First recognized in 1990, takotsubo syndrome (TTS) constitutes an acute cardiac condition that mimics acute myocardial infarction commonly in the absence of obstructive coronary artery disease; it is characterized by temporary left ventricular dysfunction, regularly in a circumferential apical, midventricular, or basal distribution. Considering its acute clinical presentation, coronary angiography with left ventriculography constitutes the gold standard diagnostic tool to exclude or confirm TTS. Frequently, TTS is related to severe emotional or physical stress and a subsequent increased adrenergic stimulation affecting cardiac function. Beyond clinical presentation, epidemiology, and novel diagnostic biomarkers, this review draws attention to potential pathophysiological mechanisms for the observed reversible myocardial dysfunction such as sympathetic overdrive-mediated multi-vessel epicardial spasms, microvascular dysfunction, the direct toxicity of catecholamines, lipotoxicity, and inflammation. Considering the long-term prognosis, further experimental and clinical research is indispensable to elucidate further pathophysiological mechanisms underlying TTS before randomized control trials with evidence-based therapeutic management can be performed. First recognized by Sato et al. in 1990 . The RWMNumerous trigger factors have been found to lead up to the onset of TTS in about 70% of TTS patients . EmotionThe most frequent symptoms of TTS are chest pain (76%), dyspnea 47%), and syncope (8%) 7%, and s.The clinical presentation of TTS triggered by severe physical stress may be superimposed by the symptoms of the underlying acute disease. Indeed, patients with ischemic stroke or seizure-caused TTS have been shown to have less common chest pain ,24 whichWith respect to the prognosis, TTS was originally thought to be a nonthreatening disease . HoweverNotably, a multicenter study over 1000 patients from the German and Italian Stress Cardiomyopathy (GEIST) registry yielded four variables as independent predictors of in-hospital complications: a history of neurologic disorders, RV involvement, LVEF, and male sex . TherefoIn summary, a distinction between AMI and TTS based on clinical presentation is not feasible. The prognosis of TTS ranges from a rapid recovery to poor early and long-term outcomes. Thus, risk stratification considering physical stressors, comorbidities , a high Killip class upon admission, right ventricular involvement, and LVEF is essential in order to identify patients at risk.Approximately 1–2% of all patients and up to 10% of women attending clinics with acute coronary syndrome (ACS) have been diagnosed with TTS ,36,37. WAround 90% of TTS patients are women, with a mean age of 68.5 years, and about 80% are older than 50 years ,41. IndeEven though there has been a lack of large-scale studies concerning the impact of ethnicity in TTS presentation and outcomes, a study with a total of 206 TTS patients displayed ethnical disparities; African-Americans who suffered TTS presented less frequently with chest pain or depression and anxiety as comorbidities . MoreoveThe reported recurrence rate of TTS ranges from 0% to 22%, depending on the duration of follow-up . A systeDifferentiation between TTS and AMI is often challenging due to their similarity in clinical presentation, electrocardiography (ECG) abnormalities, and cardiac biomarkers . TherefoCommon ECG findings in TTS are ST-segment elevation 44%) and T inversion (41%), mostly in the precordial leads ,53. When4% and T Dynamic changes in the ECGs of TTS patients have prognostic value. It is crucial to perform serial ECGs from admission to 72 h after. Indeed, 60% of patients develop QT interval prolongation after 72 h. Dynamic increases of QTc intervals after hospitalization are associated with better prognoses. On the other hand, prolonged QTc intervals at admission could be rated to a higher risk of cardiovascular rehospitalization at follow-up . MoreoveCompared with patients with STEMI, patients with TTS typically present lower levels of creatine kinase-MB (CKMB) and lower peak levels of cardiac troponin due to a relatively mild or lack of tissue necrosis ,60. HoweBeyond these established biomarkers, several novel markers have been proposed for differentiating TTS from AMI . For insThe soluble suppression of tumorigenicity 2 (sST2), part of the interleukin (IL)-1 receptor family, was shown to predict TTS in patients admitted to the intensive care unit (ICU) , and, inAt admission, the plasmatic levels of IL-6 are lower in TTS patients compared to AMI, patients while IL-7 levels are elevated . SantoroWith respect to further stress responsive cytokines, the ability of growth differentiation factor-15 (GDF-15) to distinguish TTS from STEMI was shown by Stiermaier et al. . In partFurthermore, Jaguszewski et al. postulated a signature of four circulating microRNAs as a strong biomarker to differentiate TTS from STEMI; the signature comprises miR-26a, miR-1, miR-133a, and miR-16, and it was found to be able to distinguish TTS from healthy and STEMI patients, with a specificity of 79% and a sensitivity of 74% for TTS vs. healthy subjects, as well as a specificity of 70% and a sensitivity of 97% for TTS vs. STEMI patients . InteresIn addition, a more recent microarray analysis identified A2M, ALB, APOB, APOE, C3, MFGE8, and SAA1 as hub genes of TTS that might be future diagnostic biomarkers or molecular targets for the treatment of TTS . HoweverTaken together, numerous biomarkers have been proposed for the differential diagnosis of TTS, but none of these could render invasive coronary angiography redundant. Nevertheless, a recent microarray and circulating microRNA analysis have revealed promising targets for further research to support physicians in the diagnosis of TTS.Even though echocardiography constitutes the first-line imaging tool in patients with suspected TTS, CAG is of decisive diagnostic importance to rule out alternative diagnoses . As justEchocardiography constitutes the first-line imaging modality to assess alterations in ventricular function such as RWMAs, RV involvement, hemodynamic status, mechanical complications (LVOTO), pericardial effusion, LV thrombi, and pulmonary artery systolic pressure . In contRWMA and LVEF commonly recover within a few weeks, while the impairment of global longitudinal strain, untwist rate, and time to peak untwisting have been reported to persist for weeks to months after acute TTS ,97, possFinally, contrast echocardiography may be used to improve RWMA and ventricular thrombus detection , while 3CMR constitutes the gold standard for the qualitative and quantitative assessment of RWMAs and the accurate quantification of LV and RV volumes and function, thus allowing for a comprehensive evaluation of structural and functional abnormalities in patients with TTS . FurtherMyocardial tissue characterization constitutes a major advantage of CMR due to its ability to discriminate reversible from irreversible myocardial injury; the absence of late gadolinium-enhancement (LGE) in dysfunctional LV regions—which is defined as a diagnostic criterion for TTS —indeed aCMR should be used in the acute phase of TTS, when echocardiographic images are suboptimal, or when differential diagnosis such as myocarditis requires a different therapeutic strategy . In the 123I-MIBG) scintigraphy have shown a functional alteration in presynaptic sympathetic neurotransmission in patients with TTS [Though the exact underlying pathophysiological mechanisms of TTS are still elusive, the pivotal importance of sympathetic hyperactivity is generally accepted  Figure . Increaswith TTS . These awith TTS ,116. Furwith TTS ,118. In with TTS .Overall, increased sympathetic stimulation is crucial to TTS. However, the exact mechanism by which a catecholamine surge orchestrates myocardial stunning in the diversity of regional ballooning remains elusive; thus, several pathophysiological theories are discussed below.Epicardial spasm due to sympathetic hyperactivity has been proposed as a possible underlying mechanism in TTS . Indeed,Furthermore, TTS has been associated with Raynaud syndrome and migraines, supporting the pathophysiological relevance of vasomotor dysfunction . In accoAdditionally, myocardial bridging was proposed as a potential factor in the pathogenesis of TTS . HoweverPlaque rupture, thrombosis, and subsequent transient ischemia followed by rapid lysis have been discussed as a mechanism for myocardial stunning in TTS. Indeed, a high prevalence of atherosclerotic plaques and highly vulnerable thin cap fibroatheromas were reported in TTS patients by using optical coherence tomography. However, ruptured plaques or intracoronary thrombi were not detected, speaking against a causal association between plaque rupture and TTS ,129. BesAs delineated before, most patients presenting with TTS have angiographically normal coronary arteries or non-obstructive CAD. Thus, coronary microcirculation has been proposed as a possible actor that may play a decisive role in the pathogenesis of TTS. Indeed, coronary microcirculation, involving the coronary pre-arterioles and arterioles (< 500 μm diameter), regulates coronary blood flow in response to mechanical, metabolic, and neural factors, thus explaining its dysfunction curtail myocardial perfusion . For ins2+-adenosine-triphosphatase (SERCA2a) gene expression and myocardial contractility dysfunction due to a decreased Ca2+-affinity of SERCA2a [1-adrenergic receptor signaling has been identified to downregulate SERCA2a gene expression via the cyclic adenosine monophosphate responsive element binding protein-1 and nuclear factor of activated T-cells pathways [Typical structural changes due to catecholamine overload include contraction band necrosis, an increase of the extracellular matrix, and mild neutrophil infiltration . On a mo SERCA2a . Accordipathways ,147.sα to Giα protein pathway, which is called stimulus trafficking—all of which results in a negative inotropic effect at the LV apex [i protein switch, constituting a physiological balance to prevent excessive catecholamine-mediated damage [Grippingly, in mammals, LV β-adrenergic receptor (β-AR) density is highest and sympathetic innervation is the lowest in the apex ,149, ind LV apex . Therefod damage . Hence, d damage . While td damage ,152, Nakd damage . Consided damage .Supporting the relevance of the desensitization and downregulation of G protein-coupled receptor signaling in TTS, a L41Q polymorphism of GRK5, one of the two isoforms predominant in the heart, has been shown to render patients susceptible to TTS . HoweverRegarding the aforementioned high prevalence of TTS in postmenopausal females, one could suggest a hormonal influence. Indeed, a reduction of estrogen levels following menopause has been revealed to enhance the vulnerability to TTS in women . Estroge++CD16– macrophages, as well as a decrease in intermediate CD14++CD16+ and nonclassical CD14+CD16++ monocytes. While USPIO enhancement was no longer detectable after five months, increased IL-6 levels and a decreased number of intermediate monocytes persisted, pointing to a chronic low-grade inflammation [Inflammation in TTS has received growing interest in the recent years; however, the first indication of its relevance was published in a case report by Sato in 2005 that considered a 70-year-old woman suffering TTS associated with microscopic polyangiitis. In this case, anti-inflammatory therapy using (methyl)prednisolone completely resolved ventricular dysfunction . Indeed,ammation . Accordiammation . Moreoveammation .To further determine the inflammatory characteristics of TTS, Wilson et al. used a well-established experimental model of stress-induced TTS initiated by isoprenaline injections in female Sprague Dawley rats, showing early neutrophil infiltration followed by macrophages after isoprenaline injection . ImportaDrawing further attention to the innate immune system, the expression of apoptosis morphological patterns and Toll-like receptors (TLR) were found to differ in the course of TTS-induced rodents in comparison with the controls . Fitzgib31P-magnetic resonance spectroscopy has been used to determine the phosphocreatine/γ-adenosine triphosphate (PCr/γATP) ratio, which constitutes a well-established tool for the in-vivo measurement of myocardial energetic status [2-adrenoceptor stimulation is assumed to increase NO release [In TTS patients, c status , and datc status . Indeed,c status . While pc status . Moreovec status . Indeed, release ,178. The release  or the d release  due to g release . Fascina release . Moreove release .