Abstract 14622: Outcome of Ventricular Tachycardia Ablation in Patients with Nonischemic Dilated Cardiomyopathy: Impact of Noninducibility
INTRODUCTION Ablation failure and recurrence rates after VT ablation in nonischemic dilated cardiomyopathy (NICM) are high and the optimal procedural endpoint is not well defined. We analyzed the procedural endpoint, outcomes after ablation and predictors of VT recurrence.
METHODS Forty-five consecutive patients (pts) with NICM (60±16 years, 76% male, LVEF 44±14%) accepted for VT ablation were included. Twelve (27%) had prior endocardial ablation failure. Epicardial mapping was performed in 29 (64%). After the last radiofrequency application, the complete programmed electrical stimulation protocol (3 CL, 3 extrastimuli, burst, ≥2 sites) was repeated. Complete success was defined as non-inducibility of any monomorphic VT ; partial success as elimination of clinical VT (still non-clinical VT inducible); failure as inducibility of clinical VT. Pts were observed for 25±15 months.
RESULTS In 45 pts a median of 3 (IQR, 2 - 3) VTs (CL 342±77ms) was induced. Complete success was achieved in 17 (38%), partial success in 17 (38%), 6/17 due to non-clinical, non-targeted fast VT (CL<250ms); and failure in 11 pts (24%), 2/11 fast VT. VT occurred in 24 pts (53%) during follow-up but the 6-month VT burden was reduced by ≥75% in 79%. Recurrence rates were low after complete procedural success (18%), but high after both partial success (77%) and failure (73%). Five of 8 pts (63%) with only remaining fast VTs had recurrence. Independent predictors of recurrence were non-complete procedural success (HR 5.37, 95%-CI 1.48-19.51) and LVEF (HR 1.57 per 10% decrease, 95%-CI 1.10-2.25). Six pts (13%) died during follow-up.
CONCLUSIONS Although 53% of pts had VT during follow-up, 6-month VT burden was suppressed by ≥75% in 79%. Recurrence rates are low after complete procedural success, but high after both partial success and failure. Importantly, induction of fast VT after ablation appears not to be an innocent finding. Non-complete procedural success and LVEF predict VT recurrence.
- © 2012 by American Heart Association, Inc.