do ventrículo esquerdo normal (fração de ejeção do ventrículo esquerdo de 54%), com aumento da massa miocárdica e hipocinesia basal e septal   . O ventO paciente foi tratado com diuréticos de alça endovenosos e recebeu alta com melhora dos sintomas. A cintilografia com pirofosfato de 99m-tecnécio foi realizada durante o seguimento, negativa para amiloidose cardíaca. Além disso, para obtenção de material para amostragem histológica, foi realizada biópsia endomiocárdica, mostrando achados histológicos normais.1 Além disso, as calcificações miocárdicas geralmente representam as sequelas de dano tecidual local e necrose celular e estão associadas a um risco aumentado de eventos cardiovasculares (arritmias ventriculares e disfunção sistólica/diastólica levando à insuficiência cardíaca).2 O paciente apresentava história de hipertensão, diabetes e doença arterial coronariana. Frequentemente, a hipertensão não é suficiente para explicar completamente a calcificação miocárdica, sendo comumente associada à doença renal crônica (DRC), onde a calcificação está associada a um distúrbio fosfocálcico.3 Além disso, o diabetes produz um distúrbio inflamatório sistêmico que pode contribuir para um aumento da calcificação coronariana.4 Além disso, a doença arterial coronariana é uma causa muito comum de calcificação miocárdica distrófica.1 A cardiomiopatia hipertensiva ou infiltrativa não pode ser totalmente excluída, apesar dos achados de TC e RMC.Os depósitos de calcificações miocárdicas podem estar presentes em múltiplos cenários fisiopatológicos, como calcificações distróficas por doença cardíaca de base e doenças sistêmicas idiopáticas ou metastáticas.6Esses padrões de calcificação podem ser diagnosticados com múltiplas modalidades de imagem, sendo a ATC a modalidade padrão-ouro para identificação e caracterização de calcificações miocárdicas. De fato, diferentemente do padrão de calcificação bem definido nas patologias intrínsecas do miocárdio, a infiltração de cálcio por doenças sistêmicas geralmente tem um padrão difuso. Além disso, a RMC pode fornecer mais caracterização tecidual, sugerindo calcificação miocárdica em áreas intramiocárdicas de baixo sinal e miocárdio cicatrizado ao redor de calcificações por imagens de LGE.8 A pesquisa mostrou que essa distribuição de dupla hélice raramente é encontrada em modalidades de imagem não invasivas, tornando este caso uma representação viva do padrão Torrent Guasp.A Teoria de Torrent Guasp foi originalmente descrita macroscopicamente em pacientes post mortem, em que as fibras miocárdicas se estruturavam como uma faixa estendida desde a raiz da artéria pulmonar até a raiz da aorta circunscrevendo os dois ventrículos em uma fibra com padrão de dupla hélice. Esse padrão é responsável pelo funcionamento normal e efetivo do coração, explicando a variação do volume intraventricular dentro de cada batimento.Apresenta-se um caso de insuficiência cardíaca com fração de ejeção preservada com calcificação miocárdica difusa e atípica seguindo a distribuição Torrent Guasp. Múltiplas causas  podem contribuir para a origem da calcificação, a que em última análise está associada a um pior desfecho clínico. Diversas modalidades de imagem são fundamentais para alcançar um diagnóstico específico e, eventualmente, um tratamento específico. 72-year-old male patient with a past medical history of arterial hypertension, non-insulin-dependent diabetes, active tobacco consumption and chronic stable angina . He also had a history of alcohol consumption, pancreatic calcification and renal lithiasis, without a history of Cancer, Sepsis or Tuberculosis to justify these diffuse calcifications.He presented to the outpatient cardiology clinic complaining of angina and dyspnea New York Heart Association (NYHA) class II. His electrocardiogram (ECG) showed sinus rhythm and suggested left ventricular hypertrophy (LVH) without signs of ischemia.The echocardiogram images were suboptimal due to poor acoustic window but showed mild left ventricular systolic dysfunction with severe diastolic dysfunction , LVH and severe pulmonary hypertension (systolic pulmonary artery pressure 78 mmHg) with normal right ventricle diameters and systolic function. Furthermore, multiple hyperechogenic images with acoustic shadows were seen within the myocardium, predominantly infiltrating the interventricular septum.He was admitted to the Hospital due to signs of acute heart failure, with orthopnea, bilateral pulmonary rales, and bilateral peripheral edema, without the need for supplementary oxygen. The serum laboratory demonstrated normal creatinine clearance (>60 mg/ml), high N terminal pro-brain natriuretic peptide (NT-pro-BNP) and troponin serum levels . Serum phospho-calcic parameters were within the normal range. Notably, a multidisciplinary team evaluated the patient, including a nephrologist, endocrinologist, and clinical cardiologists.Due to the abnormal and suboptimal findings in the echocardiogram, a computed tomography angiography (CTA) was performed, which was positive for extensive intramyocardial calcium deposits  with a helicoid distribution that resembled Torrent Guasp’s myocardial fibers pattern   . The CoA Cardiac Magnetic Resonance (CMR) with contrast was performed to identify the tissue characteristics further. It showed normal left ventricular systolic function (left ventricular ejection fraction of 54%), with an enlarged myocardial mass and basal and septal hypokinesis   . The riThe patient was treated with intravenous loop diuretics and was ultimately discharged with symptom improvement. 