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).