Cardiac Magnetic Resonance Features Research Articles

CMR characterisation of patients with heart failure and left bundle branch block

Abstract Introduction Cardiac magnetic resonance (CMR) is recommended internationally for tissue characterisation, volumetric assessment and assessment of prior myocardial infarction (1). Patients with left bundle branch block (LBBB) form a significant sub-group of individuals, however, there is limited data available to accurate determine whether LBBB is associated with any CMR-definable phenotypes. Aim We aimed to identify the distinctive cardiac magnetic resonance (CMR) features of patients with left bundle branch block (LBBB) and heart failure with reduced ejection fraction (HFrEF) of presumed non-ischaemic aetiology. Methods Participants from the MATCH (MyocArdial Tissue CHaracteristics in patients with heart failure according to glycaemic status) registry were prospectively enrolled. Exclusion criteria included: LVEF >40% at initial evaluation, established diagnosis of coronary artery disease, known presence of structural heart disease, suspected myocarditis, congenital heart disease and significantly impaired renal function. Following identification of HF, guideline-directed medical therapy was initiated based on the decision of the treating physician. LV recovery was defined as achieving ≥10% absolute improvement to a level of 40% or greater of LVEF from baseline evaluation upon the date of CMR quantification. Electrocardiograms were analysed to establish the presence or absence of LBBB. Results A total of 391 patients were recruited including 115 (29.4%) presenting with LBBB. Compared to controls, LBBB patients exhibited larger left ventricles and smaller right ventricles, but no differences were observed with respect to LVEF (35.8±12 vs. 38± 12 %, p=0.105) or right ventricular ejection fraction (RVEF). The prevalence of ischaemic scar (18.3% vs 21%, p=0.54), non-ischaemic fibrosis (25.2% vs 32.6%, p=0.15) and inducible ischaemia (6.1% vs. 7.6%, p=0.6) was comparable in patients with LBBB and those without. The overall rate of LV recovery was not significantly different between LBBB and non-LBBB patients (27.8% vs. 33%, p=0.32) from their baseline evaluation to the time of CMR assessment (70 [42 - 128] days). In the multivariate logistic regression, reduced LVEF remained an independent predictor of LV non-recovery in patients with LBBB, even after adjusting for gender and QRS duration (OR 0.93, 95%CI 0.87 – 0.99, p=0.03). In contrast, this association was not observed among patients without LBBB, whereas ischaemic scar was the primary predictor of LV non-recovery (OR 4.31, 95%CI 1.85 – 10.04, p=0.0007). Conclusion In this study patients presenting with a combination of HFrEF and LBBB had a larger LV cavity and smaller RV cavity than those without LBBB. However, there were no differences in the prevalence of ischaemic scar, non-ischaemic scar of inducible ischaemia according to the presence of absence of LBBB. Rates of LV recovery were similar between LBBB and non-LBBB patients.Clinical CMR ParametersSegmental Distributions

Enhancing the selection of heart failure patients for invasive procedures: how machine learning can predict the diagnostic yield of endomyocardial biopsy

Abstract Background Determining the etiology of heart failure (HF) is crucial for appropriate treatment. Endomyocardial biopsy (EMB) is an invasive procedure that complements clinical assessment and imaging in diagnosing various cardiac disorders. The diagnostic value of EBM depends upon the anticipated yield of the procedure. Whether results from non-invasive examinations may predict the diagnostic yield from EMB is unclear. Purpose We aimed to investigate the relative importance of clinical and instrumental features in predicting a diagnostic EMB result, using a machine learning (ML) approach. Methods We retrospectively examined 665 consecutive adult patients with HF symptoms who underwent right EBM as part of their diagnostic work-up. The primary outcome was a positive biopsy result with a clear diagnosis. The ML algorithm consisted of Gradient Boosting Machines (GBM), with computation of relative variable importance using conditional importance. We calculated the conditional variable importance for 53 clinical or instrumental variables. Model performance was evaluated using a receiver operating characteristic curve, which was compared to a logistic regression model using the same variables. Validation was performed using a 10-fold cross-validation model. Results Among the 665 patients (50±14 years, 67% male), the EMB provided a diagnosis in 138 cases (20.8%). Patients attaining diagnosis were more often older, had a shorter disease duration, presented with ventricular arrhythmia or cardiac arrest, had a pacemaker or defibrillator, displayed higher creatinine, NT-proBNP and high-sensitive troponin T levels, and had smaller ventricular volumes with higher ejection fraction at CMR. All patients with a diagnostic EMB showed late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) in the right ventricle, the right atrium or in the left atrium. The relative importance of different variables predicting outcomes is presented in Figure 1. The top six included four distinct CMR features and two circulating biomarkers (NT-proBNP and high-sensitive troponin T). LGE in the right ventricle and the presence of left ventricular hypertrophy were stronger predictors compared to the remaining variables. The GBM model performed significantly better than the logistic regression model (AUC GBM 0.98, AUC logistic regression 0.93, DeLong’s test p<0.001) (Figure 2). Conclusion Using a ML algorithm, CMR LGE, left ventricular hypertrophy, and elevated cardiac biomarkers, stand out as strong overall predictors of an endomyocardial biopsy with a high diagnostic yield.Figure 1Figure 2

Imminent risk of LVEF decline in asymptomatic patients with primary mitral regurgitation.

