Defining the Outcome of Ventricular Tachycardia Ablation: Timing and Value of Programmed Ventricular Stimulation.

BACKGROUND: Catheter ablation of ventricular tachycardia (VT) is effective to prevent arrhythmia episode-related implantable cardioverter defibrillator shocks. However, recurrences in noninducible patients at programmed ventricular stimulation (PVS) are substantial. METHODS AND RESULTS: From May 2013 to September 2015, 218 PVSs were performed 6 days (5-7) after ablation (186 noninvasive programmed stimulations and 32 invasive PVS) in 210 consecutive patients (ischemic, 48%; median left ventricular ejection fraction, 37%; syncope, 35% with trauma associated 6%), while patients were awake and under beta-blocker therapy. After ablation, implantable cardioverter defibrillators were programmed according to noninvasive programmed stimulations results (class A-noninducible; class B-nondocumented inducible VT; and class C-documented inducible VT), with high and delayed VT detection intervals. Concordance between PVS end procedure and PVS day 6 was 67%. Positive predictive value and negative predictive value were higher for PVS day 6 (53% and 88% versus 43% and 71%). Ischemic and patients with preserved ejection fraction showed the highest negative predictive value (91% and 96%). Among 46 of 174 (26%) noninducible patients at PVS end procedure, but inducible at day 6, 59% had VT recurrence at 1-year follow-up; recurrences were 9% when both studies were noninducible. There were no inappropriate shocks; incidence of syncope was 3%; and none was harmful. The rate of appropriate shocks per patient per month according to noninvasive programmed stimulations results was significantly reduced, comparing the month before and after ablation (class A:2 [0.75-4] versus 0; class B:2 [1-4] versus 0; class C:2 [1-4] versus 0; P<0.001). CONCLUSIONS: PVS at day 6 predicts VT recurrence more accurately allowing to identify patients who might benefit from a redo ablation and addressing implantable cardioverter defibrillator programming.