Predicting outcomes in persistent atrial fibrillation: the impact of surface ECG f-wave amplitude following pulmonary vein isolation.

Background
Fibrillatory wave amplitude (fWA) on 12-lead ECG predicts the outcome of ablation in atrial fibrillation (AF). We hypothesized that changes in fWA following wide circumferential isolation of pulmonary veins (WPVI) in persistent AF (peAF) is a better predictor of ablation outcome compared to baseline fWA.Methods
Eighty-nine patients (sustained peAF 7 ± 7 months) underwent a first-time WPVI. Sixty-second ECG signals devoid of QRST waves were recorded at baseline and at the end of the WPVI (endWPVI). fWA for each ECG lead and mean fWA (meanfWA) across the 12-lead ECG were computed. Patients with recurrence after the index WPVI underwent a redo to ensure complete PVI. The primary endpoint was long-term AF freedom OFF antiarrhythmics drugs (AADs) after one or two WPVI (SUCCESS group). The FAILURE group was defined as AF recurrence post-redo.Results
Over a mean follow-up of 35 ± 10 months, freedom from AF OFF AADs was achieved in 61% (SUCCESS group), while 29% had AF recurrence after redo WPVI (FAILURE group). The SUCCESS group showed significantly higher fWA values in ECG leads V1, V4, and V5 at baseline (p < 0.05), as well as in leads III, aVL, aVF, and V4, and in meanfWA at endWPVI (p < 0.05) compared to the FAILURE group. A baseline mean fWA ≥ 0.044 mV or a decrease in mean fWA ≤ 11% following WPVI predicted long-term sinus rhythm restoration with a sensitivity of 81% and a specificity of 69% (p < 0.05).Conclusion
Low fWA values and a significant reduction in fWA following WPVI are associated with a high risk of AF recurrence in patients with peAF.