2020 American College of Cardiology/American Heart Association (ACC/AHA) Guidelines state that the ideal time for mitral valve surgery in primary mitral regurgitation (PMR) is when the LV approaches but has not yet reached echocardiographic LV ejection fraction (EF) < 60% or LV end-systolic dimension (ESD) > 40 mm. However, it is difficult to know the imminent risk of crossing this threshold when the surgical outcome is less optimal. Using machine learning and statistical models, we have shown that cardiac magnetic resonance (CMR) LV sphericity index (SI) and LV mid circumferential strain rate (SRcirc) added to LVEF and LVESD predict LVEF < 50% after mitral valve surgery. Here we test the hypothesis that these CMR features predict LVEF < 60% in asymptomatic PMR patients at 18 months. 33 asymptomatic PMR patients with moderate to severe mitral regurgitation had CMR with tissue tagging at baseline and every 6 months for 18 months. Two types of models were employed to predict LVEF < 60% at 18 months: a model using CMR features at a single time point (e.g., baseline) and a model utilizing repeated measurements over time. CMR LVEF decreased below 60% in 13 patients over 18 months. LVEF varied over time with an inverse relation to mean arterial pressure and mean end-systolic wall stress. Random Forest models utilizing LV SI, LV mid SRcirc, LVESD, and LVEF at a single time point (baseline) had a predictive accuracy of 64%. LV SI, LV mid SRcirc, LVESD and LVEF at baseline, 6, and 12 months achieved a higher predictive accuracy of 79%, improved sensitivity from 57% to 85% than baseline alone and identified a threshold of CMR LVEF 63%-64% signaling LVEF < 60%. The variability of LVEF due to blood pressure dependence may require a longitudinal study that incorporates LVEF, LVESD, SRcirc at multiple time points to identify the threshold at which LVEF is at risk for decline to less than 60%.

Role of advanced CMR features in identifying a positive genotype of hypertrophic cardiomyopathy

BackgroundHypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disease that affects approximately one in 500 people. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool for the non-invasive assessment of HCM. CMR can accurately quantify the extent and distribution of hypertrophy, assess the presence and severity of myocardial fibrosis, and detect associated abnormalities. We will study basic and advanced features of CMR in 2 groups of HCM patients with negative and positive genotype, respectively. Materials and methodsThe study population consisted in consecutive HCM patients referred to Centro Cardiologico Monzino who performed both CMR and genetic testing. Clinical CMR images were acquired at 1.5 T Discovery MR450 scanner (GE Healthcare, Milwaukee, Wisconsin)) using standardized protocols T1 mapping, T2 mapping and late gadolinium enhancement (LGE). Population was divided in 2 groups: group 1 with HCM patients with a negative genotype and group 2 with a positive genotype. ResultsThe analytic population consisted of 110 patients: 75 in group 1 and 35 patients in group 2.At CMR evaluation, patients with a positive genotype had higher LV mass (136 vs. 116 g, p = 0.02), LV thickness (17.5 vs. 16.9 mm), right ventricle ejection fraction (63 % vs. 58 %, p = 0.002).Regarding the LGE patients with positive genotype have a higher absolute (33.8 vs 16.7 g, p = 0.0003) and relative LGE mass (31.6 % vs 14.6 %, p = 0.0007). On a segmental analysis all the septum (segments 2, 8, 9, and 14) had a significantly increased native T1 compared to others segments. ECV in the mid antero and infero-septum (segments 8 and 9) have lower values in positive genotype HCM. Interestingly the mean T2 was lower in positive genotype HCM as compared to negative genotype HCM (50,1 ms vs 52,4). ConclusionsOur paper identifies the mid septum (segments 8 and 9) as a key to diagnose a positive genotype HCM.

Machine Learning in Hypertrophic Cardiomyopathy: Nonlinear Model From Clinical and CMR Features Predicting Cardiovascular Events

BackgroundThe cumulative burden of hypertrophic cardiomyopathy (HCM) is significant, with a noteworthy percentage (10%-15%) of patients with HCM per year experiencing major adverse cardiovascular events (MACEs). A current risk stratification scheme for HCM had only limited accuracy in predicting sudden cardiac death (SCD) and failed to account for a broader spectrum of adverse cardiovascular events and cardiac magnetic resonance (CMR) parameters. ObjectivesThis study sought to develop and evaluate a machine learning (ML) framework that integrates CMR imaging and clinical characteristics to predict MACEs in patients with HCM. MethodsA total of 758 patients with HCM (67% male; age 49 ± 14 years) who were admitted between 2010 and 2017 from 4 medical centers were included. The ML model was built on the internal discovery cohort (533 patients with HCM, admitted to Fuwai Hospital, Beijing, China) by using the light gradient-boosting machine and internally evaluated using cross-validation. The external test cohort consisted of 225 patients with HCM from 3 medical centers. A total of 14 CMR imaging features (strain and late gadolinium enhancement [LGE]) and 23 clinical variables were evaluated and used to inform the ML model. MACEs included a composite of arrhythmic events, SCD, heart failure, and atrial fibrillation–related stroke. ResultsMACEs occurred in 191 (25%) patients over a median follow-up period of 109.0 months (Q1-Q3: 73.0-118.8 months). Our ML model achieved areas under the curve (AUCs) of 0.830 and 0.812 (internally and externally, respectively). The model outperformed the classic HCM Risk-SCD model, with significant improvement (P < 0.001) of 22.7% in the AUC. Using the cubic spline analysis, the study showed that the extent of LGE and the impairment of global radial strain (GRS) and global circumferential strain (GCS) were nonlinearly correlated with MACEs: an elevated risk of adverse cardiovascular events was observed when these parameters reached the high enough second tertiles (11.6% for LGE, 25.8% for GRS, −17.3% for GCS). ConclusionsML-empowered risk stratification using CMR and clinical features enabled accurate MACE prediction beyond the classic HCM Risk-SCD model. In addition, the nonlinear correlation between CMR features (LGE and left ventricular pressure gradient) and MACEs uncovered in this study provides valuable insights for the clinical assessment and management of HCM.

