Time Interval From Right Atrium to Coronary Sinus Predicts Postablation Atrial Fibrillation Recurrence in Current Ablation Practice

BACKGROUND: Recurrence after ablation for atrial fibrillation (AF) may occur in patients in whom atrial remodeling progresses. Atrial conduction time is a marker of remodeling. This study investigated whether atrial conduction time is related to postoperative recurrence. METHODS AND RESULTS: This study enrolled 441 patients with AF (median age 69 years; 144 women; paroxysmal/non-paroxysmal AF=231/210) who underwent initial radiofrequency catheter ablation at Mie University Hospital between January 2018 and December 2022. The interval from the earliest potential in the right atrium (RA) to the latest potential in the coronary sinus (CS) was measured using a BeeAT catheter during sinus rhythm after ablation. The primary endpoint was AF recurrence or atrial tachycardia lasting >30 s in the 1 year after ablation. Recurrence was observed in 44 patients. Patients were categorized into 2 groups according to recurrence. The RA-CS interval was significantly longer in the recurrence group (122.5±17.7 vs. 98.5±17.7 ms; P<0.001). In Cox regression analysis, the RA-CS interval was independently associated with recurrence (hazard ratio 1.05; 95% confidence interval [CI] 1.03-1.07; P<0.001). The cut-off value for the RA-CS interval was 111 ms (area under the curve=0.845; 95% CI 0.785-0.905). The recurrence rate was significantly higher in patients with an RA-CS interval ≥111 vs. <111 ms. CONCLUSIONS: The RA-CS interval time was an independent predictor of recurrence after AF ablation.