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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.