Venturing into ventricular arrhythmia storm: a systematic review and meta-analysis

Ablation has substantial evidence base in the management of ventricular arrhythmia (VA). It can be a 'lifesaving' procedure in the acute setting of VA storm. Current reports on ablation in VA storm are in the form of small series and have relative small representation in a large observational series. The purpose of this study was to systematically synthesize the available literature to appreciate the efficacy and safety of ablation in the setting of VA storm. The medical electronic databases through 31 January 2012 were searched. Ventricular arrhythmia storm was defined as recurrent (≥3 episodes or defibrillator therapies in 24 h) or incessant (continuous >12 h) VA. Studies reporting data on VA storm patients at the individual or study level were included. A total of 471 VA storm patients from 39 publications were collated for the analysis. All VAs were successfully ablated in 72% [95% confidence interval (CI) 71-89%] and 9% (95% CI: 3-10%) had a failed procedure. Procedure-related mortality occurred in three patients (0.6%). Only 6% patients had a recurrence of VA storm. The recurrence of VA was significantly higher after ablation for arrhythmic storm of monomorphic ventricular tachycardia (VT) relative to ventricular fibrillation or polymorphic VT with underlying cardiomyopathy (odds ratio 3.76; 95% CI: 1.65-8.57; P = 0.002). During the follow-up (61 ± 37 weeks), 17% of patients died (heart failure 62%, arrhythmias 23%, and non-cardiac 15%) with 55% deaths occurring within 12 weeks of intervention. The odds of death were four times higher after a failed procedure compared with those with a successful procedure (95% CI: 2.04-8.01, P < 0.001). Ventricular arrhythmia storm ablation has high-acute success rates, with a low rate of recurrent storms. Heart failure is the dominant cause of death in the long term. Failure of the acute procedure carries a high mortality.