Impact of timing of recurrence following catheter ablation of scar-related ventricular tachycardia on subsequent mortality

Background: Catheter ablation (CA) has an established role in scar-related ventricular tachycardia (VT), but the risk of recurrences is substantial and the appropriate intensity of postablation monitoring unknown. The implication of timing of postablation VT recurrence has not been adequately investigated. Methods: We studied 120 consecutive patients with scar-related VT (age 60 15 years, left ventricular ejection fraction 39 16%, 52% ischemic etiology) with at least 2 years of follow-up. Timing of VT recurrence was classified as very early (<1 month), early (1-6 months), or late (>6 months). Results: At 24 months follow-up, 53 (44%) patients had recurrent VT, with eight (15%) having very early recurrence, 17 (32%) early recurrence, and 28 (53%) late recurrence. Mortality rates at 2 years were significantly higher in patients with very early VT recurrence (38%) compared to those with early (12%), late (7%), and no (3%) recurrences (log-rank P<0.001). Very early VT recurrence was associated with an increased risk of death (odds ratio=5.68, 95% confidence interval = 1.06-30.62, P=0.04), while recurrent VT beyond 6 months was not associated with increased risk of mortality (P=0.94). Conclusions: Timing of VT recurrence following CA of scar-related VT impacts subsequent risk of mortality. Patients experiencing VT recurrence within 1-6 months from the procedure are at particularly high risk. These data support the importance of intense postablation monitoring for at least 6 months after the procedure to identify patients with early VT recurrence who may benefit from additional therapeutic interventions to improve outcomes.