Long-term outcomes of catheter ablation for sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy

Background Hypertrophic cardiomyopathy (HCM) is a genetic myocardial disease associated with ventricular arrhythmia and sudden cardiac death (SCD). Although implantable cardioverter-defibrillators (ICDs) have reduced the incidence of SCD, many patients with HCM continue to experience frequent shocks due to monomorphic ventricular tachycardia (VT), particularly in the presence of apical aneurysms or end-stage (dilated-phase) remodeling. The available data on catheter ablation for VT in HCM remain limited, and prior studies have mainly addressed feasibility and safety rather than long-term efficacy or characteristics of arrhythmogenic substrates. Objective This study aimed to evaluate the clinical characteristics, electrophysiological findings, and long-term outcomes of catheter ablation for sustained VT in patients with hypertrophic cardiomyopathy. Methods This retrospective single-center study included 16 patients with HCM who underwent catheter ablation for sustained VT at the Electrophysiology Unit, Department of Cardiology of our University between January 2017 and December 2024. Baseline clinical, echocardiographic, and procedural data were obtained from institutional electronic medical records Results The mean age of the study population was 50.6 ± 16.5 years, and 75% were male. The most common comorbidity was hypertension, which was present in 43.8% of the patients. No patient had undergone surgical septal myectomy, whereas transcoronary septal ablation had been performed in 12.5%. Left ventricular outflow tract obstruction was present in 12.5% of patients. The mean left ventricular ejection fraction was 51.8 ± 12.1%, and 81% of patients had an implanted cardioverter-defibrillator. Apical HCM morphology was observed in 43.8% of cases, while 18.8% had a history of VT storm. The mean total procedure time was 199.8 ± 56.4 minutes, with an average ablation time of 26.0 ± 14.6 minutes. Combined endocardial and epicardial mapping/ablation was performed in 9 patients (56%), while 7 (44%) underwent endocardial-only ablation. Low-voltage scar areas were identified in 50% of the cohort, most frequently involving apical and septal regions. The mean follow-up duration was 49.6 ± 32.9 months (median 53.4, IQR 18.3–84.6). During this period, 7 of 16 patients (43.8%) experienced VT recurrence. Kaplan–Meier analysis demonstrated a median VT-free survival time of 73.5 months (95% CI 33.9–113.0). No major procedural complications were observed. Conclusion Catheter ablation for sustained VT in patients with HCM appears to be a feasible and reasonably safe approach that may provide acceptable long-term arrhythmia control. These findings suggest that catheter ablation could be considered as a therapeutic option in selected HCM patients with recurrent VT.