Six-Year Follow-Up Outcomes of Catheter Ablation of Para-Hisian Accessory Pathways.

Background: Ablation of para-hisian accessory pathways (APs) remains challenging due to anatomic characteristics, and a few studies have focused on the causes for recurrence of radiofrequency ablation of para-hisian APs. Objective: This retrospective single center study aimed to explore the risk factors for recurrence of para-hisian APs. Methods: One hundred thirteen patients who had para-hisian AP with an acute success were enrolled in the study. In the 6-year follow-up, 15 cases had a recurrent para-hisian AP. Therefore, 98 patients were classified into the success group, while 15 patients were classified into the recurrence group. Demographic and ablation characteristics were analyzed. Results: Gender difference was similar in two groups. The median age was 36.2 years old and was younger in the recurrence group. Maximum ablation power was significantly higher in the success group (29 ± 7.5 vs. 22.9 ± 7.8, p < 0.01). Ablation time of final target sites was found to be markedly higher in the success group (123.4 ± 53.1 vs. 86.7 ± 58.3, p < 0.05). Ablation time <60 s was detected in 12 (12.2%) cases in the success group and 7 (46.7%) cases in the recurrence group (p < 0.01). Occurrence of junctional rhythm was significantly higher in the recurrence group (25.5% vs. 53.3%, p < 0.05). No severe conduction block, no pacemaker implantation, and no stroke were reported. Junctional rhythm during ablation (OR = 3.833, 95% CI 1.083-13.572, p = 0.037) and ablation time <60 s (OR = 5.487, 95% CI 1.411-21.340, p = 0.014) were independent risk factors for the recurrence of para-hisian AP. Conclusions: With careful and accurate mapping, it is relatively safe to ablate para-hisian AP. If possible, proper extension of ablation time could reduce the recurrence rate of para-hisian APs.