Catheter ablation as a first-line treatment for ventricular tachycardia (VT) at the time of ICD implantation has not been incorporated into clinical recommendations. Furthermore, there was an unmet clinical need to investigate the function of VT ablation in patients with non-ischemic cardiomyopathy (NICM), a growing group referred for advanced therapy internationally. For a study, researchers sought to evaluate the role of early, first-line ablation treatment, they undertook an international, multi-center, randomized controlled study including 180 patients with cardiomyopathy with monomorphic VT who were candidates for implantable cardioverter-defibrillator (ICD) installation. A total of 121 individuals were randomly assigned (1:1) to either ablation plus an ICD or conventional medical treatment plus an ICD. After stand-alone ablation therapy, patients who declined ICD (n=47) were monitored in a prospective registry. The main endpoint was a composite of recurrence of VT, cardiovascular hospitalization, or death.

The randomized patients had a mean age of 55 years (IQR 46-64) and a left ventricular ejection fraction of 40% (IQR 30-49%); 81% were male. In 35% of cases, the underlying cardiac disease was ischemic cardiomyopathy (ICM), 30% had NICM, and 35% had arrhythmogenic cardiomyopathy (ARVC). Ablation was conducted on average two days before ICD placement (IQR 5 days prior to 14 days after). The main outcome occurred in 49.3% of the ablation group and 65.5% of the control group at 31 months (HR 0.58, 95% CI, 0.35-0.96; P=0.04). The observed difference resulted from a decrease in VT recurrence in the ablation group (HR 0.51 [95% CI, 0.29-0.90]; P=0.02). Patients who had ablation had a statistically significant reduction in both ICD shocks (10.0 vs 24.6%; P=0.03) and anti-tachycardia pacing (16.2% vs 32.8%; P=0.04) when compared to controls. There were no changes in cardiovascular hospitalization (32.0 vs. 33.7 %; HR 0.82 [95% CI, 0.43-1.56]; P=0.55) or death (8.9 vs. 8.8 %, HR 1.40 [95% CI, 0.38-5.22]; P=0.62]). Complications after ablation occurred in 8.3% of individuals.

Early catheter ablation conducted at the time of ICD implantation significantly decreased the composite primary outcome of VT recurrence, cardiovascular hospitalization, or mortality in individuals with cardiomyopathy of various etiologies. The findings were influenced by a decrease in ICD therapy.