Prospective evaluation of low voltage-guided repeat ablation of atrial fibrillation

Atrial fibrillation (AF) recurrences following pulmonary vein isolation (PVI) remain a substantial challenge.

To evaluate repeat ablation of AF combining PVI with substrate-based left atrial ablation targeting low voltage areas (LVA).

Patients with recurrent AF after prior solely PVI were enrolled. Voltage map was conducted during sinus rhythm. Repeat PVI was performed in case of PV-reconnection. Only if LVA (defined as electrogram amplitudes < 0.5 mV) were present, substrate modification was conducted by creating linear or box lesions. Arrhythmia monitoring was performed for 6 months using a photoplethysmography-based smartphone application.

58 patients were analysed (37.9% female, median age 66.0 years [IQR 59.8-72.3]). Reconnection of at least 1 PV was found in 49 patients (84.5%). LVA were found in 31 patients (53.4%). An anterior box lesion was created in 39.7%, anterior linear lesion in 8.6%, posterior box lesion in 17.2%, roof line in 34.5%, and posterior mitral isthmus line in 5.2% of the patients. Patients with LVA were more often female (54.8% vs. 18.5% without LVA; p = 0.0045), were at higher age (71.0 years [IQR 66.0-78.0] vs. 62.0 years [IQR 55.0-66.0] without LVA; p < 0.0001), and had higher left atrial volume indexes (50.0ml/m² [IQR 40.0-61.0] vs. 34.0ml/m² [IQR 28.0-48.0] without LVA; p = 0.0014). Arrhythmia-free survival was 66.7% in patients without LVA and 48.4% in patients with LVA (HR 0.6063; 95% CI:0.2767-1.329; p = 0.2206).

PV reconnection and the presence of LVA constitute the main findings of repeat ablations of AF. Repeat PVI combined with a tailored ablation approach individually targeting LVA was effective and safe.