Study on efficacy, recurrence rate and related risk factors between ablation index and contact force guided radiofrequency ablation of paroxysmal atrial fibrillation in elderly patients

Abstract

Objective: To compare the efficacy, safety and recurrence rate between ablation index (AI) and contact force (CF) guided radiofrequency ablation of paroxysmal atrial fibrillation in elderly patients. Methods: Elderly patients (age ≥60 years) with paroxysmal atrial fibrillation who received radiofrequency ablation for the first time at Department of Cardiology, Beijing Friendship Hospital from April 2018 to April 2019 were enrolled. Patients were divided into 2 groups: AI-group (n=40) and CF group (n=37) depending on their ablation methods. Follow-up was performed until 1 year post the procedure, and efficacy related indexes like first-pass pulmonary vein isolation (PVI) rate, ablation duration, operation duration and major complications were compared between 2 groups. The recurrence rates between 2 groups and related risk factors after radiofrequency ablation were analyzed. Results: A total of 77 patients [mean age (68.5±6.4) years, 40 were male] were enrolled at last. In AI guided patients, frequency of first-pass PVI rate was higher [52.5%(21 cases) vs 29.7%(3 cases), P=0.011] with a shorter ablation duration [(24.5±1.7) min vs (33.7±2.2) min, P<0.001] and operation duration [(136.6±6.1) min vs (139.7±7.4) min, P=0.048] compared with CF guided group. At 1 year follow-up, AI group showed an amendatory recurrence rate in Kaplan-Meier analysis (22.5% vs 40.5%,log-rank P=0.048). Multivariate Cox regression analysis showed that CF guided ablation (HR=3.272,95%CI:1.319-8.114,P=0.011), enlarged anteroposterior diameter of the left atrium (HR=4.233,95%CI:1.511-11.862,P=0.006) and complicated with coronary heart disease (HR=4.829,95%CI:1.399-16.666,P=0.013) were independent risk factors for recurrence of atrial fibrillation in elderly patients. Conclusions: Compared with CF guided ablation, radiofrequency ablation of paroxysmal atrial fibrillation in elderly patients guided by AI showed a higher first-pass PVI rate, shorter procedure duration of both ablation time and total operation time, meanwhile a lower recurrence rate. Further analysis revealed that different ablation alternation (AI or CF), enlarged anteroposterior diameter of left atrium, and complicated with coronary heart disease are independent risk factors for recurrence after radiofrequency ablation of atrial fibrillation in elderly patients.