99m-technetium pyrophosphate scintigraphy was performed during the follow-up, negative for cardiac amyloidosis. Also, to obtain material for histologic sampling, an endomyocardial biopsy was performed, showing normal histology findings.1 Moreover, myocardial calcifications generally represent the sequelae of local tissue damage and cellular necrosis and are associated with an increased risk of cardiovascular events (ventricular arrhythmias and systolic/diastolic dysfunction leading to heart failure).2 The patient presented with a history of hypertension, diabetes, and coronary artery disease. Frequently, hypertension is not enough to fully explain myocardial calcification, and it is commonly associated with chronic kidney disease (CKD), where calcification is associated with a phospho-calcic disorder.3 Furthermore, diabetes produces a systemic inflammatory disorder which may contribute to an increased coronary calcification.4 In addition, coronary artery disease is a very common cause of dystrophic myocardial calcification.1 Hypertensive or infiltrative cardiomyopathy cannot be fully excluded despite the CT and CMR findings.Myocardial calcifications deposits may be present in multiple pathophysiological scenarios, such as dystrophic calcifications due to underlying cardiac disease and idiopathic or metastatic systemic diseases.6These calcification patterns may be diagnosed with multiple imaging modalities, being the CTA the gold standard modality for identifying and characterizing myocardial calcifications. Indeed, unlike the well-defined calcification pattern in intrinsic myocardial pathologies, calcium infiltration due to systemic diseases generally has a diffuse pattern. Moreover, CMR might provide further tissue characterization by suggesting myocardial calcification in low signal intramyocardial areas and scarred myocardium surrounding calcifications by LGE images.8 Research has shown that this double helix distribution is rarely found in non-invasive imaging modalities, making this case a living representation of the Torrent Guasp pattern.The Torrent Guasp Theory was originally described macroscopically in post mortem patients, in which myocardial fibers were structured as an extended band from the root of the pulmonary artery to the root of the aorta circumscribing the two ventricles in a double helix pattern fiber. This pattern is responsible for the normal and effective function of the heart, explaining the variation of intraventricular volume within each beat.A case of heart failure with preserved ejection fraction with a diffuse and atypical myocardial calcification following the Torrent Guasp distribution is presented. Multiple causes  may contribute to the origin of the calcification, which is ultimately associated with a worse clinical outcome. Diverse imaging modalities are fundamental to achieving a specific diagnosis and eventually a specific treatment.


A diverting stoma is commonly formed to reduce the rate of anastomotic leak following anterior resection with anastomosis, although some studies question this strategy. The aim of this study was to assess the leak rates and overall complication burden after anterior resection with and without a diverting stoma.A 5-year national cohort with prospectively registered data of patients who underwent elective anterior resection for rectal cancer located < 15 cm from the anal verge. Data were retrieved from the Norwegian Registry for Gastrointestinal Surgery and the Norwegian Colorectal Cancer Registry. Primary end point was relaparotomy or relaparoscopy for anastomotic leak within 30 days from index surgery. Secondary endpoints were postoperative complications including reoperation for any cause.Some 1018 patients were included of whom 567 had a diverting stoma and 451 had not. Rate of reoperation for anastomotic leak was 13 out of 567 (2.3%) for patients with diverting stoma and 35 out of 451 (7.8%) (p > 0.001) for patients without. In multivariable analyses not having a diverting stoma  was associated with increased risk for anastomotic leak. However, there were no differences in overall reoperation rates following anterior resection with or without diverting stoma , and overall complication rates were similar. Reoperation was associated with increased mortality irrespective of the main intraoperative finding.Diverting stoma formation after anterior resection is protective against reoperation for anastomotic leak but does not affect overall rates of reoperation or complications within 30 days. Anastomotic leak following anterior resection for rectal cancer is a major complication, leading to increased morbidity, prolonged hospital stay, additional interventions and in some cases death , 2. EvenIn order to prevent anastomotic leak, formation of a temporary diverting stoma is common following resections with low anastomoses, and two recent meta-analyses have shown lower leak rates in patients receiving diverting stomas , 12. NorThe aim of this study was to assess the anastomotic leak rates and overall complication rates after anterior resection with and without a diverting stoma in a national cohort from the Norwegian Registry for Gastrointestinal Surgery (NoRGast)  linked wst 2014 to December 31st 2018 were identified via NoRGast based on procedure codes according to NCSP  [Patients who underwent elective major resection for rectal cancer from January 1cedures)  for rectcedures) . Tumors cedures) . Data frcedures)  for infoThe national coverage rate in NoRGast has increased during the study period from 20% in 2014 to 75% in 2018 . The lowAccording to NoRGast, anastomotic leak was defined as a leak that required relaparotomy or relaparoscopy (grade C leak)  within 312 cm from anal verge). Age was categorized into three groups . ASA-scores were grouped into low ASA-scores (scores 1–2), and high ASA-scores (scores 3–4). WHO ECOG-scores were dichotomized into low ECOG-score (0–1) and high ECOG-score (2–4). Severe pulmonary disease was defined as having FEV1 < 50 per cent or a vital capacity < 60 per cent of predicted values. Severe cardiac disease was defined as NYHA classification 3–4 or severe arrhythmia requiring mechanical support. Complications were registered according to the Accordion grading system [There was no variable available in