β-methyl-p-iodophenyl penta-decanoic acid (123I-BMIPP) and serial tallium-201 (201Tl) dual-isotope myocardial single-photon emission computed tomography (SPECT), Kurisu et al. indeed demonstrated that perfusion defects had a reduced extent when measured by 201Tl compared with 123I-BMIPP , thus suggesting a more severe impairment of myocardial fatty acid metabolism than myocardial perfusion [v1.2, leading to a reduced calcium time to transient under catecholamine-induced stress, mimicking some pathophysiological mechanisms that have been observed in acute TTS and enabling the further in vitro exploration of underlying mechanisms. In addition, TTS-iPSC-cardiomyocytes (CMs) displayed a diminished contraction force and a higher susceptibility to catecholamine-stimulated inotropy compared with controls. Intriguingly, catecholamine-treated TTS-iPSC-CMs displayed increased lipid accumulation, which was confirmed by differentially expressed the lipid transporters carnitine palmitoyltransferase-1c and fatty acid translocase [Shao et al. revealed intramyocardial lipid droplet accumulation in rodent cardiomyocytes in response to catecholamine surge . This haerfusion  and possnslocase , furtherIn summary, inflammation can be considered to be a fundamental part of the pathophysiology of TTS. However, the cause–effect relationship remains unknown. Hence, future experimental studies should focus these causative mechanisms of the disease. However, from a translational perspective, anti-inflammatory therapies constitute a promising therapeutic approach in TTS; thus, intervention studies should be considered.TTS constitutes a complex acute cardiac condition mimicking AMI that usually occurs in the absence of obstructive-CAD, leading to RWMA with characteristic circumferential patterns and an impairment of LV contractility. Due to its acute clinical presentation, coronary angiography with left ventriculography is considered to be gold standard diagnostic modality to confirm or exclude TTS. However, CMR is of importance for the differential diagnosis in patients with suspected TTS when echocardiographic images are suboptimal or when the diagnosis of another type of MINOCA  requires a different therapeutic approach. With respect to the prognosis, the long-term mortality of TTS exceeds that of patients with STEMI. TTS is frequently associated with severe emotional or physical stress and a subsequent increased adrenergic stimulation that affects cardiac (micro)perfusion and function. Several pathophysiological mechanisms that do not reciprocally exclude each other, such as sympathetic overdrive-mediated multi-vessel epicardial spasms, microvascular dysfunction, the direct toxicity of catecholamines, and inflammation, have been proposed. The predominance of postmenopausal female among TTS patients indicates estrogen deficiency as an important predisposing factor. However, further experimental and clinical research is required to illuminate the pathophysiological mechanisms underlying TTS before randomized control trials with evidence-based therapeutic management can be done.


Doxorubicin remains one of the most common causes of cardiotoxicity in patients with lymphoma, leading to significant morbidity and mortality. Early decline in left ventricular (LV) ejection fraction predicts chemotherapy-induced cardiotoxicity and mortality, but limited data exist on doxorubicin-induced subclinical right ventricular (RV) dysfunction. We investigated dose-dependent subclinical doxorubicin-induced RV dysfunction in lymphoma patients.Thirty-five patients with adult lymphoma treated with doxorubicin were studied. All patients had normal baseline LV ejection fraction (LVEF > 55%), and no known cardiopulmonary disease. We studied the dose-dependent effect of doxorubicin on RV strain by 2D speckle-tracking echocardiography (STE) using a vendor-independent software (TomTec). Images were analyzed offline by two independent observers blinded to the clinical characteristics of the study population. Baseline LVEF, RV fractional area change (RV FAC), RV free wall strain (RV FWS), and RV global longitudinal strain (RV GLS) were measured prior to chemotherapy initiation and compared with echo studies obtained at a 6-month follow-up interval. Patients served as their own controls. Comparisons between pre- and post-therapy were achieved using paired Student’s t-tests or Chi-Square test.− 2. There was there was significant decline in RV FAC (47.3 ± 4.4% vs. 43.7 ± 3.9%), RV FWS (− 24.9 ± 3.3 vs. -22.2 ± 2.9), and RV GLS (− 22.4 ± 4.1 vs. -20.6 ± 3.4) ; but no significant decline in LVEF during the 6-month follow up . At cumulative doxorubicin dose ≥200 mg m− 2 we found a significant decline in RV FAC , RV FWS , and RV GLS .The Interobserver Intraclass Correlation Coefficient for RV GLS, RV FAC and RV FWS, was 0.87, 0.81 and 0.79, respectively. The mean age was 51 ± 13 years, 40% women, 60% white. The mean cumulative doxorubicin dose was 239 ± 104 mg m− 2. Additional studies evaluating the long-term prognostic implications of RV dysfunction in this population are essential.In this cohort of adult lymphoma patients, doxorubicin-based therapy was associated with subclinical RV dysfunction, but not LV dysfunction, at a cumulative dose ≥200 mg m Anthracyclines are commonly used anti-neoplastic agents in the treatment of a variety of malignancies, including lymphoma; and cardiotoxicity remains an irreversible complication of anthracycline-based chemotherapy. Most current guidelines and clinical trials describe cardiotoxicity as changes in resting cardiac systolic function  defined In patients receiving doxorubicin, left ventricular myocardial strain assessed by speckle tracking echocardiography (STE) and cardiovascular biomarkers such as natriuretic peptides and high-sensitive cardiac troponins can detect subclinical cardiotoxicity and predict future risk of heart failure . FurtherWhile the clinical implications of doxorubicin on sub/clinical LV dysfunction have been well established, data are sparse regarding its effects on right ventricular (RV) function. RV function has independent prognostic implications in patients with or without LV systolic dysfunction, and may predict subclinical LV dysfunction in animal models receiving anthracyclines .In this study, we explore overall as well as dose-dependent associations between doxorubicin and subclinical RV function parameters in lymphoma patients using 2D STE.We included adult patients with a clinical diagnosis of lymphoma who received doxorubicin-based chemotherapy in an urban academic center. The patients were regarded as eligible for this study if they had not received prior anthracycline or radiation therapy to the mediastinum. Patients with previous cardiac diseases including congestive heart failure (CHF), were excluded. The study was reviewed and approved by the Institutional Review Board at Rush University Medical Center.All patients had normal baseline biplane LVEF > 55%, and each patient served as their own control. Baseline LVEF, RV fractional area change (RV FAC), RV free wall strain (RV FWS), and RV global longitudinal strain (RV GLS) were measured prior to chemotherapy initiation and compared with the echo studies post treatment. The average follow-up period from pre- to post-doxorubicin echocardiography was 6 months.A standard chemotherapeutic regimen of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) was administered to each of the patients. All patient receiving R-CHOP received 6 cycles and each cycle was made up of: cyclophosphamide 750 mg/m2; vincristine 1.4 mg/m2; doxorubicin 50 mg/m2 on day 1; prednisone 100 mg on days 1 to 5; and rituximab 375 mg/m2 every 21 days).Comprehensive echocardiographic examinations were carried out and analyzed using General Electric, Vivid 7 Dimension imaging system device  with a 3.5 MHz transducer in accordance with the standard recommendations of the American Society of Echocardiography guidelines  × 100 [− 2 versus > 200 mg m− 2. Cutoff was chosen at 200 mg m− 2, as it is the lowest cumulative doxorubicin dose defined with significant LV systolic dysfunction, and thus, cardiotoxicity in the latest guideline consensus [P-value < 0.05 was considered statistically significant.All calculations were performed using SPSS/PC statistical program . Continuous variables were reported as means ± standard deviation while categorical variables were expressed as numbers, percentages or ratios. The differences for continuous variables over time were analyzed using general linear model for repeated measures. Multiple regression analysis was performed to observe between cumulative anthracycline doses, and RV FAC, GLS, and FWS. Paired two tailed t-tests were applied for post-hoc analyses. Multivariate regression analysis was performed to adjust for covariates including age, body mass index (BMI), pulmonary hypertension, chronic obstructive pulmonary disease, dyslipidemia, diabetes, hypertension, and heart rate at time of echocardiography. We also studied the dose-dependent effect of doxorubicin on RV function by dividing the patients into 2 groups of low cumulative doxorubicin vs. higher cumulative doxorubicin doses, defined as < 200 mg m− 2 and mean follow up period was 6 months. For the measurement of RV GLS, RV FAC and RV FWS, the interobserver ICC was 0.87, 0.81 and 0.79 respectively, suggesting satisfactory reproducibility.A total of 35 patients with a mean age of 51 ± 13 years, were included in the final analysis; 40% were women; 60% white, 14% African American, 8% Asian, and 8% Hispanic (Table p = 0.37). We also observed a dose-dependent decline in RV function at higher (≥ 200 mg m− 2) vs. lower (< 200 mg m− 2) doses of doxorubicin from pre- to post-doxorubicin therapy; RV GLS p = 0.03, RV FAC and FWS p < 0.01  and RV FAC (P = 0.045) on multi regression analysis (Table Furthermore, cumulative dose of doxorubicin was significantly associated with percent decline in RV FWS (C P = 0.05 on multC P = 0.05 on multC P = 0.05 on multDoxorubicin-induced LV cardiotoxicity has been well-studied and established. Our study showed that in a dose-dependent manner, doxorubicin was associated with subclinical RV dysfunction measured by 2D STE, but not changes in LVEF, in lymphoma patients with no known baseline heart disease. To our knowledge, our study is one of the first of its kind to show that subclinical RV dysfunction parameters were associated with higher cumulative doses of doxorubicin even though LVEF was not. Zhao et al. recently demonstrated subclinical changes in RV function parameters after 6 cycles of anthracycline chemotherapy . FurtherEarly detection of cardiotoxicity and prevention of cardiovascular events is especially challenging in cancer patients receiving cardiotoxic chemotherapy. Several studies have demonstrated the importance of limiting anthracycline dose to minimize cardiotoxicity and cardiac mortality . Since eThe conventional criteria for diagnosis of chemotherapy-related cardiac dysfunction relies on changes in LVEF, which has high measurement variability and is not a prognostic indicator . However. Though less established than FAC, the advantage of RV GLS and FWS measurement is that the measurements are both angle-independent and less sensitive to loading conditions [The RV plays an increasingly important role in cardiac-related morbidity and mortality in patients with cardiopulmonary disease, and RV dysfunction is associated with worse outcomes . Howevernditions . Due to nditions , 20.In our study, decline in RV FWS and FAC but not RV GLS was strongly associated with cumulative doxorubicin dose. Although non-significant, there a trend in correlation showing more abnormal RV GLS with higher doxorubicin dose Fig. . In comp− 2, then at 450 mg m− 2 [Cumulative anthracycline exposure has been studied and is largely associated with the risk of cardiac toxicity , 22. We  mg m− 2 . Our stu mg m− 2 .Our study was limited by its small sample size with limited power, which implies that our findings, including strain and dose-dependent trend towards increased all-cause mortality, could be even more robust with a larger sample of patients. The retrospective nature of the study likely adds some bias to our study findings and limits clinical correlations due to non-standardized clinical assessments that lack longitudinal correlation to the strain parameters assessed. We also could not assess associations between RV strain parameters and prognostic biomarkers such as high-sensitive troponin or natriuretic peptides. As this is primarily an imaging study, subclinical cardiac status was the focus of correlation.In this cohort of adult lymphoma patients without known heart disease, despite absence of change in LVEF, we demonstrated the dose-dependent effect of doxorubicin therapy on RV subclinical dysfunction by 2D STE. 2D STE is a sensitive and reliable non-invasive method that can detect subclinical LV dysfunction in cancer patients receiving cardiotoxic chemotherapy, before a reduction in LVEF. RV dysfunction is an independent prognostic marker and a predictor of mortality in patients with cardiomyopathy and heart failure. Based on our study findings, we propose that in addition to LV, RV function monitoring may be a cost-effective tool for early detection of subclinical cardiac dysfunction during chemotherapy. Additional studies evaluating the long-term prognostic implications of RV dysfunction in this population are essential. In the future, larger prospective studies that focus on the evaluation of RV strain parameters in correlation with both biomarkers and LV strain are paramount to the validation of this study in the setting of doxorubicin chemotherapy.0.


