The aim of this study was to identify the factors associated with bleeding complications in patients taking apixaban and undergoing a catheter ablation in everyday clinical practice.

AMPER ABLATION is a multicenter, observational, prospective study of patients with non-valvular atrial fibrillation (AF) undergoing a catheter ablation. Eligible patients had been taking apixaban (2.5 or 5mg twice daily) for ≥3 weeks before the procedure and were followed for 30 days afterwards.

A total of 595 patients (65[interquartile range 59, 72] years, 67% male, mean CHA2DS2-VASc score 1.85±1.37) were enrolled at 25 academic/nonacademic centers in France; 524 patients (88%) were receiving apixaban 10mg/day and 71(12%) 5mg/day. 323 patients (54%) underwent an AF ablation, and 272 (46%) an atrial flutter (AFL) ablation. Mean creatinine clearance (Cockcroft-Gault) was 82±34mL/min. Overall, 264 patients were switched to unfractionated heparin or enoxaparin (238 for AF ablations and 26 for AFL ablations). The median duration of switch was 29hours Complications were reported at 30 days, and included 12 bleeding events (1 tamponade needing drainage,1 pericardial effusion without drainage, 7 International Society on Thrombosis and Haemostasis [ISTH] non major bleedings for AF ablations and 1 pericardial effusion without drainage, and 2 ISTH non-major bleedings for AFL ablations) and 1 embolic event (non disabling stroke for an AF ablation). Comparing patients with and without a bleeding event revealed a higher rate of heparin or low-molecular-weight heparin (LMWH) switching in patients with a bleeding event (60% vs. 35%; P=0.02). A switch to heparin or LMWH was the only factor associated with an increase rate of bleeding (odds ratio 2.5; [CI 95%; 1.1], 7.1; P=0.01).

Heparin or LMWH switch in the periprocedural AF and AFL-ablation period is associated with an increased rate of bleeding complications at 30 days.