Cardiac magnetic resonance reveals biventricular impairment in Cushing’s syndrome: a multicentre case-control study

PurposeCushing’s syndrome (CS) is associated with severe cardiovascular (CV) morbidity and mortality. Cardiac magnetic resonance (CMR) is the non-invasive gold standard for assessing cardiac structure and function; however, few CMR studies explore cardiac remodeling in patients exposed to chronic glucocorticoid (GC) excess. We aimed to describe the CMR features directly attributable to previous GC exposure in patients with cured or treated endogenous CS.MethodsThis was a prospective, multicentre, case-control study enrolling consecutive patients with cured or treated CS and patients harboring non-functioning adrenal incidentalomas (NFAI), comparable in terms of sex, age, CV risk factors, and BMI. All patients were in stable condition and had a minimum 24-month follow-up.ResultsSixteen patients with CS and 15 NFAI were enrolled. Indexed left ventricle (LV) end-systolic volume and LV mass were higher in patients with CS (p = 0.027; p = 0.013); similarly, indexed right ventricle (RV) end-diastolic and end-systolic volumes were higher in patients with CS compared to NFAI (p = 0.035; p = 0.006). Morphological alterations also affected cardiac function, as LV and RV ejection fractions decreased in patients with CS (p = 0.056; p = 0.044). CMR features were independent of metabolic status or other CV risk factors, with fasting glucose significantly lower in CS remission than NFAI (p < 0.001) and no differences in lipid levels or blood pressure.ConclusionCS is associated with biventricular cardiac structural and functional impairment at CMR, likely attributable to chronic exposure to cortisol excess independently of known traditional risk factors.

Suspected cardiac masses evaluation with cardiac magnetic resonance : histological correlation and clinical outcomes

Abstract Background Cardiac masses are an heterogeneous group of very rare formations, representing a major diagnostic challenge given the difficulty in assessing their nature through imaging examinations. Cardiac Magnetic Resonance (CMR) is a noninvasive key diagnostic tool providing anatomical, functional, and tissue characteristic information. However, data validating this imaging approach are limited. Purpose analyze the clinical and CMR features of patients with benign and malignant tumors and thrombus; asses the diagnostic accuracy of CMR in comparison with the histologic examination; evaluate the prognostic rule of clinical and CMR features in predicting the primary endpoint of all cause mortality. Methods 92 Patients undergoing CMR for suspected cardiac mass between June 2004 and January 2022 were retrospectively evaluated. Patients with no mass 8 (9%) or pseudo-mass 11 (12%) were excluded. Based on CMR images, masses were divided into benign tumor, malignant tumor, and thrombus. Clinical, CMR and histological data were collected. Results 73 patients (mean age: 62±15; 51% female) with masses were finally enrolled, 27 (37%) with a diagnosis at CMR of benign tumor, 22 (30%) with malignant tumor, and 24 (33%) with thrombus. Several clinical and CMR variables were significantly associated with one type of mass rather than another. Among clinical variables the history of malignancy and smoking were seen in patients with malignant tumors (p&amp;lt;0,002) while dyspnea and chest pain were significantly found in patients with thrombi (p&amp;lt;0,016). Among CMR features high size, infiltration, pericardial repeats, pericardial effusion, signal inhomogeneity, First Pass Perfusion (FPP) and Late Gadolinium Enhancement (LGE) were associated with malignant masses (p=0.001), while reduced pre-contrast visualization, altered kinetics, low ejection fraction (EF) and long-TI were observed in thrombi (p=0.001). CMR was accurate in 91.2% (31/34) of patients in comparison with the histological examination. Accuracy for benign tumors was 91.3% (AUC=0.913), for malignant tumors 94% (AUC=0.940) and for thrombi 83% (AUC=0.833). Patients diagnosed at CMR with thrombus had similar mortality as those with benign tumor (p=0,678) while patients with malignant lesions had higher mortality (HR: 4.98 [95% CI: 1.11-22.2], p=0,035). Regardless of diagnosis at CMR, age, tumor history, mass size, signal inhomogeneity, presence of FPP, pericardial effusion, and pericardial repeats were found to predict long-term mortality (p&amp;lt;0.017). Conclusions Although CMR has high diagnostic accuracy, histologic examination remains the diagnostic gold standard in determining the type of cardiac mass. CMR is additionally useful in predicting the outcome and manage the clinical course of patients with suspected cardiac masses.

Arrhythmic risk stratification in patients with left ventricular ring-like scar

Abstract Background Myocardial fibrosis assessment with late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) has recently emerged as an independent predictor of major adverse events in patients with non-ischemic cardiomyopathy. Several studies have examined different locations and extension degrees of LGE, and the so called "ring-like pattern" has been related with an increased incidence of ventricular arrhythmias, in patients with dilated cardiomyopathy (DCM), but also in patients with preserved systolic function. Purpose To describe clinical, electrocardiographic, echocardiographic, CMR and genetic features of the left ventricular (LV) ring-like scar phenotype and to evaluate which characteristics may be associated with the risk of sudden cardiac death (SCD). Methods Patients diagnosed with LV ring-like scar were identified at 6 referral Centres. Diagnosis was based on: 1) ring-like LGE LV pattern, defined as at least 3 contiguous segments with subepicardial/midwall LGE in the same slice with or without fatty infiltration; or 2) pathology examination of explanted hearts/autoptic cases suffering from sudden cardiac death (SCD). Moreover, patients must have an additional inclusion criterion: a positive genetic test, or ≥1 patient in the same family with an ascertained cardiomyopathy. Major adverse arrhythmic cardiac events (MAACE), defined as a composite of SCD, aborted SCD, and sustained ventricular tachycardia (SVT), were the primary study endpoint. Results The final cohort comprised 129 patients (male 59.7%, median age at diagnosis 44 years). During a median follow-up of 3.4 years (IQR 1.2 – 64.), MAACE occurred in 31 patients (24%). Nearly 70% of the patients had a likely pathogenic/pathogenic mutation, mostly in desmoplakin (DSP) and filamin-C (FLNC) genes (65% and 19%, respectively). Sex, QRS width, and LGE in LV anterior wall and/or apex, were the only independent predictors of the outcome events (HR: 0.329, 95% CI: 0.119-0.916, P = 0.033; HR: 1.036, 95% CI 1.019-1.053, P &amp;lt; 0.001; HR 4.270, 95% CI 1.337-13.630, P = 0.014, respectively). A significant interaction between sex and LGE in anterior wall/apex was observed, being this regions associated with MAACE only in male patients (p for interaction = 0.033). Although related to the arrhythmic endpoint at the Kaplan-Meier survival curves, neither DCM echocardiographic phenotype, nor LV ejection fraction ≤35% remained statistically associated to MAACE at the multivariate analysis. Age, genetic mutations, right ventricular involvement, proband status, LV-LGE extension (number of segments) were not statistically related to the study endpoint. Conclusions In this selected cohort of patients with LV ring-like scar and either a genetic test or family history, malignant arrhythmic events were predicted by male sex, QRS width and LGE in anterior wall and/or apex.Graphical Abstract