In this meta-analysis we aimed to determine the weighted mean of T2 and T2* mapping values in patients with myocardial infarction (MI), heart transplantation, non-ischemic cardiomyopathies (NICM) and hypertension, and the standardized mean difference (SMD) of each population with healthy controls. Additionally, the variation of mapping outcomes between studies was investigated.The clinical application of cardiovascular magnetic resonance (CMR) T2 or T2* values measured in patients were included. The SMD was calculated using a random effects model and a meta-regression analysis was performed for populations with sufficient published data.The PRISMA guidelines were followed after literature searches on PubMed and Embase. Studies reporting CMR T2 values were higher in patients with MI, heart transplantation, sarcoidosis, systemic lupus erythematosus, amyloidosis, hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and myocarditis  compared with controls. T2 values in iron overload patients  and Anderson-Fabry disease patients  did both not differ from controls. T2* values were lower in patients with MI and iron overload  compared with controls. T2* values in HCM patients , DCM patients  and hypertension patients  did not differ from controls. Multiple CMR acquisition and patient demographic factors were assessed as significant covariates, thereby influencing the mapping outcomes and causing variation between studies.One hundred fifty-four studies, including 13,804 patient and 4392 control measurements, were included. T2 and T2* mapping to distinguish affected myocardium in patients with cardiomyopathies or heart transplantation from healthy myocardium seemed to be confirmed based on this meta-analysis. Nevertheless, variation of mapping values between studies complicates comparison with external values and therefore require local healthy reference values to clinically interpret quantitative values. Furthermore, disease differentiation seems limited, since changes in T2 and T2* values of most cardiomyopathies are similar.The clinical utility of T Ventricular dysfunction in ischemic cardiomyopathies is triggered by impaired coronary blood supply to the myocardium . In non-1, T2 and T2* mapping as part of the CMR exam [1 and T2 mapping in their latest position statement [1 mapping has already been acknowledged and included in some guidelines [2 and T2* mapping instead of T2-weighted imaging [Early diagnosis of cardiomyopathy is important to initiate appropriate treatment , 8. PhysCMR exam . In linetatement . The cliidelines , 21, 22. imaging , 22–24.2 mapping values vary due to different water concentrations in the myocardium and therefore T2 mapping could be useful in infiltrative cardiomyopathies, such as iron overload and Anderson-Fabry disease, and in myocardial injury diseases featuring edema, necrosis, and hemorrhage formation [2 could contribute in the diagnosis of heart transplant rejections as edema correlates with acute heart transplant rejection [2, T2* mapping values mainly depend on magnetic field inhomogeneities and are therefore clinically useful in iron related diseases, and also enable assessment of hemorrhage formation [The Society for Cardiovascular Magnetic Resonance (SCMR) released clinical recommendations about parametric imaging in CMR . T2 mappormation , 25, 26.ejection , 27. In ormation , 28, 29.2 and T2* mapping in healthy subjects have been investigated in multiple studies [2 and T2* mapping values in the HF-related cardiomyopathies and heart transplantations, and standardized mean differences (SMD) with healthy controls. Knowledge of these ranges can help determine the clinically applicability of quantitative techniques. Furthermore, we aim to investigate the presumed heterogeneity of studies leading to variation in mapping outcomes, to emphasize the importance of mapping standardization.Reference values of T studies –33. The  studies , 33. The2 or T2* mapping in humans. The search contained terms related to T2 or T2* mapping and cardiac diseases  statement  and the 2 and/or T2* mapping values acquired at 1.5 T or 3 T. Studies were excluded if the article was not available in English or in full text.In this meta-analysis we accepted published results from randomized control trials, cohort studies and observational studies in peer-reviewed journals if they included adults aged 18 years and older with NICM or ischemic cardiomyopathy, heart transplant patients or adults with increased cardiovascular risk, and reported CMR derived TTitles and abstracts proposed by the databases were assessed for eligibility by one author and checked by a second author . After consensus between these investigators, the full-text reports of these eligible studies were independently assessed by two investigators for final inclusion. The study quality was systematically evaluated with the Newcastle-Ottawa quality assessment scale (NOS) . This sc2 and T2* values, as well as CMR imaging acquisition related information, such as; field strength, vendor, sequence and sequence parameters were extracted. Data were reported as mean ± standard deviation (SD) and data reported as median with interquartile or full range were converted using the methodology of Hozo et al. [Data were extracted from the included studies by one author and checked by a second author . Relevant data regarding patient characteristics, such as; study population, age, gender, body mass index, To et al. . Healthy2 and T2* values per disease and combined into a random effects model to determine the SMD and the 95% confidence interval (CI). The heterogeneity of the included studies was defined with I2 being significant if I2 ≥ 50% (P <  0.05) by using a χ2 test. This heterogeneity was further tested by a meta-regression, sensitivity and bias analysis. Available covariates were tested for their association with the myocardial T2 and T2* values using a backwards elimination model and remaining significant covariates (P <  0.05) were included into a mixed effect model of the data. Publication bias was assessed by inspection of the funnel plots with the Egger regression asymmetry test and a sensitivity analysis was performed by omitting each study sequentially and recalculating the model. A meta-analysis was performed in each population with at least 10 published studies, as stated by the PRISMA guideline [The included data were divided into two groups of reported Tuideline . Review 2 data & number of studies reporting T2* data): A total of 31 (22 T2 & 13 T2*) studies were included in the myocardial infarction (MI) population [2 & 0 T2*) in heart transplantation [2 & 70 T2*) in iron overload [2 & 0 T2*) in sarcoidosis [2 & 0 T2*) in systemic lupus erythematosus (SLE) [2 & 0 T2*) in amyloidosis [2 & 0 T2*) in Anderson-Fabry disease [2 & 2 T2*) in HCM [2 & 2 T2*) in DCM [2 & 0 T2*) in myocarditis [2 & 1 T2*) in hypertension [2 and T2* values are dependent on field strength [2 and T2* mapping obtained in control subjects were recorded as values from healthy subjects, unless the control population was explicitly defined otherwise in the “population” column of Table The search in PubMed and Embase revealed respectively 555 and 545 articles, and one article was manually added . After rpulation , 39–68, antation , 69–78, overload –148, 2  –154, 2  in HCM –162, 9  in DCM , 163–170carditis , 171–187rtension   patients was 28.5 ± 6.8 ms and 34.7 ± 3.7 ms in controls [2* values in MI patients  in the myocardium , while the mixed effects model did not show funnel asymmetry (P = 0.60).The weighted mean Tcontrols –49 , and with a significant heterogeneity. Furthermore, infarct core values were explicitly reported in five studies [2* value at 1.5 T of infarct cores was 16.1 ± 4.2 ms and at 3 T this was 16.1 ± 7.6 ms , while the heterogeneity remained significant. Multiple studies reported the remote myocardium as control which had a weighted mean T2* value at 1.5 T of 34.0 ± 4.9 ms and 30.5 ± 1.0 ms at 3 T , though there are probably other covariates which were not tested due to insufficient data. Publication bias was detected with five possibly missing studies, however no significant asymmetry was found for either the random effects model (P = 0.10) or the mixed effects model (P = 0.55).The weighted mean Tcontrols –63 . The meta-analysis showed older patients, a short period between intervention and CMR, lower LVEF in patients and performing CMR on 1.5 T to increase the difference with controls. The used CMR acquisition sequence was also found as significant covariate, nevertheless none of the specified sequences provided clearly larger differences. There were no other significant residual factors remaining that accounted for the heterogeneity (I2 = 80%). Again, publication bias was found with two missing studies, however no significant asymmetry was found for either the random effects model (P = 0.76) or the mixed effects model (P = 0.58). Core T2 values were reported in five studies [2 value at 1.5 T of infarct cores was 51.9 ± 4.6 ms and at 3 T no values were reported . The weighted mean T2 value at 1.5 T of remote myocardium was 49.2 ± 2.5 ms and at 3 T this was 45.0 ± 3.0 ms . Transplant rejection, lower LVEF and older patients resulted in larger differences between patients and controls.The weighted mean Tcontrols , 69–78  and without cardiac involvement (T2* ≥ 20 ms). Each study that included both iron overload patients and controls showed significantly lower T2* values in patients [2* values [2* values in patients compared to controls [2* sequence was determined as a covariate. These covariates, however, only partly accounted for the heterogeneity in the mixed effects model (I2 = 80%), while other tested regressors  had no significant influence. Based on the high remaining heterogeneity there should be other covariates which were not tested due to insufficient data. Significant funnel asymmetry (P <  0.01) was only found for the random effects model suggesting five missing studies with populations showing higher T2* values compared to healthy subjects.The weighted mean Tcontrols –147  [2* value at 1.5 T in cardiac involved iron overload patients was 11.8 ± 3.7 ms and at 3 T no T2* values were reported  and this difference was also larger than controls compared to the overall iron overload population.The type of iron overload patient was one of the covariates and therefore an additional analysis was performed on T< 20 ms) , 145. Th2 values at 1.5 T in iron overload patients was 56.0 ± 13.6 ms and 58.3 ± 3.2 ms in controls [2 values for iron overload patients at both 1.5 T and 3 T, while Camargo et al. [2 values in iron overload patients at 1.5 T. The random effects models of all studies combined resulted in no significantly lower T2 values for iron overload patients compared to controls  patients was 55.7 ± 4.9 ms and 50.6 ± 3.3 ms in controls [2 values in SLE patients  (50.4 ± 3.8 ms), while patients without LVH showed similar T2 values (47.8 ± 1.7 ms) to controls. Insufficient studies were available for further analysis regarding covariates and publication bias. Furthermore, there were no studies performed with T2 values on 3 T and there were no data that described T2* values.The weighted mean T± 3.0 ms , 158  and resulted in a larger SMD between myocarditis patients and controls when the same percentages of men was used in both groups, a significantly decreased LVEF was seen in patients, six echoes were acquired for the mapping, a Siemens Healthineers CMR vendor was used, a bigger slice thickness was used, and when the patients were scanned in the acute phase of myocarditis. Significant asymmetry was not found for either the random effects model (P = 0.12) or the mixed effects model (P = 