Non-ischemic cardiomyopathy (NICM) is one of the most important entities for arrhythmias and sudden cardiac death (SCD). Previous studies suggest a lower benefit of implantable cardioverter–defibrillator (ICD) therapy in patients with NICM as compared to ischemic cardiomyopathy (ICM). Nevertheless, current guidelines do not differentiate between the two subgroups in recommending ICD implantation. Hence, risk stratification is required to determine the subgroup of patients with NICM who will likely benefit from ICD therapy. Various predictors have been proposed, among others genetic mutations, left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic volume (LVEDD), and T-wave alternans (TWA). In addition to these parameters, cardiovascular magnetic resonance imaging (CMR) has the potential to further improve risk stratification. CMR allows the comprehensive analysis of cardiac function and myocardial tissue composition. A range of CMR parameters have been associated with SCD. Applicable examples include late gadolinium enhancement (LGE), T1 relaxation times, and myocardial strain. This review evaluates the epidemiological aspects of SCD in NICM, the role of CMR for risk stratification, and resulting indications for ICD implantation.

We report a family with heterozygous deletion of exons 3–6 of the LMNA gene. The main presentation of affected family members was characterized by ventricular and supraventricular arrhythmias, atrioventricular (AV) block and sudden cardiac death (SCD) but also by severe dilative cardiomyopathy (DCM). We report on two siblings, a 36-year-old female and her 40-year-old brother, who suffer from heart failure with mildly reduced ejection fraction, AV conduction delays and premature ventricular complexes. Their 65-year-old mother underwent heart transplantation at the age of 55 due to advanced heart failure. Originally, the LMNA mutation was detected in one of the uncles. This index patient and three of his brothers died of SCD as well as their father and aunt. The two siblings were treated with implanted defibrillators in our specialized tertiary heart failure center. This case report places this specific genetic variant in the context of LMNA-associated familial DCM.

Background: While primary mitral valve regurgitation (PMR) results from structural abnormalities of the mitral valve leaflets, secondary mitral valve regurgitation (SMR) arises from either mitral annular dilatation (atrial type, aSMR) or left ventricle remodelling (ventricular type, vSMR) in the absence of intrinsic leaflet disease. Although SMR is considered the most common cause of clinically relevant mitral regurgitation (MR), population-based data on its prevalence, subtype distribution, and clinical profiles are lacking. We aimed to determine the prevalence of PMR and SMR and to characterize PMR, aSMR, and vSMR in the general population. Methods: We analyzed the first 10,000 participants of the population-based Hamburg City Health Study enrolled 2016–2019; 8543 echocardiographic examinations were available. Mitral valve morphology and function were independently assessed by two investigators. PMR was defined by the presence of intrinsic leaflet pathology, whereas SMR was classified as ventricular when left ventricular ejection fraction was less than 50% or less than 55% in the presence of geometric distortion (tenting area ≥ 150 mm ² or coaptation depth ≥ 10 mm) and cases with left ventricular ejection fraction equal to or above 50% were classified as aSMR. Results: A total of 216 participants had moderate or severe MR (2.53% of the total cohort, 95% confidence interval (CI): 2.20%–2.89%, see Fig. 3). Of these, 148 were classified as SMR (68.5%, 95% CI: 61.8%–74.7%), the remaining were mainly of primary etiology (31.5%, 95% CI: 25.3%–38.2%). Among SMR cases, aSMR was predominant (84.5%, 95% CI: 77.5%–89.9%), whereas vSMR accounted for 15.5% (95% CI: 10.1%–22.4%). Compared with aSMR, individuals with vSMR were older, more symptomatic, and more frequently had atrial fibrillation and hypertension. Echocardiographic parameters indicated more advanced cardiac remodelling and dysfunction in vSMR. Compared with SMR, participants with PMR had greater MR severity, while age and the proportion of women were numerically higher without reaching statistical significance. During a median follow-up of 4.56 years, 10 participants had died, with all-cause mortality being significantly higher among participants with PMR than among those with aSMR. Conclusion: In this population-based cohort, SMR accounted for two-thirds of relevant MR, with aSMR being the predominant subtype. MR severity was higher in PMR as compared to SMR. Distinct echocardiographic and clinical profiles suggest more advanced disease in vSMR. Multivariate analysis revealed that atrial fibrillation was significantly more present in the vSMR cohort. These findings highlight the need for refined SMR subclassification and longitudinal studies to define prognostic implications and clinically meaningful definitions. All-cause mortality was highest in participants with PMR than in those with aSMR.