Abstract 15036: Identification of Fabry Disease Cardiac Phenotype in Hypertrophic Cardiomyopathy With Cardiac Magnetic Resonance Imaging Technology

Introduction: Cardiac magnetic resonance(CMR), especially T1 mapping, has an important role in the diagnosis of Fabry disease, but the differential value in myocardial diseases with hypertrophic phenotype needs further study. More importantly, there has been no systematic study of the difference between different CMR techniques indistinguishing Fabry cardiomyopathy from hypertrophic cardiomyopathy (HCM). Hypothesis: Myomapping technology can be a parameter in distinguishing Fabry cardiomyopathy from HCM. Methods: We continuously included patients with clinically diagnosed hypertrophic cardiomyopathy, completed systematic magnetic resonance imaging, and used genetic testing as the diagnostic criteria. We reported the prevalence rate in the population of HCM, and deeply conducted comparative studies on the differences in magnetic resonance characteristics between Fabry disease and HCM. We also analyzed the diagnostic value of magnetic resonance imaging in distinguishing Fabry cardiomyopathy from HCM. Results: We continuously included patients diagnosed with hypertrophic cardiomyopathy at West China Hospital from 2012 to 2022 and completed systematic magnetic resonance imaging examinations. We reported the prevalence of Fabry cardiomyopathy in the population using genetic testing as the diagnostic criteria, and deeply conducted comparative studies on the differences in CMR features between Fabry disease and HCM. We also analyzed the diagnostic value of CMR in distinguishing Fabry cardiomyopathy from HCM. Conclusions: We found a prevalence of 13 (2.6%) cases of Fabry disease in the hypertrophic cardiomyopathy cohort (494 cases). Our further analysis found that there were no significant differences in the degree of hypertrophy, overall cardiac function and size of Fabry patients compared with patients with HCM, as well as strain analysis. NativeT1 was significantly reduced in Fabry disease, and segmental analysis found that the basal and middle ventricular septum and anterior wall were the most obvious. ECV differed significantly between the two groups. There was no difference in T2 between the two groups. ROC analysis showed that T1 had the most discriminating value

Cardiovascular magnetic resonance imaging in suspected cardiac masses: histological correlation and clinical outcomes

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac masses are an heterogeneous group of very rare formations, representing a major diagnostic challenge given the difficulty often encountered in assessing their nature through imaging examinations. Cardiac Magnetic Resonance (CMR) is a noninvasive key diagnostic tool providing anatomical, functional, and tissue characteristic information. However data validating this imaging approach are limited. Purpose 1) to analyze the clinical and CMR features of patients with benign and malignant tumors and thrombus; 2) to asses the diagnostic accuracy of CMR in comparison with the histologic examination;3) to evaluate the prognostic rule of clinical and CMR features in predicting the primary endpoint of all cause mortality. Methods 92 Patients undergoing CMR for suspected cardiac mass between June 2004 and January 2022 were retrospectively evaluated. Patients with no mass 8 (9%) or pseudomass 11 (12%) were excluded. Based on CMR images, masses were divided into benign tumor, malignant tumor, and thrombus. Clinical, CMR and histological data were collected. Results 73 patients (mean age: 62±15; 51% female) with masses were finally enrolled, 27 (37%) with a diagnosis at CMR of benign tumor, 22 (30%) with malignant tumor, and 24 (33%) with thrombus. Several clinical and CMR variables were significantly associated with one type of mass rather than another. Among clinical variables the history of malignancy and smoking were seen in patients with malignant tumors (p&amp;lt;0,002) while dyspnea and chest pain were significantly found in patients with thrombi (p&amp;lt;0,016). Among CMR features high size, infiltration, pericardial repeats, pericardial effusion, signal inhomogeneity, First Pass Perfusion (FPP) and Late Gadolinium Enhancement (LGE) were associated with malignant masses (p = 0.001), while reduced pre-contrast visualization, altered kinetics, low ejection fraction (EF) and long-TI were observed in thrombi (p = 0.001). CMR was accurate in 91.2% (31/34) of patients in comparison with the histological examination. Accuracy for benign tumors was 91.3% (AUC=0.913), for malignant tumors 94% (AUC=0.940) and for thrombi 83% (AUC=0.833). Patients diagnosed at CMR with thrombus had similar mortality as those with benign tumor (p = 0,678) while patients with malignant lesions had higher mortality (HR: 4.98 [95% CI: 1.11–22.2], p = 0,035). Regardless of diagnosis at CMR, age, tumor history, mass size, signal inhomogeneity, presence of FPP, pericardial effusion, and pericardial repeats were found to predict long-term mortality (p&amp;lt;0.017). Conclusions Although CMR has high diagnostic accuracy, histologic examination remains the diagnostic gold standard in determining the type of cardiac mass. In addition to playing a key role in the diagnostic process, CMR is also useful in predicting the clinical outcome of patients with cardiac masses.

