Short-term effectiveness and safety of ablation index guided high-power ablation using single ablation catheter in patients with atrial fibrillation

Objective To investigate the safety and effectiveness of ablation index (AI) guided high-power ablation using single ablation catheter for pulmonary vein isolation (PVI). Methods A total of 77 patients who underwent catheter ablation for atrial fibrillation were selected and their clinical data were retrospectively analyzed. They were divided into two groups: a high-power (HP) ablation using single ablation catheter group and a conventional power (CP) group. Both groups underwent PVI guided by AI. Patients in the CP group received standard protocol (SmartTouch catheter and circular mapping catheter), while those in the HP group used single ablation catheter (SmartTouch Surrounding Flow). Furthermore, the target values of AI were 450-500 for the anterior wall, 400-450 for the top wall and 350-400 for the posterior wall and inferior wall. The end point of ablation was the isolation of the bilateral pulmonary vein, that is bidirectional block of the atrium and pulmonary vein. Both groups were compared for basic information, ablation parameters (ablation time per lesion, the rate of impendence drop, PVI time, total surgical time, the single shot isolation rate of the left/right pulmonary vein and saline irrigation volume), complications and the recurrence rate at 6-month follow-up. Results There were no significant differences in the patients' baseline data between the CP group and the HP group (P>0.05). Compared with the CP group, the HP group showed remarkable decreases in PVI time and total surgical time (P<0.05), decreases in the rate of impendence drop (P<0.01), and decreases in saline irrigation volume (P<0.01), while the single shot isolation rate of the left/right pulmonary vein in the HP group increases, without statistical differences (P>0.05). All the patients successfully finished 6-month follow-up, while one case of groin hematoma was observed in the CP group. There was no statistical difference in the success rate of maintaining sinus rhythm between the two groups (P>0.05). For persistent atrial fibrillation, the success rate was higher in the HP group than the CP group, without statistical difference (P>0.05). Conclusions Compared with conventional PVI, AI-guided high power ablation using single ablation catheter is safe and effective, with shortened PVI time and surgical time.