0.10).The weighted mean Tcontrols , 171–185controls , 187 . On sarcoidosis, SLE, amyloidosis, sarcoidosis, Anderson-Fabry disease and HCM insufficient studies were reported for further analysis, nevertheless the available data suggested T2 values to be higher within these diseases, with an exception for Anderson-Fabry disease patients without LVH. Furthermore, this meta-analysis confirmed that T2* mapping can differentiate between healthy myocardium and myocardium affected in MI and iron overload, since T2* values were lower in both of these populations [2* mapping studies also gave some indication of lower T2* values compared to controls, however this was overall not significant. For all included cardiac diseases in this meta-analysis the T2 values were higher, with iron overload patients as an exception showing lower T2 values, and T2* values were lower. These similarities in T2 and T2* values between cardiac diseases prevent further differentiation in disease type, as opposed to differentiation from the healthy.Quantitative analysis of factors that modulate myocardial Tulations . Althoug as well , no signulations . For HCM2 and T2* values in healthy subjects showed large variation between studies, which could partly be due to the lack of acquisition standardization. In the standardized CMR imaging guideline and protocol published in 2013 [2* mapping was only described as a clinical applicable technique to assess cardiac iron deposition and T2 mapping was defined as a research-domain technique [2 mapping sequences were stated as optional since there was no standardization yet [2 values. In 2017, clinical recommendations were released regarding parametric imaging of both T2 and T2* mapping and defined standardized data acquisition and analysis [2 and T2* values should be determined in order to clinically use these quantitative techniques, which is now confirmed by this meta-analysis considering the wide variation of healthy T2 and T2* values  and 50.0 ± 2.5 ms at Siemens (n = 22) and T2* values of 34.1 ± 6.5 ms at Philips (n = 5), 30.8 ± 4.5 ms at Siemens (n = 3) and 55.0 ± 13.0 ms at General Eletric (GE) (n = 1), and on 3 T healthy control T2 values of 44.7 ± 5.8 ms at Philips (n = 6) and 48.0 ± 3.0 ms at Siemens (n = 5), and T2* values of 23.9 ± 4.7 at Philips (n = 2), 21.0 ± 4.8 ms at Siemens (n = 1) and 21.0 ± 6.4 ms at GE (n = 1). These differences in vendor and field strength should be kept in mind when T2 and T2* values are used within a clinical protocol.Reported T in 2013 , T2* mapechnique , 195. T2tion yet , which lanalysis . They stes Figs. . The use* values . Furthern onward . This men onward . This an2 and T2* acquisitions [2 and T2* values. The clinical recommendations on acquisition and ROI placement are described specifically per disease [2 values measured in positive LGE myocardium should therefore be interpreted cautiously. Analysis of T2 in diffuse diseases, such as HCM and DCM, were mostly performed based on one or three short axis (SAx) slices using global assessment [2 analysis should also include a single 3 chamber or 4 chamber view acquisition additionally to basal and mid-ventricular SAx slices [2 values were only acquired from a LGE hyperintense based ROI [2 signal intensity [2* values [2 and T2* outcome and the separate analysis showed the infarct zone to have a larger T2 difference with controls than the infarct core, while the infarct core showed a larger T2* difference with controls than the infarct zone. Lastly, for studies including iron overload patients most T2* measurements were performed in the intraventricular septum for reproducibility, because the lateral wall often contains dephasing artefacts. Nevertheless, some studies reported an average of the mid-ventricular SAx slice [2* values due to aforementioned artefacts.In addition to the clinical guideline on Tisitions , followi disease , and thi disease . T2 valusessment , 164–169sessment . In patcx slices . Only onx slices , while fx slices –157. In x slices . Most inx slices , 63, 65,x slices  or threex slices  SAx slicx slices , 185, hoased ROI , 187. Alased ROI , 68, 2SDntensity , 59, 60 * values , 43, 56.Ax slice , 134 or Ax slice , 127–1322 and T2* mapping outcomes. These covariates included the use of remote myocardium as control values instead of healthy controls, the timing of CMR acquisition after reperfusion, and the sequence that was used. The first covariate that included the use of remote myocardium as control, showed that remote myocardium is physiologically different from healthy tissue and therefore is not an appropriate control tissue [2 values in humans at the same day and at 10 days post-PCI, compared to 3 days post-PCI [2 values at 3 days post-PCI compared to the same day or at 7 days post-PCI. The third covariate showed that the use of a spin-echo based sequence provides larger differences between MI patients and controls, than the gradient-echo-spin-echo or T2-prepared balanced steady-state free procession sequences, while the latter two are currently recommended in the general guideline [2 and T2* mapping outcomes in addition to the ones identified here.In this meta-analysis including MI patients other covariates aside from the ROI placement had a significant effect on Tl tissue , 198. Fol tissue  . These post-PCI . These rpost-PCI  that repuideline . Lastly 2 values [2 values than controls [2 values in heart transplant patients may also be related to the inflammatory changes from the transplantation process. The exploratory meta-analysis, however, indicated that positive rejection was a significant covariate to result in larger differences of T2 values between heart transplant patients and healthy controls [2 mapping for early detection of heart transplant rejection.In this meta-analysis including heart transplant patients the main distinct covariate was the rejection status of the transplanted heart. Acute cellular rejection is characterized by infiltration of inflammatory cells accompanied with edema resulting in higher T2 values , 200, wh2 values , 76, 200controls , 71, 75,controls , 73, 77,2* value for iron overload patients was 27.2 ± 13.7 ms, which was above the established iron overload cut-off (T2* < 20 ms) [2* values without distinguishing between cardiac or non-cardiac iron overload involvement. Some studies provided T2* values of cardiac involved patients using < 20 ms as a clinical cut-off [2* value of these cardiac involved patients was only 11.8 ± 3.7 ms, which was significantly lower than the controls. The type of controls should ideally only include healthy volunteers, however in some studies also non-cardiac involved iron overload patients were used as controls. The T2* value from real healthy volunteers of 32.4 ± 5.6 ms [2* < 20 ms cut-off to establish cardiac involvement could be challenged. The current recommendation advises to perform T2* mapping on 1.5 T, since higher field strengths show more susceptibility artefacts [In this meta-analysis all transfusion-dependent diseases leading to iron overload were evaluated in one group including thalassemia, sickle cell disease and anaemias . The ove< 20 ms) . This co cut-off . Consequ± 5.6 ms , 133 was± 5.6 ms , 132, anrtefacts . Nonethertefacts , 88 werertefacts . As expertefacts . These l2 mapping was expected to be sensitive for iron overload [P = 0.30). One study performed on 1.5 T and 3 T showed no statistically significant T2 changes in iron overload patients [2 values [2. The other studies showed a high correlation between T2 and T2* changes and significantly lower T2 values in patients with cardiac involved iron overload compared to healthy controls suggesting that T2 to could indeed be sensitive to iron overload [Furthermore, Toverload , howeverpatients , while o2 values , 93, 101overload , 93, 1012 values compared to healthy controls [1 mapping is the most sensitive CMR parameter in Anderson-Fabry disease and that Anderson-Fabry disease patients showed lower T1 values than controls regardless of LV function and morphology, and therefore T1 mapping is also sensitive to distinguish between controls and Anderson-Fabry disease patients without LVH [2 values in Anderson-Fabry disease patients compared to both HCM patients and healthy controls, suggesting that T2 mapping is also a sensitive CMR marker to early assess cardiac involvement in Anderson-Fabry disease patients without LVH [In Anderson-Fabry disease only patients with LVH showed significantly higher Tcontrols . Previouhout LVH . One stuhout LVH .2 values in DCM patients found in this meta-analysis confirmed the immunohistologal evidence of chronic myocardial inflammation for this disease [2 values of DCM subgroups seemed contradicting, since one study [2 values in severe DCM compared to mild DCM (P <  0.05), while another [2 values in severe DCM compared to mild DCM. Nevertheless, overall higher T2 values in DCM patients was confirmed by this meta-analysis.The higher T disease . Studiesne study  showed h another , though 2 values in the acute phase. All studies reported significantly higher T2 values except for one study that showed non-significantly higher T2 values in the acute phase compared to healthy controls, with 65.3 ± 45.4 ms and 53.7 ± 31.0 ms, respectively, which was mainly due to the broad SD of both groups [2 values in the acute phase, a follow-up study showed that 3 and 12 months after symptom onset the T2 values returned to normal [2 values at 189 days after symptom onset, and also showed that after 40 days the T2 values were still significantly higher compared to healthy controls, with 52.4 ± 1.0 ms and 50.4 ± 2.3 ms, respectively [2 mapping in myocarditis is most valuable in the acute phase in addition to the Lake Louise criteria that include histology and CMR with T1- and T2-weighted imaging.This meta-analysis including studies with myocarditis patients confirmed the expected higher Th groups . Aside fo normal . Anotherectively . These f2 values from HCM patients and controls showed significantly higher T2 values in patients [2* values from HCM patients with healthy controls, however their results were contradicting. One study at 1.5 T reported significantly lower T2* values in HCM patients compared to controls with 26.2 ± 4.6 ms and 31.3 ± 4.3 ms, respectively [2* values at 3 T for both hypertension patients with LVH (23.8 ± 3.1 ms) and without LVH (28.6 ± 4.2 ms) compared to healthy controls (30.8 ± 2.7 ms) [2 and T2* mapping. More research could enable to determine the clinical applicability of these mapping techniques, while T1 mapping has already shown to be promising in distinguishing hypertension related LVH and HCM [2 and T2* mapping of these risk populations is yet, and therefore we have to rely on the values of cardiac diseases without considering these risk factors.The single study that reported Tpatients . Two stuectively , whereasectively . Since eectively . Neverth 2.7 ms) . Based o and HCM , 206. Fuh LVH 23. ± 3.1 ms2 and T2* values of both patients and healthy controls demonstrate variation between studies related to differences in population demographics, CMR vendor, acquisition methods and analysis approach. This variation limits comparison between centers and therefore each center requires local T2 and T2* reference values to distinguish affected myocardium in cardiomyopathies from healthy myocardium. To this end reference values should be obtained in, preferably matched, healthy controls using the same CMR acquisition method as in patient care. Although similarities of changes in T2 and T2* values between cardiac diseases limits direct differentiation, this paper provides T2 and T2* mapping data which, together with other CMR parameters such as T1 mapping, ECV and LGE, can help to differentiate between cardiac disease entities.This meta-analysis showed that TAdditional file 1.Additional file 2: Figure 1. Weighted mean T2* values and weighted standard deviations (SD) of the sub-analysis in patients with myocardial infarction and iron overload measured at 1.5 T (A) and 3 T (B). In myocardial infarction, T2* values of remote myocardium (r) (grey square), infarct core (c) (black square) and infarct zone (z) (black triangle) are presented. In iron overload, the T2* value of iron overload patients (p) with cardiac involvement is presented. The number of included measurements for each population is reported above the graph. MI myocardial infarction, IO iron overload. Figure 2. Weighted mean T2 values and weighted standard deviations (SD) of the sub-analysis in patients with myocardial infarction, heart transplantation and myocarditis measured at 1.5 T (A) and 3 T (B). In myocardial infarction, T2 values of remote myocardium (r) (grey square), infarct core (c) (black square) and infarct zone (z) (black triangle) are presented. In heart transplantation, T2 values of heart transplant recipients with negative rejection (n) (grey square) and positive rejection (p) (black square) are presented. In myocarditis, T2 values of populations scanned in the non-acute phase (n) (grey square) and in the acute phase (a) (black square) are presented. The number of included subjects for each population is reported above the graph. MI myocardial infarction, Trans heart transplantation, MC myocarditis.