Cardiac magnetic resonance features associated with the risk of cardiac arrest in patients with acute myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by the George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, Research Grant number NR. 164 / 26 / 10.01.2023. Background Cardiac arrest (CA) is the most severe complication of acute myocardial infarction (AMI). The role of different factors related to the site and severity of coronary occlusion in the pathogenesis of AMI-related cardiac arrest is still under investigation. The aim of the study was to investigate the association between (1) different cardiac magnetic resonance (CMR) features associated with the location and severity of the myocardial injury, and (2) the risk of CA accompanying an AMI. Methods In total, 54 patients AMI undergoing post-AMI CMR imaging with delayed gadolinium enhancement were enrolled in the study. The study lot was divided into 2 groups: group 1–8 patients who survived a CA in the acute phase of AMI and group 2–46 patients, matched for age and gender, with AMI but without CA. In all patients, infarct mass, the proportion of high transmural extent, and scar mass at different myocardial segments were calculated using the QMap software (Medis BV). Results Compared to patients without CA, those with CA had a significantly higher infarct mass (47.9 +/- 38 g versus 23.3 g, p = 0.03), infarct mass % (26.9 +/ 17.3% vs 15.1 +/- 8.6 %, p = 0.02), and a higher degree of transmurality (29.28 +/- 20.2 % vs 14.1 +/- 9.2 %, p = 0.01). Location of myocardial injury at the level of latero-apical, anterolateral, and bazal anterior segments seemed to be more frequently associated with the risk of CA in the acute phase of AMI: infarct mass 33.9 +/- 30.6 g in group 1 vs 13.6 +/- 17.3 g in group 2, p = 0.02 for the latero-apical segment, 26.5 +/- 29.0 g in group 1 vs 8.9 +/- 12.8 g in group 2, p = 0.02 for the anterolateral segment, and 20.1 +/- 21.5 g in group 1 vs 7.8 +/- 14.7 g in group 2, p = 0.02 for anterobazal segment. Conclusions Myocardial mas, high transmural extent at CMR imaging, and a large myocardial injury identified by CMR at the level of the anterior and lateral ventricular segments seems to be associated with an increased risk of CA in the acute phase of AMI.

Clinical and cardiac magnetic resonance profile of patients with COVID-19 vaccine-related myocarditis compared with other acute myocarditis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Spanish Cardiology Society, Cardiac Imaging Association. Grant for short extern fellowship in national centers. Background Reports have suggested an association between the development of myocarditis and mRNA vaccines against COVID-19 coronavirus disease. Cardiac magnetic resonance (CMR) findings in this setting have not been widely explored. Purpose The present study explores the clinical profile and CMR imaging findings in patients with a diagnosis of myocarditis during the period of 1 month after COVID-19 vaccination compared to non-related myocarditis during the same period. Methods All patients who underwent a CMR for suspected myocardial infarction with non-obstructive coronary arteries (MINOCA) during a period of 1 year from June 2021 to June 2022 were retrospectively evaluated. Myocarditis was defined by modified Lake Louise criteria (mLLC) and vaccine-related myocarditis was defined as a myocarditis episode in the period of 1 month after vaccination. Electronic medical records were analyzed to collect data on baseline clinical variables, CMR features and clinical events. Results A total of 118 consecutive patients undergoing a CMR for suspected MINOCA were included in the study of whom 48 (40,7%) fulfilled mLLC for myocarditis, of those, 15 cases (31,25%) were vaccine-related myocarditis. Both related and non-vaccine related myocarditis were more frequent among men and there were no differences in cardiovascular risk factors or baseline comorbidities between groups. CMR findings showed that vaccine-related myocarditis had similar LVEF and RVEF compared to other myocarditis and there were no differences in native T1, native T2 or extracellular volume (ECV). (Table 1). Edema in non-vaccine related myocarditis was more frequently observed in inferolateral mid and basal segments (segment 11) whilst in vaccine-related myocarditis edema was more frequently observed in inferoseptal mid segment (segment 9). There were no differences in the localization of the late gadolinium enhancement (LGE). (Table 2.) CMR follow-up was performed in 30 patients between 6 to 8 months after admission, showing LGE persistence without edema in 70% of non-vaccine related patients and 77,8% of vaccine-related patients. There were only 2 myocarditis recurrences. During the clinical follow up there were no deaths or ventricular arrhythmias, there were 3 hospital readmissions, 2 of them for a new myocarditis episode and 1 due to an unrelated myocardial infarction. Conclusions Vaccine-related myocarditis represented a significant proportion of new myocarditis diagnosis from June 2021 and June 2022. There were no differences in baseline characteristics, index CMR and CMR follow-up features between both subtypes. Clinical follow up of vaccine-related myocarditis showed no important events.

