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Abstract Background The real-world prevalence of sudden cardiac death (SCD)–related gene mutations and their relationship with implantable cardioverter-defibrillator (ICD) implantation in dilated cardiomyopathy (DCM) has not been clearly investigated. Methods This study included patients with sporadic DCM with persistent left ventricular ejection fraction (LVEF) ≤ 35% even after 3 months of guideline-directed medical treatment or those with an ICD for secondary prevention and LVEF < 50%. Genetic tests targeting 444 pan-cardiomyopathy genes (including 36 core DCM genes) were performed, along with the collection of clinical and electrophysiological information. Results A total of 105 patients were enrolled (median age, 65.0 57.5–75.0 years), and 33 (31%) were women. The average LVEF was 27.4 ± 5.9%, and 46 patients (44%) had ICD or cardiac resynchronization therapy with ICD (34 for primary prevention and 12 for secondary prevention purpose) at the time of enrollment. Fourteen patients (13%) had pathogenic (P) or likely pathogenic (LP) variants (comprising 6 TTN , 4 DSP , 2 TNNT2 , 1 RBM20, 1 DSG and 1 MYBPC3 , one patients had both DSP and RBM20 ), and 59 patients (56%) had P/LP/variant of uncertain significance (VUS) in the 36 core DCM genes. Twenty-eight patients (27%) harbored SCD-related gene variants (14 DSP , 11 FLNC , 9 RBM20 and 2 TMEM43 ). The prevalence of SCD gene variants tended to be higher in the secondary prevention and non-ICD groups (33.3% for secondary purposes, 11.8% for primary purposes, and 33.8% for non-ICD; p = 0.058). Conclusions In patients with advanced heart failure and DCM, P/LP-validated DCM variants were not common in sporadic cases. However, when extended to VUS, approximately half of the patients had core DCM-related variants. The prevalence of SCD variants was not lower in the non-ICD group, thus suggesting a potential risk of fatal arrhythmia. (Trial registration: CRIS KCT0004913)
Kim et al. (Sat,) studied this question.