Impact of Phenotype on Recurrence of VT Post‐Ablation in Patients With Nonischemic Cardiomyopathy

BACKGROUND: Ventricular tachycardia (VT) ablation outcomes in nonischemic cardiomyopathy (NICM) may differ by disease phenotype, but prior studies have pooled NICM as a single entity. We performed a phenotype-stratified meta-analysis of VT ablation outcomes across six major NICM subtypes. METHODS: We systematically searched PubMed, Embase, and the Cochrane Library through January 2026. Studies were stratified by phenotype: lamin A/C (LMNA), cardiac sarcoidosis, dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), myocarditis, and arrhythmogenic right ventricular cardiomyopathy (ARVC). The primary outcome was VT recurrence. Proportions were pooled using restricted maximum likelihood estimation on the logit scale. Phenotype differences were tested via mixed-effects meta-regression. RESULTS: Eighteen studies (1699 patients) met inclusion criteria after rigorous center-level overlap resolution. VT recurrence differed significantly across phenotypes (F [5,12] = 3.78, p = 0.027). LMNA had the highest recurrence (82.6%; 95% CI 51.6%-95.5%; k = 5), followed by sarcoidosis (57.1%; 32.2%-78.8%; k = 2), DCM (42.7%; 24.1%-63.6%; k = 4), HCM (36.2%; 23.8%-50.7%; k = 2), myocarditis (34.5%; 27.3%-42.5%; k = 2), and ARVC (33.8%; 16.0%-57.9%; k = 3). Phenotype explained 44.7% of between-study heterogeneity. CONCLUSIONS: VT ablation outcomes in NICM varied by the underlying disease phenotype, with recurrence rates ranging from 82.6% in LMNA cardiomyopathy to 33.8% in ARVC. These hypothesis-generating findings argue against treating NICM as a unified category and provide a foundation for phenotype-specific procedural counseling and clinical trial stratification that warrants validation in prospective registries.