Randomized controlled trials
The efficacy of substrate modification through ablation of LVAs has been more mixed when evaluated in randomized trials. Wang et al., randomized 124 patients with long-standing persistent AF to either standard ablation, consisting of PVI with further linear and CFAE ablation aiming for AF termination, or a VGA strategy (24). At 12 months VGA was associated with significantly improved rates of freedom from AF and lower rates of post-ablation atrial tachycardia. Hindricks and colleagues also reported improved arrhythmia free survival in a mixed cohort of patients with either paroxysmal or persistent AF randomized to either LVA ablation or standard therapy (25). In a recent multi-center randomized trial, VGA for patients undergoing first ablation for PsAF was superior to PVI alone (26).
In a multi-center study, Yang et al. randomized 229 patients with non-paroxysmal AF to VGA in a technique similar their earlier observational study (23), or PVI plus linear ablation (27). The authors reported no difference in outcomes between the two groups. In the study by Kumagai et al., 54 patients with non-paroxysmal AF and LVAs on EAM were randomized to either PVI, posterior wall isolation and LVA ablation or PVI plus posterior wall isolation (28). LVA ablation in addition to isolation of the posterior wall did not demonstrate an additive effect in improving freedom from atrial arrhythmias. The presence of LVAs was associated with adverse outcomes in another randomized study of PAF, however ablation targeting these did not improve freedom from AF during early (29) or extended follow-up (30).