Standard Ablation Versus Magnetic Resonance Imaging-Guided Ablation in the Treatment of Ventricular Tachycardia.

Abstract

Radiofrequency ablation is an effective treatment strategy for ischemic and nonischemic cardiomyopathy-related ventricular tachycardia (VT). The role of substrate-guided ablation, performed using electrogram characteristics (low amplitude, fractionated or isolated potentials) as scar surrogates, is expanding because of frequent hemodynamic instability during entrainment mapping of scar-related VT. Late gadolinium-enhancement on cardiac magnetic resonance imaging (LGE-MRI) can accurately characterize the transmural extent, location, and configuration of ventricular scar.1 Integration of LGE-MRI into electroanatomical mapping during VT ablation was shown, in preliminary studies, to be feasible and to provide accurate localization of VT substrate and reentry circuits.2–4 However, studies to date examining the impact of MRI scar integration on procedural outcomes have lacked control groups, precluding any comparisons with standard practice. We performed a study to (1) demonstrate the feasibility in clinical practice of integrating MRI-derived scar for guidance of VT ablation; (2) report on the periprocedural performance of LGE-MRI in identifying the arrhythmogenic substrate; and (3) examine the impact of MRI-guided ablation on procedural length and acute and long-term outcomes. In this prospective multicenter study, we enrolled 24 consecutive patients with ischemic (n=9) and nonischemic cardiomyopathy (n=15), referred for catheter ablation of scar-related monomorphic VT. Patients were assigned, at the discretion of the treating physician (not randomized), to undergo either MRI-derived scar–guided ablation or traditional ablation. Clinical characteristics of patients in both groups were statistically comparable with a higher tendency to use scar integration for patients with prior …