In cardiac amyloidosis (CA), amyloid infiltration results in increased left ventricular (LV) mass disproportionate to electrocardiographic (EKG) voltage. We assessed the relationship between LV mass–voltage ratio with subsequent heart failure hospitalization (HHF) and mortality in CA. Patients with confirmed CA and comprehensive cardiovascular magnetic resonance (CMR) and EKG exams were included. CMR-derived LV mass was indexed to body surface area. EKG voltage was assessed using Sokolow, Cornell, and Limb–voltage criteria. The optimal LV mass–voltage ratio for predicting outcomes was determined using receiver operating characteristic curve analysis. The relationship between LV mass–voltage ratio and HHF was assessed using Cox proportional hazards analysis adjusting for significant covariates. A total of 85 patients  were included, 42 with transthyretin and 43 with light chain CA. At a median of 3.4-year follow-up, 49% of patients experienced HHF and 60% had died. In unadjusted analysis, Cornell LV mass–voltage ratio was significantly associated with HHF  and mortality . Using ROC curve analysis, the optimal cutoff value for Cornell LV mass–voltage ratio to predict HHF was 6.7 gm/m2/mV. After adjusting for age, NYHA class, BNP, ECV, and LVEF, a Cornell LV mass–voltage ratio > 6.7 gm/m2/mV was significantly associated with HHF  but not mortality. Indexed LV mass–voltage ratio is associated with subsequent HHF and may be a useful prognostic marker in cardiac amyloidosis. Cardiac amyloidosis (CA) is a form of infiltrative cardiomyopathy in which misfolded amyloid proteins deposit within the myocardium, leading to progressive left ventricular hypertrophy (LVH), symptomatic heart failure (HF), cardiac arrhythmias, and death. The two most common proteins responsible for CA are transthyretin and immunoglobulin light chain. While previously thought to be a rare disorder, recent studies have demonstrated a high prevalence of CA in older patients with diastolic heart failure and low-flow, low-gradient aortic stenosis −4.Unlike other disorders associated with increased wall thickness, LVH in CA occurs due to abnormal protein deposition rather than myocyte hypertrophy. Therefore, patients with CA often have disproportionately high LV mass relative to electrocardiographic (EKG) voltage. While low voltage is classically described in CA, this finding has poor sensitivity and may be absent in up to half of cases . AdditioWe sought to assess the relationship between LV mass–voltage ratio and the risk of HF hospitalization (HHF) and mortality in CA. We hypothesized that increased LV mass–voltage ratio would be predictive of adverse events in this patient population. We chose cardiovascular magnetic resonance (CMR) as it is the gold-standard non-invasive test to quantify LV mass .We retrospectively studied 85 patients with cardiac amyloidosis who underwent comprehensive CMR exams and EKG between October 2010 and July 2019 at a single academic medical center. Patients were enrolled if they met the diagnostic criteria for cardiac amyloid which included a positive endomyocardial biopsy or a positive extracardiac biopsy with typical features of cardiac amyloidosis on cardiac imaging . TypicalClinical characteristics and comorbidities were established by review of the medical record. The following baseline clinical characteristics were collected: age, gender, ethnicity, height, weight, glomerular filtration rate (GFR), hematocrit, troponin, and brain natriuretic peptide (BNP). Information on comorbidities was queried from the medical chart including the presence of hypertension, diabetes, hyperlipidemia, and New York Heart Association (NYHA) Class. The Ohio State University Institutional Review Board approved this retrospective study and waived informed consent. This retrospective chart study involving human participants was in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.Electrical parameters were assessed from a standard 12-lead EKG. Left ventricular voltage was calculated utilizing the Sokolow, Cornell, and limb voltage criteria which have been previously utilized in cardiac amyloidosis . Steady-state free precession sequences (SSFP) were used for assessment of ventricular volumes, ejection fraction (EF) and LV mass. Ventricular volumes and EF were measured from contiguous short-axis cine images using semi-automated software for endocardial segmentation using endocardial and epicardial contours at end-systole and end-diastole with Simpson’s rule. LV mass was calculated from the total end-diastolic myocardial volume multiplied by the specific gravity of the myocardium (1.05 g/ml) . LV massLate gadolinium enhancement (LGE) imaging was performed using a gradient-echo inversion recovery sequence with magnitude and phase sensitive inversion recovery reconstructions 10 min after standard dose of gadolinium-based contrast agent . The preThe two co-primary outcomes, HHF and all-cause mortality, were assessed from the time of CMR as the first time point. HHF following CMR exam (regardless of any prior HHF) was identified by medical record review and defined as: physician documentation of HF along with symptoms  and physical signs  consistent with heart failure, and supporting clinical findings  with escalation in heart failure therapies . Vital sCategorical data are presented as frequency with percentage, and comparison between groups was done using the chi-square test or Fisher exact test as appropriate. The distribution of continuous variables was assessed using skewness, kurtosis and visual inspection of the histogram. Continuous variables are presented as mean ± standard deviation (SD) for normal distribution or expressed as median (interquartile range) for non-normal distribution. Continuous variables were compared between 2 groups by t test or Mann–Whitney U test, as appropriate. Analysis of variance (ANOVA) or Kruskal–Wallis test was used to compare differences among more than 2 groups for normally and non-normally distributed variables, respectively. The optimal cutoff value for indexed LV mass–voltage ratio and outcomes of mortality and HF hospitalization was determined using receiver operating characteristic (ROC) curve analysis . MultivaA total of 85 patients were included in the study . Clinical characteristics are summarized in Table 2 and mean left ventricular ejection fraction was 46.5 ± 14.2%. Mean native myocardial T1 was 1105 ± 80 ms and mean ECV was 51.8 ± 10.9%. Compared to those with light chain CA, patients with transthyretin CA had higher indexed LV mass and max wall thickness but lower ejection fraction. Patients with transthyretin CA also had significantly higher ECV when compared to those with light chain CA.CMR characteristics for the whole cohort and individual amyloid subsets are demonstrated in Table 2 respectively. There were no significant differences in LV mass–voltage ratio between the two amyloid subtypes by any of the three voltage criteria.The median time between EKG and CMR was 13 (2–35) days. Median voltage utilizing each of the criteria are presented in Table 2/mV. A total of 52 (61%) patients had indexed LV mass–voltage ratio ≥ 6.7 gm/mV/m2. An LV mass–voltage ratio using Cornell ≥ 6.7 gm/m2/mV was strongly associated with HHF after adjusting for clinical covariates   and mortality . After adjusting for age, BNP, NYHA class, ECV and LVEF, the Cornell LV mass–voltage ratio was independently associated with HF hospitalization  but not all cause mortality  Table . After eIn contrast, there was no significant independent association between LV mass–voltage by Sokolow  or limb voltage criteria  and HHF. Similarly, LV mass–voltage by Sokolow  or limb voltage criteria  was not associated with mortality in adjusted analysis.In this retrospective analysis, we report on the relationship between CMR-derived indexed LV mass–voltage ratio and clinical outcomes in patients with CA. We demonstrate a significant relationship between LV mass–voltage ratio and HHF even after adjusting for clinical covariates Fig. . LV massOf the voltage methods, LV mass–voltage ratio by Cornell voltage criteria had the closest association with HF hospitalization. Several sensitivity analyses were performed to evaluate the robustness of the primary efficacy results. The association between elevated indexed LV mass–voltage ratio and risk of HF hospitalization was consistent across all sensitivity analyses.The relationship between LV mass–voltage and clinical outcomes is not well described in CA. In a study by Cyrille et al., low voltage by Sokolow criteria was associated with a composite outcome of hospitalization, heart transplant or death . HoweverIn our study, we also demonstrated an association between LV mass–voltage ratio and mortality on univariate analysis. However, this relationship did not reach significance when multivariate analysis was performed. It is possible that our study was underpowered for this outcome. Larger cohorts may be needed to best study the relationship between LV mass–voltage ratio and death in CA.Based on our study, LV mass–voltage ratio as quantified by CMR appears to be a useful prognostic marker in patients with CA. Other CMR-derived markers including ECV and LGE have been consistently shown to predict adverse outcomes/survival in CA −29. HoweThis is a single center, retrospective study and results should be confirmed in a large multicenter cohort. Retrospective analysis was performed on patients referred for CMR thus introducing selection bias. Our study also lacked sufficient power to detect a difference in LV mass–voltage ratio and effects of treatment between transthyretin and immunoglobulin light chain CA. Lastly, ECV values were calculated from the mid short axis slice only as the basal T1 maps were not obtained at the time of the clinical scan, thus our data is representative of the mid-short axis slice.Indexed LV mass–voltage ratio as derived by CMR is associated with subsequent HF hospitalization. Indexed LV mass–voltage ratio may be a helpful prognostic marker in the care of patients with cardiac amyloidosis. Larger studies are needed to validate our findings, particularly in patients with less severe disease burden.


