Pulmonary vein isolation and low-voltage areas ablation in sinus rhythm for persistent atrial fibrillation (SCAR-AF study)

Substrate ablation strategies in addition to pulmonary vein isolation (PVI) for the maintenance of sinus rhythm (SR) are still debated. Targeting low voltage areas (LVA) in addition to PVI may represent an efficient strategy for the ablation of persistent atrial fibrillation (AF).

SCAR-AF study (ablation of LVA during sinus rhythm) was a multicenter, prospective, randomized trial, evaluating the effect of LVA ablation in addition to PVI for persistent AF on SR maintenance.

From September 2019 to August 2021, patients with de novo persistent AF were included in the study. After LA mapping guided by a 3D mapping system, patients were divided according to the presence or absence of LVA. Patients without LVA were treated by PVI only (Group A). Patients with LVA were randomized to PVI only (Group B) or PVI + ablation of LVA (Group C). LVA was defined as voltage mapping with bipolar atrial voltage <0.5 mV. The primary endpoint was freedom from atrial arrhythmias, after a single ablation procedure.

A total of 211 patients (Sex male: 73%, Mean Age 63.8+/-9.3 years, CHADS-VASC 2.1, long standing AF 33.5%). After 18 months FU, atrial-arrhythmia-free survival did not differ significantly between the 3 groups, 79% in Group A, 75.7% in Group B, 73.1% in Group C (Group A vs Group B: HR: 1.28; 95% CI: 0.64-2.55, p = .48, Group B vs Group C: HR 95%CI: 0.67-2.45; p = 0.45). Multivariate analysis showed that presence of LVA was associated with age (years) (HR 1.11 CI 1.06 – 1.16, p < 0.001) and inversely correlated with BMI (kg/m²) (HR 0.93, CI 0.87 – 0.99, p 0.029) and current smoking.

In this randomized trial, PVI plus ablation of LVA did not significantly improved outcomes in patients with persistent AF. LVA may represent a marker of severe atrial cardiomyopathy.