the register of whether a total mesorectal excision (TME) or a partial mesorectal excision (PME) had been performed. This is however closely related to tumor level. Hence tumor level was used as a proxy for TME and PME, respectively. Tumor level was measured preoperatively with a rigid proctoscope, and categorized into TME  and PME  or interquartile range (IQR) was calculated when appropriate. Univariable binary logistic regression was used to calculate unadjusted odds ratios (OR). To address and minimize the effects of possible bias resulting from differences in baseline characteristics between patient groups, a stepwise backwards multivariable logistic regression model with adjusted odds ratios (aOR) was used to further analyze the relations between different predictors and outcomes. Variables significant in univariable analyses at a level of p < 0.2 were included in multivariable analysis, and final significance level after multivariable analysis was set to p < 0.05. Relevant variables were tested for significant two-way interactions, and if interactions were found, they were further accounted for in the analyses. Little’s test  of whethThe study was approved by The Regional Committee for Medical and Health Research Ethics  and by the Data Protection Officer at the University Hospital of North Norway.A total of 2302 patients were recorded in NoRGast with an NCSP procedural code for rectal resection during the study time frame. After excluding non-adenocarcinomas, TaTME, endoscopic and emergency procedures, a total of 1796 patients were identified, of whom 1018 patients underwent anterior resection with primary anastomosis. Some 742 of these 1018 operations were laparoscopic procedures including 191 robotic assisted procedures, and 276 were open access procedures  with stratified rates for patients with and without a diverting stoma of 13 out of 567 (2.3%) and 35 out of 451 (7.8%) (p < 0.001), respectively. Leak rate was significantly lower with diverting stomas regardless of tumor level, and tumor level was not a significant predictor for anastomotic leak in univariable regression analyses. In multivariable regression analyses, absence of diverting stoma was associated with an increased risk of reoperation for anastomotic leak with an aOR of 3.77  compared to anterior resection with a diverting stoma . There was no difference in reoperation rates between the groups with and without diverting stomas Table . In NoRGThe overall major complication rates, 30-day and 90-day mortality rates and rates of single-organ and multi-organ failure did not differ between the two groups Table . Median There were no major differences in mortality or morbidity between patients reoperated for anastomotic leaks and patients reoperated for other reasons Table , but LOSIn the present study, reoperation for anastomotic leak within 30 days after anterior resection was significantly less frequent in patients with a diverting stoma. However, stoma diversion did not affect the overall reoperation rate, mortality or morbidity. This has to the authors knowledge not been shown in previous studies. Reoperation was associated with increased mortality irrespective of intraoperative finding, and the total burden of morbidity and mortality within 30 days were similar for patients with and without a diverting stoma.The current evidence of the benefits of diverting stomas following anterior resection is unclear, and studies report diverging results. A recent meta-analysis showed lower anastomotic leak rates and reoperation rates with diverting stomas compared to no stomas , but theAlthough diverting stomas apparently have a protective effect against early diagnosed leaks, several studies highlight the less favorable consequences of stoma formation –18. A teIn the present cohort diverting stomas did not lower morbidity, mortality or reoperation rates within the first 30 postoperative days. Reoperation for bleeding, deep infection and wound dehiscence was performed to the same extent regardless of whether the patient had received a diverting stoma or not. The patients who received a diverting stoma were also reoperated more frequently due to bowel obstruction, and 30% of the reoperations were directly stoma-related. In support of this notion, formation of diverting stomas has been shown to increase short-term complications including stoma related reoperations after anterior resection . FurtherThe results of the present study emphasize the question whether patients undergoing anterior resection derive any benefit from formation of a diverting stoma and if so, how to select these patients. As low tumor level did not represent a significant risk factor for anastomotic leak, the recommendation of diverting stoma formation for anastomosis level < 7 cm from anal verge can be challenged. To explore this issue further a long-term study on outcomes after anterior resection with and without diverting stomas is warranted, assessing both early and late diagnosed anastomotic leaks, long-term overall complication rates, permanent stoma rates and total length of hospital stay. A Norwegian multicenter trial, the Norwegian Stoma Trial, exploring some of these issues is planned for commencement in 2022 . FurtherThis study has some limitations. NoRGast is a newly established register with low coverage rates during the first years of inclusion. As already described, causality between stoma related problems and indication for reoperation cannot be established due to the nature of the study. The present study is an observational registry study and it is possible that there are variables not registered that could have a confounding effect, and that there are factors not registered and hence accounted for that could lead to selection bias. Nevertheless, our findings add to the question whether the benefits of a diverting stoma following anterior resection is outweighed by the overall complication rate.