Micro-computed tomography (micro-CT) is a high-resolution imaging modality that provides accurate tissue characterization. Hypertrophic cardiomyopathy (HCM) occurs as a spontaneous disease in cats, and is characterized by myocardial hypertrophy, disarray and fibrosis, as in humans. While hypertrophy/mass (LVM) can be objectively measured, fibrosis and myocyte disarray are difficult to assess. We evaluated the accuracy of micro-CT for detection and quantification of myocardial disarray and fibrosis by direct comparison with histopathology. 29 cat hearts  underwent micro-CT and pathologic examination. Myocyte orientation was assessed using structure tensor analysis by determination of helical angle (HA), fractional anisotropy (FA) and myocardial disarray index (MDI). Fibrosis was segmented and quantified based on comparison of gray-scale values in normal and fibrotic myocardium. LVM was obtained by determining myocardial volume. Myocardial segments with low FA, low MDI and disruption of normal HA transmural profile on micro-CT were associated with myocardial disarray on histopathology. FA was consistently lower in HCM than normal hearts. Assessment of fibrosis on micro-CT closely matched the histopathologic evaluation. LVM determined by micro-CT was higher in HCM than normal hearts. Micro-CT can be used to detect and quantify myocardial disarray and fibrosis and determine myocardial mass in HCM. HCM is a common spontaneous cardiac disease of cats3, and the clinical and histopathologic features closely mimic those of the human disease4.Hypertrophic cardiomyopathy (HCM) is a myocardial disease characterized by a hypertrophied left ventricle (LV) in the absence of abnormal loading conditions9. Micro-CT has been shown to be highly accurate in cardiac phenotyping in both humans and mice10, with superior assessment of myocardial morphology and coronary artery anatomy compared with dissecting microscopy9. Iodine-enhanced micro-CT differentiates cardiac tissue types based on differential attenuation of X-rays11, and allows assessment of the orientation of aggregated myocytes in canine and human hearts12.Micro-computed tomography (micro-CT) is an imaging modality that enables high resolution imaging with three-dimensional (3D) micrometer resolution, and is used in the postmortem setting or for extracted organsThe capability of micro-CT to provide 3D virtual slicing of the whole heart allows an extensive cardiac assessment that has potential application as part of routine cardiac postmortem examinations. Micro-CT would be especially useful in conditions where lesions are irregularly distributed, as an imaging guide to tissue sampling, thereby improving on the diagnostic yield of conventional histopathology.15. Diagnosis of HCM can be challenging, as these cardinal features may be focal and do not necessarily match areas of LVH16, and therefore can be missed without extensive sampling15. Moreover, HCM is characterized by a spectrum of morphologic changes and a highly heterogeneous phenotype, with variable LVH distribution. Isolated LVH can be caused by HCM phenocopies, so accurate quantification of disarray and fibrosis is important for postmortem diagnostic accuracy.HCM has traditionally been diagnosed with histopathology based on the presence of 3 main features: left ventricular hypertrophy (LVH); myocardial disarray; and fibrosisOur aim was to evaluate the ability of micro-CT to detect the principal features of HCM by comparison with histopathology, and to explore the use of micro-CT to quantify myocardial fibrosis, myocyte disarray and LV mass (LVM).Twenty-nine hearts were included in the study . Mean scan duration was 75 min for the whole heart and 150 min for each LV section.Micro-CT mean cohort voxel size was 24 µm for the whole heart and 16 µm for the LV section scans. LVM determination was possible in 28/28 available whole heart scans. Quantification of LV fibrosis was performed in 13/17 HCM hearts, as poor myocardial detail in 4/17 scans hindered accurate fibrosis segmentation. Analysis of the orientation of aggregated myocytes was possible in 16/29 hearts, with inadequate image quality precluding analysis in the remaining hearts. The cause for reduced image quality on micro-CT in these hearts was unclear.Actual LVM from 13 hearts  was greater (7.4 ± 2.5 g) than LVM obtained from M1-Fiji (5.9 ± 2.1 g) or M2-Imaris (6.0 ± 2.2 g), p < 0.0001. Both micro-CT methods yielded LVM values that were consistently lower than aLVM, with an average bias of 1.5 g and 95% limits of agreement between 0.08–3.0 (M1-Fiji) and 0.05–2.8 (M2-Imaris). LVM (M2-Imaris) was greater (7.8 ± 2.6 g) in 16 HCM hearts than in 12 normal hearts (4.9 ± 1.1 g), p = 0.001.Micro-CT images of the LV section datasets were matched to the corresponding histology slide stained with Masson’s trichrome. Replacement myocardial fibrosis on histology appeared as hypodense areas on micro-CT images Fig. , allowin3 [0.27–7.1] and 22.8 mm3 [10.1–40.6] respectively (p = 0.003). In LV section T2, 8 hearts had absent or mild fibrosis and 4 had moderate fibrosis, which corresponded to fibrosis volumes of 0.11 mm3 [0–1.2] and 69 mm3 [13.3–99.3], respectively (p = 0.004). In LV section T3, 7 hearts had absent or mild fibrosis and 4 moderate or severe fibrosis, with fibrosis volumes of 0.01 mm3 [0–1.4] and 46 mm3 [1.7–227], respectively (p = 0.006) . Mean volume of fibrosis determined in the whole LV of 13 HCM hearts was 9.5 mm3 [1.3–1184].Replacement fibrosis in the LV section T1 was classified as absent or mild in 9 hearts, and moderate in 4 hearts based on histopathology. The corresponding median fibrosis volume determined by micro-CT was 1.47 mm3 0.7–7.1 andThe HA, FA, MDI and percentage of circumferentially arranged myocytes were determined in the LV T2 sections of 16 hearts . T2 section colored maps of the different orientation variables were matched to the corresponding histology slide. Myocardial segments with low FA, low MDI and loss/disruption of the normal HA transmural profile on HA plots corresponded to areas of myocardial disarray on histology Fig. .Figure 3Overall FA distribution in the LV T2 section and across each of the 5 LV segments was different between normal and HCM hearts Fig. . FA distThe overall HA distribution was similar between groups across the T2 section and 5 LV segments, although the mean HA transmural profiles differed between normal and HCM hearts in the endocardial/sub-endocardial area of the septum and the epicardial/sub-epicardial area in the posterior-septal, posterior, posterior-lateral and lateral LV segments  included residual blood clots in the ventricular chamber, epicardial fat, and the mitral and aortic valves, which were excluded from the ROIs defined to calculate LVM on micro-CT and could potentially account for the observed differences. Although micro-CT methods yielded consistently lower LVM values, micro-CT still correctly differentiated normal from HCM hearts based on LVM, and is a potentially useful imaging tool for postmortem LVM estimation.15. In our micro-CT scans, replacement fibrosis was readily identified as hypodense areas. Iodine is believed to enhance myocardial contrast in postmortem specimens by becoming immobilized within glycogen in myocytes, which causes a greater X-ray attenuation of myocardium than fibrous tissue18. Fibrous tissue is therefore seen as darker areas on micro-CT (hypodense). Conversely, with in vivo clinical MRI and CT imaging, iodinated contrast agents accumulate in areas of fibrosis, as there is increased extracellular space due to myocyte loss. By retaining contrast, fibrotic areas are therefore seen with higher density/intensity in clinical CT/MRI20, which is the opposite of what is seen with micro-CT. As with clinical CT, we were not able to detect interstitial fibrosis with micro-CT20. Even with MRI, late gadolinium enhancement mainly detects replacement fibrosis19. The quantitative assessment of replacement fibrosis on micro-CT closely matched the semi-quantitative histopathologic evaluation.HCM is typically characterized by interstitial and replacement fibrosis13. The orientation of aggregated myocytes has been previously assessed with micro-CT, high-resolution episcopic microscopy (HREM) or Synchrotron imaging using structure tensor analysis (STA)23. In our study the voxel resolution was sufficient for determination of the orientation of aggregated myocytes by STA. Areas of disorganized myocytes on micro-CT corresponded to myocardial disarray on histology, and we were able to differentiate HCM from normal hearts based on their myocyte orientation , but intra-observer variability was not assessed.Our study showed that postmortem micro-CT imaging can detect and quantify the cardinal pathologic features of HCM, including myocardial disarray, which is difficult to quantify with conventional histopathology. Micro-CT therefore has potential value in the postmortem diagnosis of HCM, either as a stand-alone diagnostic modality or as a method of identifying focal lesions to allow targeted sampling for conventional histopathology.This study was approved by the institutional ethical review board of the Royal Veterinary College . The clinical procedures of euthanasia and postmortem examination were done under the Veterinary Surgeons Act as part of recognised veterinary practice. The owners provided informed consent to use the heart tissue obtained for research purposes. The College’s Clinical Research Ethical Review Board scrutinised the consent form and information given to the owner about the project, ensuring they were fully informed of the research to be conducted on tissues obtained at postmortem. This was a prospective observational postmortem study. Ex vivo isolated feline heart specimens were evaluated by micro-CT at Great Ormond Street Hospital (GOSH), and gross and histopathology examinations were performed by a board-certified veterinary pathologist as the gold standard.All samples were from pet cats that had died or been euthanized for medical reasons with owner-informed consent. The control group consisted of normal hearts from cats undergoing routine necropsy by the RVC Pathology Service. The HCM group consisted of hearts from clinical cases of HCM diagnosed by veterinary cardiologists.2KI) with a tissue:volume ratio of 1:30 at room temperature for > 48 h11. After iodination, the hearts were washed in water to remove surface contrast medium and towel-dried.The hearts were