Late gadolinium enhancement persistence in early cardiac magnetic resonance follow-up after acute myocarditis

Abstract Funding Acknowledgements Type of funding sources: None. Background Multiparametric cardiac magnetic resonance (CMR) evaluation with modified Lake Louise criteria (mLLC) is the gold standard non-invasive test for the diagnosis of acute myocarditis. Although CMR in the follow-up may inform of edema resolution and myocardial fibrosis there is a lack of consensus on the optimal time interval to perform it and the clinical and prognostic differences between patients with complete resolution and those who present late gadolinium enhancement (LGE) persistence. Purpose To describe the clinical profile, CMR findings, early CMR follow-up and clinical events in patients with acute myocarditis focusing on the differences between patients who present complete LGE resolution versus patients with LGE persistence. Methods All patients who underwent a CMR for a suspected myocarditis during a period of 1 year from June 2021 to June 2022 were retrospectively evaluated. Those with a confirmed myocarditis by mLLC and a follow-up CMR were included. Electronic medical records were analyzed to collect data on baseline clinical variables, CMR features and follow-up events. Follow-up CMR was performed on follow-up based on clinician’s criteria. Results A total of 27 patients fulfilled mLLC for myocarditis during the period of study and had a follow-up CMR. The mean time to first CMR control was 186 +/- 95 days (6,2 months). Of those 23 (85.2%) presented persistent LGE enhancement and 4 of them presented a complete resolution of LGE. There were no statistically significant differences between groups although patients with complete LGE resolution tend to be younger. There were no differences between groups in terms of LVEF and RVEF. Patients with persistent LGE in the follow-up tend to have higher edema and LGE extension during the acute myocarditis episode, being the LGE difference statistically significant. In the follow up CMR almost all patients presented edema resolution and although the majority of patients (85.2%) presented LGE persistence they presented a trend to a decrease of affected segments (4.4 to 3.1 after mean time of 6 months). There were no differences in clinical events between groups in terms of death, admissions, ventricular arrhythmias and new episodes of myocarditis, patients with persistent LGE tend to have more visits for unresolved chest pain. Conclusions The majority of patients with a confirmed acute myocarditis had edema resolution and LGE persistence after 6 months. There were no differences in clinical events during follow-up. Follow up CMR before 6 months can prove resolving edema but LGE persistance is common. Further studies are needed to define the optimal interval to perform CMR after the index event.

Myocardial edema at CMR imaging end evolution of ventricular function following COVID-19 myocarditis - insights from the CARDIOCOV study

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): The CARDIOCOV project - Prototype for personalized assessment of cardiovascular risk and post-Covid myocarditis based on artificial intelligence, advanced medical imaging and cloud computing - financed by UEFISCDI PN-III-P2-2.1-PTE-2021-0450 (Contract Number 108PTE/2022). Background Myocarditis following SARS-COV-2 infection has recently become a subject of concern, being detected in a significant number of post-COVID-19 patients who undergo cardiac magnetic resonance(CMR) examination. While the role of CMR in detecting presence of viral myocarditis has been well established, the CMR features associated with significant alteration of ventricular function in post-COVID patients are not clearly identified yet. Purpose The aim of the study was to investigate the role of myocardial edema (ME) at CMR for predicting the evolution of ventricular function in patients with COVID myocarditis. Methods In total, 55 patients with CMR signs of viral myocarditis following COVID-19 infection (52.72% males, mean age 36.85+/-16.29) were enrolled in the study. The delayed gadolinium enhancement phase-sensitive inversion recovery sequences were used for characterization of the myocardial tissue, and inversion recovery images showing high signal intensity were considered suggestive of edematous changes. Patients were divided into 2 study groups, according to the presence of myocardial edema at the moment of CMR evaluation: group 1 (n=18, 32.72%) - patients without ME, and group 2 (n=37, 67.27%)-patients with ME identified by CMR. In all patients, end-distolic and end-systolic volume indexes (EDVI and ESVI), ejection fraction (EF) and stroke volume (SV) were calculated. Results Compared to patients without ME, those with ME present at CMR were older n (42.9+/-14.8 vs. 36.7+/-16.6, p = 0.145) and more frequently males(59.4% vs. 38.8%). At the same time, EF was significantly lower in patients with ME(50.9+/-14.5% in group 2 vs. 58.4+/-10.2% in group 1, p = 0.03). Patients from group 2 also exhibited a more pronounced dilatation of ventricular cavities, as reflected by a significant increase of ventricular volumes and especially of the ESVI(109.8+/-125.9 versus 80.1+/-14.2, p = 0.5 for EDVI, and 65.2+/-109.1 vs. 30.0+/-11.4, p = 0.02 for ESVI). Compared to the group without ME, those with ME presented a significantly lower stroke volume index: 44.2+/-17.3 in group 1 vs. 47.7+/-7.5, p = 0.03 in group 2. Conclusions In patients with COVID-19 myocarditis, presence of ME at CMR imaging is associated with a worse evolution of the left ventricular function, as reflected by increased ventricular dilatation and decreased cardiac output in the post-COVID period.

Novel insights into cardiovascular ageing in the general population using machine learning

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation (RG/19/6/34387, RE/18/4/34215). Background Population ageing is a global trend and places an increased burden on healthcare resources, predominantly through cardiovascular morbidity and mortality. Ageing can be detected in the cardiovascular system as a decline in structure and function through cardiac magnetic resonance (CMR) imaging. This decline occurs at both organ and cellular levels, modulated by genetic, oxidative, inflammatory and metabolic stresses. Effect sizes and mechanisms of cardiovascular ageing are currently unknown; moreover, a robust biomarker is lacking. Purpose To develop a cardiovascular ageing model using CMR features to quantify an individual’s deviation ("age-delta") from healthy ageing and explore potential mechanisms contributing to the process. Methods We used data from the UK Biobank (UKB), a population-based cohort study of over 500,000 participants aged 40–69 recruited between 2006–2010. We studied 39,559 participants that had a CMR scan and used a machine learning model to estimate a "cardiovascular age" in 5065 healthy individuals from imaging traits including cardiac volumes, diastolic function, aortic distensibility and T1 mapping of fibrosis (Figure 1a). We applied this trained healthy ageing model to predict cardiovascular age in 34,147 new individuals (Figure 1b) and computed their age-deltas, which we used in a linear regression model to calculate the effect-sizes of selected diseases and lifestyle factors. We next performed a genome wide association study on 29,506 subjects to identify significant single nucleotide polymorphism (SNP) associations and computed a polygenic risk score in 373,948 independent genotyped participants of UKB to further explore phenotypic associations in a phenome wide association study. Results Hypertension (+1.58 years), diabetes (+0.74 years), smoking (+0.031 years/pack year) and alcohol (+0.015 years/gram per day) were significantly associated with adverse cardiovascular ageing (Figure 2a). Heart rate, blood pressure, inflammatory biomarkers and alkaline phosphatase were also significantly correlated with accelerated cardiovascular ageing, whereas telomere length, greater lung function, fat-free mass and basal metabolic rate were significantly correlated with attenuated ageing. GWAS revealed variants that contribute to myocardial contractility (Titin), arterial function (Elastin), inflammatory states (PLCE1, TREM2) and calcium signalling (MICU3) (Figure 2b). Conclusion Our study introduces a general population-derived CMR-based biomarker for cardiovascular ageing, which may in future be used to summarise an individual’s trajectory of ageing. The associations established with risk factors and physical measures could enable personalised cardioprotective interventions, complemented by novel therapies targeting mechanistic pathways discovered by our genetic associations.

