All-cause mortality and appropriate implantable cardioverter-defibrillator shocks with first-line catheter ablation versus antiarrhythmic drugs in ischemic ventricular tachycardia: A systematic review and Meta-analysis of randomized controlled trials.
TL;DR
In antiarrhythmic-naïve patients with ischemic cardiomyopathy and VT, first-line catheter ablation reduced appropriate ICD shocks but did not demonstrate a statistically significant reduction in all-cause mortality.
Abstract
Background
Ventricular tachycardia (VT) in ischemic cardiomyopathy is associated with recurrent implantable cardioverter-defibrillator (ICD) therapies, heart failure progression, and excess mortality. Randomized trials have shown that first-line catheter ablation reduces recurrent ventricular arrhythmia, but none was individually powered to detect realistic differences in all-cause mortality.
Methods
We performed a systematic review and meta-analysis of randomized controlled trials comparing first-line catheter ablation with antiarrhythmic drug (AAD) therapy in antiarrhythmic-naïve patients with ischemic cardiomyopathy and ICD-confirmed VT. The principal outcomes were all-cause mortality and appropriate ICD shocks, analyzed separately. Secondary outcomes included VT storm and heart failure hospitalization.
Results
Three multicenter trials (SURVIVE-VT, VANISH-2, and MANTRA-VT) enrolling 618 patients were included. All-cause mortality did not differ significantly between treatment strategies (RR 0.88, 95% CI 0.63-1.22; P = 0.434). Because follow-up duration differed across trials, a parallel time-to-event meta-analysis using hazard ratios from the original trial reports was also performed and showed a concordant direction of effect (HR 0.84, 95% CI 0.58-1.22; P = 0.36). Appropriate ICD shocks were significantly reduced with catheter ablation compared with AAD therapy (RR 0.76, 95% CI 0.59-0.98; P = 0.033). VT storm (RR 0.88, 95% CI 0.62-1.24; P = 0.46) and heart failure hospitalization (RR 0.78, 95% CI 0.36-1.71; P = 0.53) did not differ significantly. A post-hoc power calculation indicated that the mortality analysis remained substantially underpowered.
Conclusions
In antiarrhythmic-naïve patients with ischemic cardiomyopathy and VT, first-line catheter ablation reduced appropriate ICD shocks but did not demonstrate a statistically significant reduction in all-cause mortality. The available randomized evidence remains underpowered for firm conclusions regarding survival.