Efficacy and effects on cardiac function of radiofrequency catheter ablation vs. direct current cardioversion of persistent atrial fibrillation with left ventricular systolic dysfunction.

Objective: To evaluate the effect of catheter ablation vs. direct current synchronized cardioversion (DCC) in patients with persistent atrial fibrillation (AF) and left ventricular systolic dysfunction, and to define baseline features of patients that will get more benefit from ablation.

Methods: From July 2013 to October 2014, 97 consecutive single-center patients with persistent AF and symptomatic heart failure (left ventricular ejection fraction (LVEF) <50%) underwent DCC followed by amiodarone (n = 40) or circumferential pulmonary vein isolation (PVI; n = 57) according to patient's preference were recruited in the study. Post-ablation recurrence was treated with atrial roof and mitral isthmus lines ablation with or without PVI based on restoration or not of pulmonary vein (PV) potential conduction. Study outcomes were 12-month rate of sustained sinus rhythm (SR) and cardiac function. Baseline characteristics were compared between patients with and without cardiac function improvement post ablation.

Results: With similarly distributed characteristics at baseline, ablation (mean 1.8 procedures) relative to DCC yielded significantly higher level of 12-month SR maintenance rate (68.42% vs. 35%, P = 0.001); and better LVEF and New York Heart Association class. with significant effect for DCC only in maintained SR cases. Post ablation LVEF increased (>20% or to over 55%) in 31 (54.39%) patients with worse baseline cardiac function and ventricular rate control.

Conclusions: Catheter ablation relative to cardioversion of persistent AF with symptomatic heart failure yielded better 12-month SR maintenance and cardiac function. Compared with non-responders, patients with improved LVEF post-ablation had poorer ventricular rate control and cardiac function at baseline, suggesting a significant component of tachycardia-induced cardiomyopathy in this group.