promptly excised after natural death or euthanasia with IV pentobarbital sodium, and gently flushed with water to remove clots. Hearts were fixed in 10% formaldehyde solution at a tissue:volume ratio of 1:20 for > 48 h, then weighed before immersion in 2.5% potassium tri-iodide . The hearts were wrapped with parafilm M  and mounted on a low-attenuation carbon fiber rod to minimize artifacts caused by movement and dehydration during the scan.One micro-CT scan of the whole heart was obtained followed by scans of 3 transverse sections of the LV. After the initial whole heart scan, the hearts were sectioned longitudinally to correspond with a long-axis 5-chamber echocardiographic view, and 4 transverse ventricular sections were made at 5 mm intervals from the level of the atrioventricular groove to the apex in one half of the heart   and post-processed using VGSTUDIO MAX . Whole heart and LV sections micro-CT scans were reconstructed isotropically. Transverse and longitudinal ‘virtual’ dissections were created from the whole heart scans, corresponding with short-axis and long-axis echocardiographic planes, respectively. This resulted in transverse and longitudinal image stacks of an average of 1485 images per stack for the whole heart scans, and 565 images for each LV section stack. Isotropic voxel sizes ranged between 19 and 24 µm for the whole heart scans and 13–21 µm for the LV sections. All micro-CT data sets were initially viewed using VGSTUDIO MAX and Fiji (2.0.0-rc-67/1.52c) for assessment of image quality and evaluation of cardiac morphology.The 3 main pathologic characteristics for HCM diagnosis  were evaluated using the micro-CT data and compared between normal and HCM hearts. The results were compared with gross pathology and histopathology.Whole heart scan datasets were imported into Fiji as a data sequence and viewed as an image sequence and in 3D. The LV region of interest (ROI) was segmented using short-axis reconstructions of the whole heart scans by manually tracing the endocardial and epicardial borders of the LV myocardium in 1 slice every 5–10 slices using the ’brush’ tool. The most basal slice (defined as the first basilar slice where LV myocardium was present) and the most apical slices (where no intracavitary blood was present) were also included in the mass calculation by tracing only the epicardial border. Papillary muscles and LV trabeculations were included in the ROI and therefore in the LVM calculation. The slices between the manually traced segmentations were automatically traced by applying the interpolation function. In each case, 3D reconstructions of the ROIs (LV segmentation) were created to assess whether segmentation was adequate. LV segmentation for determination of LVM by micro-CT was performed by a single observer (JNM).27.LVM was initially calculated in 13 representative hearts by micro-CT using 2 different methods and each compared with the actual LVM (aLVM) obtained by weighing the hearts. The method with better agreement with aLVM was then used for subsequent LVM determination. Method 1 (M1-Fiji) used the open source image processing software, Fiji, to calculate the LV volume by multiplying the area of each LV slice by voxel size and sum the volumes of all slices. Method 2 (M2-Imaris) used the software package Imaris (Bitplane AG), to calculate surface area and volume from 3D reconstructions of the LV (automated software). LVM was obtained in both methods by multiplying total LV volume by myocardial density (1.05 g/ml)28, but as the studied hearts were stained with iodine, myocardial density was assessed to determine whether iodine had changed the tissue density. Twelve cubes of LV myocardial tissue (≈ 4 mm) without endocardial and epicardial surfaces, as described28, were cut from 2 different hearts. The volume of each myocardial section was calculated by water displacement method using a graduated cylinder and its mass measured in a digital balance. Myocardial density was calculated as mass/volume. The LV myocardial density in 12 sections of iodinated hearts was 1.05 (SD 0.15) g/ml.Myocardial density is typically assumed to be 1.05 g/mlActual LVM (aLVM) was determined after the initial micro-CT scan by weighing the LV after dissecting the great vessels, atria and right ventricular free wall. The LV was then weighed 5 times on a digital balance and the mean defined as aLVM.LV myocardial fibrosis was quantified in the HCM whole heart and LV section micro-CT datasets. In the LV sections, the micro-CT results were compared with the histologic assessment.5 based on variation in gray-scale values between normal and fibrotic tissue. A preliminary visual inspection of micro-CT images and their equivalent histologic LV transverse sections showed that hypodense areas in micro-CT appeared to correspond with fibrosis on histology, reflecting different X-ray attenuation between normal myocardium and fibrosis. Hypodense areas of similar gray-scale values across the entire specimen were considered to represent fibrosis and were segmented and quantified by a semi-automated region growing method by image processing software (Imaris)5. The ‘magic wand’ tool was used to manually segment the ROI (hypodense/fibrotic areas) in each 10th slice from LV base to apex in the whole heart scans and from the first to last slice in the LV section images. Segmentation tools combined the manually segmented areas by intensity of pixels (voxels) creating a 3D surface, and the volume of the 3D reconstruction representing fibrosis was calculated . The datasets were viewed and cropped in Fiji, then imported to Seg3D (v2.4.0 RC 3) for semi-automated LV segmentation, excluding the right ventricle and papillary muscles. Only the LV walls were included in the orientation calculations.23. Briefly, image intensity gradient in x, y and z directions was calculated for each image voxel using a central difference algorithm. The structure tensor was obtained as the cross product of gradient vectors. Eigen-decomposition was then applied to the structure tensor to obtain the three eigenvalues  and eigenvectors . The vector aligned with the long axis of myocytes was that with the smallest eigenvalue , representing the direction with least intensity variation. The helical (or inclination) angle (HA) of the aggregated myocytes was calculated as the angle between the tertiary eigenvector (v3) and the local circumferential plane defined by the local transmural and circumferential directions , myocardial disarray index (MDI) and percentage of circumferential arranged myocytes23.A gradient structure tensor method implemented in Matlab  was used to assess the orientation of aggregated myocytes in a mid-LV slice (section T2) as previously describedFA was calculated as:24. Similarly to DT-MRI, FA calculated from the structure tensor quantifies the degree of anisotropy in the direction of aggregated myocytes. FA values close to 1 reflect myocytes aligned in the same direction, while values near 0 represent myocytes arranged in random directions.In diffusion tensor MRI (DT-MRI), FA quantifies the degree of water diffusion anisotropy. FA values range between 0 and 1, where values close to 1 represent ‘restricted water diffusion’ and values near 0 represent ‘unrestricted diffusion’3) within a neighborhood that consists of the voxel itself and its nearest neighbors23. The computation of MDI was performed using a ROI of 15 × 15 × 15 voxels with values ranging from 0 to 1. A MDI value close to 1 at a given voxel indicates that the myocardial disarray is negligible in the neighborhood of this voxel, whereas values of MDI close to 0 denote a high degree of myocardial disarray  of the longitudinal direction of aggregated myocytes, represented by the tertiary eigenvector  was assessed in the whole T2 LV section and in 5 different LV segments (ROIs): septal, posterior-septal, posterior, posterior-lateral and lateral  myofibers. It may run in multiple directions, with a haphazard arrangement, may isolate and entrap individual myofibers if more severe, or be present as uninterrupted fibrosis. It tends to be more focal/multifocal. Histopathologic lesions of replacement fibrosis were scored as mild, moderate or severe using a semi-quantitative scoring system  associated with LVH and myocyte hypertrophy, myocardial disarray and interstitial/replacement fibrosisem Table . Areas oHistologic comparisons with micro-CT findings were performed by comparing micro-CT images of each LV section with the corresponding histology section. LV section scan datasets (T1–T3 of each heart) were imported into Fiji and viewed as a sequence of images to match the histology section as closely as possible  and non-normally distributed data as median [range]. Comparisons between aLVM, M1 and M2 were made by repeated-measures ANOVA with Tukey’s post-hoc test. Bland–Altman analysis was used to assess agreement between LVM determined by micro-CT and aLVM.2) compared between normal and HCM groups.The association between volume of fibrosis determined by micro-CT and the semi-quantitative histologic assessment of fibrosis was done by comparing micro-CT fibrosis values between histology groups (absent/mild vs moderate or absent/mild vs moderate/severe) in each LV section  by Mann–Whitney U-test. Median fibrosis volume between the 3 LV sections was compared by Friedman test with Dunn’s post-hoc test. Pearson’s correlation coefficient was performed to assess the association of FA and MDI with heart weight, aLVM and fibrosis. HA, FA and MDI were compared between normal and HCM hearts as the mean in each LV segment and whole LV T2 section. The distribution of values of HA, FA and MDI at each LV segment was also assessed, with differences across segments  between normal and HCM groups tested using a two-sample Kolmogorov–Smirnov test. The FA and MDI values were compared between groups for the whole LV T2 section by Students’ independent t-test, and between each of the 5 LV segments by repeated measures ANOVA. The latter was run for each variable (FA and MDI) including group, segment and their interaction in the model with LSD post-hoc test. The mean HA transmural profiles for normal and HCM groups were compared at each relative position across the LV wall for each LV segment by Mann–Whitney U-test. A linear regression fitting of the HA transmural profiles at each LV segment was also performed and the slope (B1) and linearity  and GraphPad Prism 7.Supplementary Information.


