Safety and efficacy of ablation index-guided high-power ablation for the treatment of atrial fibrillation.

Objective: To study the safety and efficacy of high-power ablation for atrial fibrillation (AF) guided by lesion size index (LSI) and impedance cutoff.

Method: A total of 223 patients who underwent radiofrequency catheter ablation of atrial fibrillation (including paroxyparal atrial fibrillation and persistent atrial fibrillation) in the Department of Cardiology of Anhui Provincial Hospital from February 2019 to July 2020 were enrolled, and were divided into 123 patients in the high-power ablation group (HPAI) and 100 patients in the conventional power ablation group (CPAI). The HPAI group adopted high-power (40-50 W) ablation by impedance cutoff, and the CPAI group adopted conventional-power (30-35 W) ablation. Patients in both groups were ablated guided by the same LSI. For both groups, we analyzed the pulmonary vein single-circle isolation rate, ablation time, X-ray exposure, impedance drop value, incidence of complications, and recurrence rate within one year after operation.

Results: There was no significant difference in the success rate of pulmonary vein single-circle isolation, X-ray perspective time, and X-ray exposure quantity between the HPAI group and the CPAI group (88.60% vs 82.00%,  = 0.161; 8.7 ± 3.74 min vs 7.82 ± 3.86 min,  = 0.067; 54.74 ± 28 min vs 52.78 ± 39.58 min,  = 0.139); the annular pulmonary vein ablation time and total ablation time were less in the HPAI group (35.74 ± 7.25 min vs 65.49 ± 7.34 min,  < 0.01; 55.42 ± 11.61 min vs 76.9 ± 6.79 min,  < 0.01); the impedance drop values at 10-15Ω and 15-20Ω were higher in the HPAI group (25.3% vs 19.1%,  < 0.05; 24.1% vs 19.1%,  < 0.05); there was no significant difference in the recurrence rate within one year after operation between the two groups; and no serious complications occurred in the two groups.

Conclusion: High-power ablation guided by LSI and impedance cutoff could significantly shorten the AF ablation time and reduce complications.