Cardiovascular magnetic resonance findings in Danon disease: a case series of a family.

Cardiac involvement constitutes the primary cause of mortality in patients with Danon disease (DD). This study aimed to explore the cardiac magnetic resonance (CMR) features and progressions of DD cardiomyopathies in a family with long-term follow-up. Seven patients (five females and two males), belonging to the same family and afflicted with DD, were enrolled in this study between 2017 and 2022. The cardiac structure, function, strain, tissue characteristics on CMR and their evolutions during follow-up were analyzed. Three young female patients (3/7, 42.86%) exhibited normal cardiac morphology. Four patients (4/7, 57.14%) displayed left ventricle hypertrophy (LVH), and mostly with septal thickening (3/4, 75%). A single male case (1/7, 14.3%) showed decreased LV ejection fraction (LVEF). Nonetheless, the global LV strain of the four adult patients decreased in different degree. The global strain of adolescent male patients was decreased compared to the age-appropriate female patients. Five patients (5/7, 71.43%) exhibited late gadolinium enhancement (LGE), with proportion ranging from 31.6% to 59.7% (median value 42.7%). The most common LGE location was the LV free wall (5/5, 100%), followed by right ventricle insertion points (4/5, 80%) and intraventricular septum (2/5, 40%). Segmental radial strain (rs = -0.586), circumferential strain (r = 0.589), and longitudinal strain (r = 0.514) were all moderately correlated with the LGE proportions of corresponding segments (P < 0.001). T2 hyperintense and perfusion defect foci were identified, overlapping with the LGE areas. During follow-up, both the young male patients exhibited notable deterioration of their cardiac symptoms and CMR. The LVEF and strain decreased, and the extent of LGE increased year by year. One patient underwent T1 mapping examination. The native T1 value was sensitively elevated even in regions without LGE. Left ventricular hypertrophy, LGE with sparing or relatively less involved IVS, and LV dysfunction are prominent CMR features of Danon cardiomyopathy. Strain and T1 mapping may have advantages in detecting early-stage dysfunction and myocardial abnormalities in DD patients, respectively. Multi-parametric CMR can serve as an optimal instrument for detecting DD cardiomyopathies.

Serum amyloidosis: a cardiac amyloidosis.

A 75-year old male with a history of membranoproliferative glomerulonephritis requiring kidney transplant, carpal tunnel, and peripheral neuropathy presented with new heart failure. An echocardiogram revealed moderate, concentric left ventricular hypertrophy (LVH) despite normal electrocardiographic voltage. To evaluate for the aetiology of unexplained LVH, a cardiac magnetic resonance (CMR) was performed which showed increased wall thickness with markedly increased T1 relaxation time and extensive, near-transmural late gadolinium enhancement throughout the myocardium (Panels A–C, green arrows), findings highly concerning for cardiac amyloidosis (CA). Despite this, a 21.5 mCi Tc-99 m pyrophosphate (Tc-PyP) scan and comprehensive serum (Panels D and E) and urine light chain analysis showed no evidence of transthyretin or immunoglobulin light chain CA, respectively. Despite these negative findings, the patient was referred for endomyocardial biopsy due to high clinical concern for CA. His biopsy revealed diffuse myocardial amyloid deposition (Panels E and F) which was ultimately identified as serum amyloid A (AA) protein on mass spectrometry. AA-CA is a rare form of cardiac amyloidosis caused by deposition of SAA protein—an acute phase reactant—in the myocardium. This disorder is most commonly observed in patients with longstanding chronic inflammatory conditions and is frequently missed by conventional light chain and Tc-PyP analysis. Renal dysfunction is a key feature of AA-CA and is present in a most cases. This case highlights the importance of having a low threshold to pursue further testing including invasive tissue biopsy when typical CA CMR features are present even in the absence of confirmatory non-invasive testing.

Role of cardiac magnetic resonance in the differential diagnosis between arrhythmogenic cardiomyopathy with left ventricular involvement and previous infectious myocarditis.

AimsArrhythmogenic cardiomyopathy with left ventricular involvement (ACM-LV), particularly in case of isolated left ventricular involvement (i.e. left dominant arrhythmogenic cardiomyopathy, LDAC) and previous infectious myocarditis (pIM) may have overlapping clinical and cardiac magnetic resonance (CMR) features. To date, there are no validated CMR criteria for the differential diagnosis between these conditions. The present study aimed to identify CMR characteristics to distinguish ACM-LV from pIM. Methods and resultsThis observational, retrospective, single-centre study included 30 pIM patients and 30 ACM-LV patients. In ACM-LV patients CMR was performed at diagnosis; in patients with pIM, CMR was performed six months after acute infection. CMR analysis included quantitative assessment of left ventricle (LV) volumes, systolic function and wall thicknesses, qualitative and quantitative assessment of late gadolinium enhancement (LGE) sequences. Compared with pIM, ACM-LV patients showed slightly larger LV volumes, more frequent regional wall motion anomalies and reduced wall thicknesses. ACM-LV patients had higher amounts of LV LGE and extension. Notably, the LDAC subgroup had the highest amount of LV LGE. LV LGE amount > 15 g and a LV LGE percentage > 30% of LV mass discriminated ACM-LV from pIM with a 100% specificity. LGE segmental distribution was superimposable among the groups, except for septal segments that were more frequently involved in ACM-LV and LDAC patients. ConclusionsA great extension of LV LGE (a cut-off of LGE >15 g and a percentage above 30% of LV LGE in relation to total myocardial mass) discriminates ACM-LV from pIM with extremely high specificity.

