Ablation of Atrial Fibrillation

Abstract

Atrial fibrillation (AF) ablation remains suboptimal—despite spectacular results in individual patients—for both persistent and paroxysmal AF using contemporary catheters.1 The benefits of pulmonary vein isolation (PVI) likely extend beyond isolating triggers because ablation may be more successful if wide areas are ablated by radiofrequency or cryoballoons,2 and patients without AF may have reconnected pulmonary veins.3 Hence, it seems intuitive that additional lesion sets should improve outcomes. Article see p 1316 However, several meta-analyses have suggested that commonly applied ablation sets beyond PVI provide inconsistent benefit.4 This was illustrated vividly by the Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Part 2 (STAR-AF2) trial, in which the 59% success of PVI was not improved by adding lines or targeting Complex Fractionated Atrial Electrograms (CFAE).5 However, a major criticism of STAR-AF2 is that lines were not blocked in 26% of patients. Into this arena comes the No Benefit of Complex Fractionated Atrial Electrogram Ablation in Addition to Circumferential Pulmonary Vein Ablation and Linear Ablation (BOCA) trial of ablation strategies for persistent and long-standing persistent AF in this issue of Circulation: Arrhythmia and Electrophysiology .6 BOCA addresses 2 unanswered questions: what is ablation success when lines are proven to be complete, and what is the value of supplementary widespread ablation (CFAE) if lines are blocked? In BOCA, the investigators prospectively randomized 131 persistent AF patients in 1:1 fashion to PVI+lines (roof and mitral, control) or PVI+lines+CFAE (CFAE). Conduction block was confirmed in 95% of mitral lines and 100% of roof lines and PVI. The investigators found that patients in the CFAE arm had no advantage over the control arm, with similar single (46.2% versus 56.9%, P =0.20) and multiprocedure (78% versus 80%, P =1.0) freedom from atrial arrhythmias at 12 months. Patients …