Objective: To explore microstructural and cerebral blood flow (CBF) abnormalities in individuals with subjective cognitive decline plus (SCD plus) using diffusional kurtosis imaging (DKI) and three-dimensional (3D) arterial spin labeling (ASL).Methods: Twenty-seven patients with SCD plus, 31 patients with amnestic mild cognitive impairment (aMCI), and 33 elderly controls (ECs) were recruited and underwent DKI and 3D ASL using a GE 3.0-T MRI. Mean kurtosis (MK), fractional anisotropy (FA), mean diffusivity (MD), and CBF values were acquired from 24 regions of interest (ROIs) in the brain, including the bilateral hippocampal (Hip) subregions , posterior cingulate cortex (PCC), precuneus, dorsal thalamus subregions , lenticular nucleus, caput nuclei caudati, white matter (WM) of the frontal lobe, and WM of the occipital lobe. Pearson's correlation analysis was performed to assess the relationships among the DKI-derived parameters, CBF values, and key neuropsychological tests for SCD plus.Results: Compared with ECs, participants with SCD plus showed a significant decline in MK and CBF values, mainly in the Hip head and PCC, and participants with aMCI exhibited more significant abnormalities in the MK and CBF values than individuals with ECs and SCD plus in multiple regions. Combined MK values showed better discrimination between patients with SCD plus and ECs than that obtained using CBF levels, with areas under the receiver operating characteristic (ROC) curve (AUC) of 0.874 and 0.837, respectively. Similarly, the AUC in discriminating SCD plus from aMCI patients obtained using combined MK values was 0.823, which was also higher than the combined AUC of 0.779 obtained using CBF values. Moreover, MK levels in the left Hip (h) and left PCC positively correlated with the auditory verbal learning test-delayed recall (AVLT-DR) score in participants with SCD plus. By contrast, only the CBF value in the left Hip head positively correlated with the AVLT-DR score.Conclusions: Our results provide new evidence of microstructural and CBF changes in patients with SCD plus. MK may be used as an early potential neuroimaging biomarker and may be a more sensitive DKI parameter than CBF at the very early stage of Alzheimer's disease (AD). Subjective cognitive decline (SCD), the first clinical manifestation in the Alzheimer's disease (AD) continuum, refers to a self-experienced cognitive capacity decline and has been shown to be associated with a high risk of conversion to AD , developed based on diffusion tensor imaging (DTI), can provide additional metrics related to the non-Gaussianity of water diffusion, such as mean kurtosis (MK), axial kurtosis, and radial kurtosis  ASL imaging measured in multiple brain regions to determine how these regions are altered in this stage. Additionally, we also assessed the relationships between DKI-derived parameters, CBF values, and key neuropsychological test scores among patients with SCD plus.Ninety-one participants were recruited for this study from September 2017 to July 2019, including 27 patients with SCD plus, 31 patients with aMCI, and 33 age- and sex-matched ECs. The SCD plus and aMCI groups were recruited from the outpatient clinic, and ECs were recruited through a medical examination center. Before enrollment, written informed consent was obtained from all participants or their legal guardians. The study was approved by the Ethical Committee of Second Affiliated Hospital of Shantou University Medical College (Registration No. 2017-10), and all procedures were performed in accordance with the Declaration of Helsinki. All participants provided their demographic and clinical data  and had undergone cognitive evaluations by two expert neurologists. All participants had also undergone a series of standardized neuropsychological evaluations, including tests that measured cognitive functioning in the domains of memory, executive functioning, attention, and language. The basic set of psychological tests included the Mini-Mental State Examination . Next, we changed the host scanning method from the clinical mode to the research mode. Using the research mode, DKI scanning parameters were obtained using an echo-planar imaging (EPI) sequence as follows: repetition time (TR)/echo time (TE) = 6,000 ms/109 ms; diffusion gradient pulse duration = 32.2 ms; diffusion gradient separation = 38.8 ms; slice thickness = 4 mm; slice gap = 0 mm; field of view (FOV) = 240 × 240 mm; matrix = 256 × 256; number of excitations (NEX) = 1; http://www.nitrc.org/projects/dke/). Quantitative MK, FA, and MD maps were generated from the DKI model with b-values = 0, 1,000, and 2,000 s/mm2 by the following equation:All raw DKI images were transferred to a GE Advantage Workstation version 4.6  and post-processed in the FuncTool software package 9.0 environment. Before DKI parametric maps were generated, all raw data were automatically performed with the affine and rigid body registrations to the B0 image for reducing EPI distortion, eddy-current distortion, and head motion. Next, the DKI parameters, including MK, FA, and MD, were automatically generated by the DKI software, which was developed using the Applied Science Laboratory of GE (Sn(b),  represents the diffusion encoding direction n and diffusion signal intensity for diffusion weighting b, and S0 represents the signal intensity for minimally diffusion-weighted imaging (b0).Dij and Wijkl represent the components of the diffusion and kurtosis tensors, respectively. A description of the DKI analysis method can be found in our previous studies  in the FuncTool environment. The CBF values were reacquired before the quality control step as follows. First, a high level of background suppression was used to suppress the surrounding static tissue around the pseudocontinuous labeling pulse. Second, motion correction, temporal and spatial filtering, and partial volume effect correction were performed. Subsequently, the CBF values were calculated by intensity normalization. A quantitative CBF map was generated based on the following equation:1b represents the T1 relaxation time of the blood, T1g represents the T1 relaxation time of the GM, tsat represents the duration time of the saturation pulse performed before imaging, α represents the labeling efficiency, λ represents the brain/blood partition coefficient, τ represents the labeling duration, and ω represents the post-labeling delay time. In addition, CBF analysis has been described in previous studies  in the brain were mainly obtained from 24 regions using mirror symmetry tools  derived from FuncTool software, as shown in Regions of interest (ROIs) were carefully delineated and analyzed by two independently experienced neuroradiologists who were blinded to the status of the subjects with B0 images as references. Each ROI was selected on the maximum level of the structures that were best demonstrated according to each corresponding parametric map. When the ROIs were placed, we also tried to avoid major vascular structures, cerebrospinal fluids, and interhemispheric regions. To ensure that the same locations were extracted from each subject, the ROIs (the ROI areas ranged from 18 to 22 mmhttps://www.graphpad.com/scientific-software/prism). Sex distributions were analyzed using the chi-squared test among the three groups. One-way ANOVA was used to assess age, education, imaging metrics, and neuropsychological test results among patients with SCD plus, patients with aMCI, and ECs. ANOVA with false discovery rate (FDR) correction as described by the Benjamini–Hochberg method was used to compare the DKI parameters and CBF values using the R soft package  among three groups to compare the symmetrical ROIs in the left and right cerebral hemisphere, respectively. The non-parametric Kruskal–Wallis test was used if the data were not normally distributed. Pearson's correlation analysis was used to evaluate the relationship between the measured parameters and the key neuropsychological scores for SCD plus controlled for age, sex, and the education level as nuisance covariates. The measured neuroimaging parameters were determined by receiver operating characteristic (ROC) curve analysis to evaluate the diagnostic accuracy. To determine the predictive accuracy of the parameters in discriminating patients with SCD plus from patients with aMCI or ECs, the area under the ROC curve (AUC) was calculated to assess the diagnostic ability of the imaging metrics, both alone and in combination. Combined AUC values were obtained by binary logistic regression. All data were expressed as means ± SD, and the values of p < 0.05 were considered statistically significant.Statistical analyses were performed using Statistical Package for Social Science version 25.0  and GraphPad Prism software 8.3.0 , Hip (b), Hip (t), PCC, Pr, DT (a), DT (vl), DT (m), LN, CNC, FLWM, and OLWM among the three groups . SupplemCompared with the ECs, participants with SCD plus had significantly lower MK values in the bilateral Hip (h), left PCC, left DT (a), and left OLWM. Decreased CBF values were also found in the left Hip (h) and bilateral PCC. However, the MK and CBF values were increased in the left Pr. The FA value was decreased only in the left OLWM. No significant MD changes were found in any ROI between the two groups.Compared with ECs, participants with aMCI had a lower level of MK in the bilateral Hip (h), left Hip (b), bilateral PCC, bilateral DT (a), left DT (vl), bilateral OLWM, and left CNC. Similarly, the level of CBF was decreased in the bilateral Hip (h), bilateral PCC, bilateral DT (a), left OLWM, left CNC, and left FLWM. The FA levels were also decreased in the bilateral PCC, left Pr, bilateral OLWM, and bilateral FLWM. Additionally, the MD values were elevated in the left Hip (h), left PCC, left DT (a), and left OLWM. No significant differences in the MD values were found in any right ROIs between the two groups.Compared with participants with SCD plus, patients with aMCI had lower MK levels in the bilateral PCC and left Pr. Decreased FA values in the right OLWM along with the CBF levels in the left Pr and the left DT (a) were also observed. No significant differences were found in the MD values in any ROIs, the FA values in the left ROIs, or the CBF levels in the right ROIs between the two groups.r = 0.423; p = 0.028) and in the left PCC   only in the left Hip (h)  had the best group discriminability, with an AUC of 0.768 (95% CI: 0.648–0.887) for the “SCD plus vs. ECs” comparison, while the CBF value in the left Pr had the best group discriminability, with an AUC of 0.751 (95% CI: 0.629–0.874) for the “SCD plus vs. aMCI” comparison. However, based on the combined AUC analysis method, the combined AUC  in discr Hip (h) . No signSubjective cognitive decline is known to be pervasive in elderly individuals older than 65 years (~25–56%), and approximately half of them remain cognitively stable   and PCC were observed in patients with SCD plus. A correlation only between the AVLT-DR scores and CBF values was observed in the left Hip. We assumed that the decreased MK/CBF in the left Hip (h) may be crucial for progressive memory impairment. Our correlation results also support the possibility that changes in MK are the strongest predictor of cognitive impairment scores, particularly in the very early stage of AD.Several limitations of this study should be noted. First, as a cross-sectional study, few SCD plus patients were included. The sample size should be increased, and a longitudinal study of this study population is needed to identify early neuroimaging biomarkers for the prediction of AD. Second, patients with AD were not included in our study; therefore, the continuous spectrum of AD could not be fully explored. Further research should be designed with more participants to assess the distinction among SCD plus converters, SCD plus non-converters, and probable AD. Third, the inclusion criteria for SCD plus were based on the number of SCD plus features met; typically, patients are expected to meet more than three  and PCC appear to represent an optimal, effective, and potentially useful non-invasive disease biomarker of the preclinical phase of AD.The original contributions presented in the study are included in the article/The studies involving human participants were reviewed and approved by the Ethical Committee of Second Affiliated Hospital of Shantou University Medical College (Registration No. 2017-10). The patients/participants provided their written informed consent to participate in this study.ZY, YR, and ZC: designed the study and collected the data. YR, YW, and ZC: collected the data. XZ, QX, and ML: performed the statistical analysis. ZY and YL: conceived and designed the experiments and prepared the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.