Timing of Catheter Ablation for Ventricular Tachycardia in Ischemic Cardiomyopathy: Evidence, Mechanisms, and the Emerging Role of Timely ICD-Guided Intervention.

BACKGROUND: The optimal timing of catheter ablation for ventricular tachycardia (VT) in ischemic cardiomyopathy remains uncertain, with strategies ranging from prophylactic intervention to delayed treatment after recurrent arrhythmia. Increasing evidence suggests that the timing of ablation may critically influence both arrhythmic and clinical outcomes.

OBJECTIVE: To synthesize contemporary evidence on VT ablation timing and to examine the mechanistic and clinical rationale supporting a timing-oriented therapeutic framework.

METHODS: We performed a structured narrative review of randomized trials, observational studies, and mechanistic investigations evaluating different ablation strategies, including prophylactic, early, and ICD-guided approaches. Particular emphasis was placed on integrating clinical outcomes with experimental and imaging data on post-infarct substrate evolution.

RESULTS: Prophylactic ablation reduces arrhythmic burden but has not demonstrated consistent survival benefit. Early ablation strategies improve procedural outcomes but are limited by heterogeneous definitions and inconsistent prognostic impact. By contrast, a timely ICD-guided approach-based on the first device-verified arrhythmic event-has demonstrated consistent reductions in VT recurrence and ICD therapies, with emerging but heterogeneous signals of survival benefit in randomized trials. Mechanistic evidence supports this paradigm, showing that the post-infarct scar is dynamic and continues to remodel over time, with increasing arrhythmogenic complexity. The first ICD-treated arrhythmia may therefore represent a biologically meaningful inflection point for intervention. Imaging and computational tools can refine patient selection and procedural planning after this trigger, while emerging ablation technologies may expand treatment options but do not modify timing strategies.

CONCLUSIONS: A timing-oriented approach to VT ablation, anchored to clinically meaningful ICD-verified arrhythmic events, provides the most coherent integration of mechanistic insight and clinical evidence. This strategy may also have relevant implications for healthcare utilization, although formal cost-effectiveness data remain limited. Future work should focus on refining patient selection within this therapeutic window and evaluating how evolving technologies can be integrated without compromising the central importance of timing.