Po-02-067 predictors and impact of pulmonary vein non-reconnection in the second procedure after ablation index-guided pulmonary vein isolation for atrial fibrillation

Reconnection of the pulmonary vein (PV) is the primary mechanism of atrial tachyarrhythmia (AT) recurrence after atrial fibrillation (AF) ablation. In patients with AT recurrence after the first ablation index (AI)-guided AF ablation, we examined the predictors of PV non-reconnection and its impact on the outcome after the second procedure. We aimed to elucidate the predictor of PV non-reconnection and its impact on the outcome after the second ablation procedure. Among the consecutive 2089 patients undergoing the first AI-guided AF ablation, we studied 289 with AT recurrence undergoing the second procedure. We compared clinical characteristics and outcomes between the patient groups with and without PV reconnection at the beginning of the second procedure. Of the 289 patients, 134 (46%) had non-reconnection, while the other 155 (54%) had reconnection at least in one PV. Patients' characteristics, including AF type (paroxysmal AF, 41% versus 48%; persistent AF, 28% versus 26%; long-standing persistent AF, 31% versus 26%, respectively, P=0.50), were similar between the two groups. The percentage of first-pass PV isolation (FPI) in both PV sides in the first ablation procedure was significantly higher in PV non-reconnection than in those with reconnection group (77% versus 43%, respectively, p<0.001). Multivariate logistic regression analysis revealed that FPI at the first procedure (odds ratio, 0.23 (95% confidence interval (CI), 0.13-0.38), p<0.001) was the only independent predictor of PV reconnection. After the second procedure, Kaplan-Meier analysis revealed that AT recurrence rate was significantly higher in patients with PV non-reconnection than in those with reconnection (Log-rank test, p=0.005). Multivariate Cox proportional hazard model analysis revealed that PV non-reconnection (hazard ratio (HR), 1.71 (95%CI, 1.14-2.55), p=0.008), left atrial dimension (1.04 (1.01-1.07), p=0.006), and left ventricular ejection fraction (0.98 (0.96-0.99), p=0.005) were independent predictors of AT recurrence. However, AF type was not: HR to paroxysmal AF (reference) was 1.10 (95%CI, 0.67-1.83) (p=0.70) in persistent AF and 1.30 (0.82-2.03) (p=0.26) in long-standing persistent AF. FPI in the first procedure was the only independent predictor of PV non-reconnection. After the second procedure, PV non-reconnection was an independent worsening predictor of AT recurrence, suggesting a need for an aggressive search for non-PV mechanisms.