Early substrate-based catheter ablation vs. antiarrhythmic drug therapy for ventricular tachyarrhythmias among patients with prior myocardial infarction: the MANTRA-VT randomized trial

Abstract

Aims Ventricular tachyarrhythmias (VT/VF) are common among patients with prior myocardial infarction (MI). MANTRA-VT trial was designed to compare the efficacy and safety of early substrate-based radiofrequency catheter ablation (RFCA) to antiarrhythmic drug (AAD) therapy for ventricular tachyarrhythmias. Methods We randomly assigned 58 AAD naïve post MI patients with implantable cardioverter defibrillator (ICD) and at least one and results documented VT/VF episode after the device implantation to an initial treatment strategy of substrate-based RFCA or AAD therapy. The primary endpoint was cumulative number of ventricular tachyarrhythmias (VT/VF burden) at 12 months. The secondary endpoints included all-cause mortality, hospitalization, adverse events, and VT/VF burden at 24 months. Analyses were performed on an intention-to-treat basis. The median number of VT/VF episodes at 12 months was zero in both the RFCA (range 0–3) and the AAD group (range 0–23) (P = 0.454), whereas the rate of appropriate ICD shocks was 7% and 30% in the RFCA and the AAD groups (P = 0.026), respectively. During the extended follow-up, 82% of the patients in the RFCA group and 63% in the AAD group had no ICD therapies (P = 0.012). There was no significant difference between the groups in total mortality (HR 1.02, 95% CI 0.20–5.11, P = 0.86) and hospitalization (HR 1.35, 95% CI 0.36–5.09. P = 0.66) at 24 months. Therapy-related adverse events occurred in 3.6% and 16.7% of the patients in the RFCA and the AAD groups (P = 0.10), respectively. Conclusion Early substrate-based RFCA was associated with reduced risk of ICD therapies, but with no meaningful difference in VT/VF burden, mortality, hospitalization, and adverse events.