Work

Myocardial fibrosis predicts sudden cardiac death in patients with hypertrophic cardiomyopathy after cardiac electronic device implantation: Insights from cardiovascular magnetic resonance imaging

Year: 2025

Type: article

Abstract: Background Hypertrophic cardiomyopathy (HCM) patients face increased risk of sudden cardiac death (SCD), and myocardial fibrosis is predictive of ventricular arrhythmias.Objective This study aims to determine whether the location, pattern, and quantification of myocardial fibrosis predicts SCD in HCM patients after cardiac implantable electronic device (CIED) implantation. MethodsThis study included HCM patients completed cardiovascular magnetic resonance (CMR) and received CIED between June 2017 and January 2023.The primary outcome was SCD or SCD-equivalent events (composite of SCD, resuscitated cardiac arrest, sustained ventricular tachycardia or ventricular fibrillation, or appropriate ICD therapy). ResultsEighty-eight patients were included (age 52.3 ± 15.3 years; 67.0% male).Over a median follow-up period of 38.1 months, 27 (30.6%)SCD events were recorded.Fibrosis in inferior wall, transmural pattern, total fibrosis (TF), and gray zone fibrosis (GZF) were all significantly associated with SCD risk.Stepwise regression analyses identified the transmural fibrosis pattern (HR=3.15,95% CI 1.22-8.14,P=0.018), and increased GZF6SD (HR=3.49,95% CI 1.31-9.25,P=0.012) as independent predictors of SCD risk.Incorporating both transmural fibrosis and GZF6SD≥21.00%into the HCM 5-year SCD risk model significantly improved J o u r n a l P r e -p r o o f predictive value from 0.69 (95% CI 0.54-0.84) to 0.76 (95% CI 0.62-0.89;P for 63 comparison=0.002).The net reclassification improvement was 0.35 (95% CI 0.13-64 0.57, P=0.002), and the integrated discrimination improvement was 0.04 (95% CI 65 0.02-0.06,P<0.001).66 Conclusion Transmural fibrosis, and elevated GZF6SD are predictors of SCD in HCM 67 patients after CIED implantation and provide additional value to existing risk scoring 68 system.

Source: Heart Rhythm O2

DOI: 10.1016/j.hroo.2025.10.012