1016 CARDIAC MAGNETIC RESONANCE IMAGING IN DIFFERENTIAL DIAGNOSIS OF CARDIAC MASSES

Abstract Background Differential diagnosis of cardiac masses represents a challenging issue with important implications for therapeutic management and patient's prognosis. Cardiac Magnetic Resonance (CMR) is a non-invasive imaging technique used to characterize morphologic and functional features of masses. Integration of these information can lead to an accurate diagnosis. Purpose To evaluate the diagnostic role of CMR in defining the nature of cardiac masses. Methods One hundred-fourteen patients with cardiac masses evaluated with CMR were enrolled. All masses had histological certainty. CMR sequences allowed a qualitative morphologic description as well as tissue characterization. Evaluation of masses morphology included localization, size and borders assessment, detection of potential multiple lesions and pericardial effusion. Tissue characterization resulted from an estimation of contrast enhancement - early gadolinium enhancement (EGE) and late gadolinium enhancement (LGE) sequences - and tissue homogeneity in T1 and T2 weighted acquisitions. The descriptive analysis was carried out by comparing benign vs malignant lesions as well as dividing patients into 4 subgroups: primitive benign tumours, primitive malignant tumours, metastatic tumours and pseudotumours. Results The descriptive analysis of morphologic features showed that diameter &amp;gt; 50 mm, invasion of surrounding planes, irregular margins and presence of pericardial effusion were able to predict malignancy (p &amp;lt; 0.001). As for tissue characteristics, heterogeneous signal intensity - independently from T1 and T2 weighted acquisitions - and EGE were more common in malignant lesions (p &amp;lt;0.001). When analysing the four subgroups, CMR features did not discriminate between primitive malignant masses and metastasis. Conversely, hyperintensity signal in T2 w-TSE, EGE and heterogeneity after gadolinium enhancement were more common in benign primitive lesions compared to pseudotumours. Furthermore, using classification and regression tree (CART) analysis, we developed an algorithm to differentiate masses: invasion of surrounding planes was a common characteristic of malignancy and identifies itself malignant tumours. In the absence of invasive features, gadolinium enhancement was evaluated: the lack of contrast uptake was able to increase the probability of a pseudotumour. Last step of decision algorithm included ejection fraction assessment to discriminate between benign tumours: a reduced ejection fraction increased the probability of pseudotumour diagnosis and reduced the probability of primary benign tumour diagnosis. Conclusions Cardiac magnetic resonance is a very powerful diagnostic tool for differential diagnosis of cardiac masses as it correctly addresses malignancy. Furthermore, an accurate evaluation of the several CMR features may discriminate primary benign masses and pseudotumours.

458 CARDIOVASCULAR MAGNETIC RESONANCE IMAGING IN SUSPECTED CARDIAC MASSES: HISTOLOGICAL CORRELATION AND CLINICAL OUTCOMES

Abstract Background Cardiac masses represent a major diagnostic challenge given the difficulty in assessing their nature through imaging examinations. Cardiac Magnetic Resonance (CMR) is a noninvasive key diagnostic tool that can provide important anatomical, functional, and tissue characteristic information. Objectives of the study analyze the clinical and CMR features of patients with benign and malignant tumors and thrombus; asses the accuracy of CMR in comparison with the histologic examination; evaluate the prognostic rule of clinical and CMR features in predicting the primary endpoint of all cause mortality. Methods 92 Patients undergoing CMR for suspected cardiac masses between June 2004 and January 2022 were retrospectively evaluated. Patients with no mass 8 (9%) or pseudomass 11 (12%) were excluded. Clinical, CMR and histological data were collected. Results 73 patients with masses were finally enrolled, 27 (37%) with a diagnosis at CMR of benign tumor, 22 (30%) with malignant tumor, and 24 (33%) with thrombus. Among clinical variables the history of malignancy and smoking were seen in patients with malignant tumors (p&amp;gt;0,02). Among CMR features high size, infiltration, pericardial repeats, pericardial effusion, signal inhomogeneity, First Pass Perfusion and Late Gadolinium Enhancement were associated with malignant masses (p&amp;lt;0.05), while reduced pre-contrast visualization, altered kinetics, low ejection fraction and long-TI were observed in thrombi (p&amp;lt;0.05). CMR was accurate in 91.2% (31/34) of patients in comparison with the histological examination. Accuracy for benign tumors was 91.3% (AUC=0.913), for malignant tumors 94% (AUC=0.940) and for thrombi 83% (AUC=0.833). Patients with thrombus at CMR had similar mortality as those with benign tumor while patients with malignant lesions had higher mortality (HR: 4.98 [95% CI: 1.11-22.2]). Regardless of diagnosis at CMR, age, tumor history, mass size, signal inhomogeneity, presence of FPP, pericardial effusion, and pericardial repeats were found to predict long-term mortality (p&amp;lt;0.05). Conclusions although CMR has high diagnostic accuracy, histologic examination remains the diagnostic gold standard in determining the type of cardiac mass. In addition to playing a key role in the diagnostic process, CMR is useful in predicting the outcome of patients with cardiac masses.