F-wave vector magnitude predicts recurrence after catheter ablation of atrial fibrillation

Catheter ablation for atrial fibrillation (AF) carries a known risk of tachyarrhythmia recurrence, but the recurrence is still difficult to predict before the procedure. This study assessed the value of noninvasive f-wave vector magnitude (FVM) during AF in predicting recurrence following ablation.

This observational study included 604 consecutive patients who underwent initial AF ablation between January 2017 and December 2022 at Mitsubishi Kyoto Hospital, and whose baseline 12-lead electrocardiograms during AF were available. The maximal f-wave amplitude (FWA) over a 10-s period was measured manually using computerized calipers, and FVM was defined as the magnitude of atrial depolarization in three-dimensional space, calculated using the visually transformed Kors' quasi-orthogonal method. The outcome measure was the recurrence of atrial tachyarrhythmias after a 90-day post-procedural blanking period.

The median follow-up was 5.4 (3.9-7.1) years. In multivariable analysis, low FVM (< 0.18 mV) was an independent predictor of recurrence (hazard ratio [HR] = 1.56, 95% confidence interval [CI] = 1.16-2.15, p < 0.01) as well as left atrial dilatation (≥ 45 mm) (HR = 1.46, 95% CI = 1.08-1.98, p = 0.01). The 5-year recurrence-free rate after initial ablation was lowest in patients with both low FVM and left atrial dilatation (53.9%), and highest in those with neither (78.3%, p < 0.001). The risk stratification was only clear in patients with non-paroxysmal AF (49.4% vs. 79.9%, p < 0.001). In contrast, FWA below 0.10 mV in lead V1, defined as a fine f-wave, was not associated with recurrence following ablation.

Noninvasive FVM measurement stratified the risk of recurrence after AF ablation in patients with non-paroxysmal AF, but did not show predictive value in those with paroxysmal AF.