The safety of discontinuation of oral anticoagulation therapy after apparently successful atrial fibrillation ablation: a report from the Chinese Atrial Fibrillation Registry study.

Abstract

We aimed to investigate the safety of discontinuing oral anticoagulation (OAC) therapy after apparently successful atrial fibrillation (AF) ablation, using data from the Chinese Atrial Fibrillation Registry study. We identified 4512 consecutive patients who underwent successful AF ablation between August 2011 and December 2017. Of them, 3149 discontinued OAC 3 months post-ablation (Off-OAC group) and 1363 continued OAC beyond this period (On-OAC group). Regular follow-up examinations were undertaken to detect AF recurrence, monitor OAC therapy, and measure clinical outcomes. Primary outcomes included thromboembolic and major bleeding (MB) events experienced beyond 3 months after ablation. Low thromboembolic and MB event rates were noted in the on-treatment analysis. The incidence rates for thromboembolism were 0.54 [95% confidence interval (CI) 0.39-0.76] and 0.86 (95% CI 0.56-1.30) per 100 patient-years, and that for MB events were 0.19 (95% CI 0.11-0.34) and 0.35 (95% CI 0.18-0.67) per 100 patient-years, for the Off-OAC and On-OAC groups over mean follow-up periods of 24.2 ± 14.7 and 23.0 ± 13.6 months, respectively. Similar results were observed in the intention-to-treat analysis. Previous history of ischaemic stroke (IS)/transient ischaemic attack (TIA)/systemic embolism (SE) [hazard ratio (HR) 3.40, 95% CI 1.92-6.02; P < 0.01] and diabetes mellitus (HR 2.06, 95% CI 1.20-3.55, P = 0.01) were independently associated with thromboembolic events, while OAC discontinuation (HR 0.71, 95% CI 0.41-1.23, P = 0.21) remained insignificant in multivariable analysis. This study suggests that it may be safe to discontinue OAC in post-ablation patients under diligent monitoring, in the absence of AF recurrence, history of IS/TIA/SE, and diabetes mellitus. However, further large-scale randomized trials are required to confirm this. Chinese Clinical Trial Registry ChiCTR-OCH-13003729. URL: http://www.chictr.org.cn/showproj.aspx?proj=5831.