Ablation of Atrial Fibrillation Under Therapeutic Warfarin Reduces Periprocedural Complications

BACKGROUND: Observational data suggest that performing radiofrequency catheter ablation of atrial fibrillation (AF) under therapeutic warfarin (continuous warfarin CW) may reduce the periprocedural risk of complications, such as thromboembolic events, compared to warfarin discontinuation (DW) with periprocedural bridging with heparin. We systematically reviewed the available evidence on the impact of CW compared with DW on periprocedural complications of AF catheter ablation. METHODS AND RESULTS: We searched major Web databases for studies on radiofrequency catheter ablation of AF under CW versus DW with periprocedural bridging with heparin. Data on periprocedural complications were extracted. We identified 9 studies (1 large case series indirectly compared with the latest Worldwide Survey). A total of 27,402 patients were included in the analysis (6400 undergoing ablation with CW). CW was associated with a striking decrease of thromboembolic complications (OR, 0.10; 95% CI, 0.05-0.23; P<0.001) and minor bleeding complications (OR, 0.38; 95% CI, 0.21-0.71; P=0.002) compared with DW. CW also did not increase the risk of major bleeding (OR, 0.67; 95% CI, 0.31-1.43; P=0.30), including cardiac tamponade (OR, 0.69; 95% CI, 0.19-2.47; P=0.57). CONCLUSIONS: There is highly consistent evidence from observational studies that a CW strategy during radiofrequency catheter ablation of AF reduces the risk of thromboembolic complications without increasing the risk of bleeding.