Immediate ventricular tachycardia ablation after first ICD shock may improve survival
ICD, Ablation soon after the first implantable cardioverter defibrillator shock for ventricular tachycardia conferred better event-free survival compared with standard care, a speaker reported.
Findings from the PARTITA trial, presented at the American College of Cardiology Scientific Session, indicated that ventricular tachycardia ablation within 2 months of first ICD shock was associated with lower risk for all-cause death and HF hospitalization during more than 2 years of follow-up compared with standard care.
“Current guidelines indicate ventricular tachycardia ablation in patients with structural heart disease and recurrent ventricular tachycardia episodes causing ICD interventions,” Paolo Della Bella, MD, head of the arrhythmia department at San Raffaele Hospital in Milan, said during the presentation. “Although observational studies have shown that freedom from ventricular tachycardia recurrence following ablation is associated with improved survival, the following issues concerning the role of ablation are still open questions to be addressed by prospective studies.
“Timing: Should we perform ablation prophylactically at the time of ICD implant, after the first shock or even after recurrent VT or electrical storm? And does the prevention of the ventricular tachycardia episode impact survival or occurrence of heart failure,” Della Bella said.
For this two-phase, prospective, randomized trial, researchers enrolled 517 patients with ischemic or nonischemic dilatative cardiomyopathy and an implanted ICD for the primary or secondary prevention of sudden cardiac death into an initial observational phase. Participants were enrolled into phase 2 when the first appropriate shock for ventricular tachycardia was delivered. Those in phase 2 were then randomly assigned to undergo ablation within 2 months or continuation of standard care. The primary endpoint was a composite of all-cause death or worsening HF leading to hospitalization. Researchers also evaluated a secondary endpoint of ventricular tachycardia recurrence with shock.
During a median follow-up of 2.4 years, 11% of participants received an appropriate shock and 9% underwent ablation in phase 2 of the trial.
Due to fewer than expected incidences of ventricular tachycardia, the trial design was amended to use a Bayesian approach that utilized interim analyses of patients with full follow-up.
The results were simultaneously published in Circulation.
Researchers reported that ablation after first ICD shock for ventricular tachycardia was associated with lower risk for the primary endpoint compared with standard care (HR = 0.11; 95% CI, 0.01-0.85; P = .037).
All-cause death occurred in 0% of the ablation arm and 33.3% of the standard care arm (P = .004). Worsening HF leading to hospitalization occurred in 4.3% of the ablation arm and 25% of the standard care arm (P = .053).
Ablation was also associated with fewer shocks for recurrent ventricular tachycardia compared with standard care (P = .039).
“In conclusion, the PARTITIA trial was prematurely stopped with a claim of superiority of ablation compared with standard treatment,” Della Bella said during the presentation. “Despite the limited sample size, our multicenter randomized trial indicated a 99% posterior probability of superiority of ventricular tachycardia ablation after the first episode of ventricular tachycardia treated with shock over a standard approach, both in terms of mortality and HF hospitalization.”