Reassessing Noninducibility as Ablation Endpoint of Post-Infarction Ventricular Tachycardia

Abstract

Background— Noninducibility is frequently used as procedural end point of ventricular tachycardia (VT) ablation after myocardial infarction. We investigated the influence of left ventricular (LV) function on the predictive value of noninducibility for VT recurrence and cardiac mortality. Methods and Results— Ninety-one patients (82 men, 67±10 years) with post–myocardial infarction VT underwent ablation between 2009 and 2012. Fifty-nine (65%) had an LV ejection fraction (EF) >30% (mean 41±7) and 32 (35%) an LVEF≤30% (mean 20±5). Thirty patients (51%) with EF>30% and 13 (41%) with EF≤30% were noninducible after ablation ( P =0.386). During a median follow-up of 23 (Q1–Q3 16–36) months, 35 patients (38%) experienced VT recurrences and 17 (18%) cardiac death. At 1 year follow-up, survival free from VT recurrence and cardiac death for patients with LVEF>30% was 80% (95% confidence interval [CI], 70–90) compared with 42% (95% CI, 33–51) for those with LVEF≤30% ( P =0.001). Noninducible patients with LVEF>30% had a recurrence-free survival from cardiac death of 90% (95% CI, 71–100) compared with 65% (95% CI, 47–83) for inducible patients ( P =0.015). In the subgroup of patients with LVEF≤30%, the survival free from VT recurrence and cardiac death was 31% (95% CI, 0%–60%) for noninducible compared with 39% (95% CI, 27–52) for those who remained inducible ( P =0.842). Conclusions— Noninducible patients with moderately depressed LV function have a favorable outcome compared with patients who remained inducible after ablation. On the contrary, patients with severely depressed LV function have a poor prognosis independent of the acute procedural outcome.