Sudden cardiac death in younger adults: a comparative analysis of coronary and non-coronary causes
TL;DR
Non-coronary and idiopathic etiologies represent a substantial proportion of SCD in younger adults and support standardized post-arrest evaluation, including multimodality imaging, inherited arrhythmia assessment, genetic testing, family screening, and longitudinal expert review.
Abstract
Aims We aimed to characterize etiologies and outcomes of patients aged 16–65 years after resuscitated sudden cardiac death (SCD), with particular emphasis on non-coronary and idiopathic cases. Methods This retrospective single-center study screened admissions from 2010 to 2021 using ICD-10 codes followed by manual chart review. Patients were classified as having coronary, non-coronary, or unclassified etiology. Follow-up of hospital survivors included chart review, structured interviews, and device interrogation where available. Results Of 232 patients meeting the initial inclusion criteria, 187 had sufficient diagnostic information for etiological classification: 139 had coronary and 48 non-coronary causes, while 45 remained unclassified because early death or incomplete diagnostic information precluded reliable assignment. In the classified cohort, 136 patients (72.7%) experienced out-of-hospital cardiac arrest. Coronary artery disease accounted for 94.2% of coronary cases. In the non-coronary group, 54.2% remained idiopathic; identified causes included cardiomyopathies (29.2%), myocarditis (8.3%), and channelopathies (6.3%). CPR duration <10 min was associated with lower in-hospital mortality, whereas duration ≥60 min was associated with higher mortality. Of 118 hospital survivors, structured follow-up was completed in 74 patients (median 77 months). ICD implantation was more frequent in non-coronary than coronary cases (68.8% vs. 18.7%). Among 47 patients with device follow-up, appropriate ICD shocks occurred in 23.1% and 19.0%, respectively. Conclusions Non-coronary and idiopathic etiologies represent a substantial proportion of SCD in younger adults. The high proportion of unexplained cases supports standardized post-arrest evaluation, including multimodality imaging, inherited arrhythmia assessment, genetic testing, family screening, and longitudinal expert review. Recurrent ventricular arrhythmias in both groups support ICD-based secondary prevention in selected survivors.