New anticoagulants for the prevention of stroke in atrial fibrillation

Oral anticoagulation in atrial fibrillation is obligatory to lower the risk of spontaneous cerebrovascular and systemic thromboembolism. For this purpose, vitamin K antagonists (coumarins) have been recommended as the most effective drugs for a long time. However, problems with the practical use of these agents, e.g. the need for frequent and regular coagulation controls, the inter‐individual differences in maintaining a stable therapeutic range, as well as drug or food interactions, have led to the search and investigation of alternative compounds characterized by a more simple use (e.g. without regular controls of therapeutic levels), high efficacy, as well as low risk of bleeding. The direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors rivaroxaban and apixaban have recently been investigated to prove whether they fulfill the high expectancy of an ideal anticoagulant with respect to a more favorable efficacy/safety profile and without the need for coagulation controls, thereby improving quality of life. Dabigatran (RE‐LY) achieved an impressive reduction in stroke and non‐central nervous system (non‐CNS) embolism (110 mg: 1.5%/year; 150 mg: 1.1%/year) in contrast to warfarin (1.7%/year; P = 0.34 and P < 0.001) with a favorable action on bleeding hazards. The results of rivaroxaban which were obtained in the ROCKET AF study (on treatment analysis: stroke and non‐CNS embolism: 1.7%/year vs. 2.15%/year with warfarin; P = 0.015; primary safety endpoint major and minor bleeding: 14.91 vs. 14.52%; P = 0.442) point in the same direction. And finally, compared to aspirin, apixaban reduced the combined primary efficacy endpoint by 52% with comparable rates of bleeding (AVERROES). This review gives a summary of the current knowledge about these agents and their potential future importance.     

Uninterrupted anticoagulation with non‐vitamin K antagonist oral anticoagulants in atrial fibrillation catheter ablation: Lessons learned from randomized trials

Catheter ablation has been established as a rhythm control strategy in selected patients with atrial fibrillation (AF) who have failed or wish to avoid anti‐arrhythmic drugs. Uninterrupted oral anticoagulation with vitamin K antagonists (VKAs) peri‐ablation is associated with a lower risk of thromboembolic and bleeding complications as compared to interrupted oral anticoagulation and bridging heparin. However, a substantial portion of patients with AF are treated with non‐vitamin K antagonist oral anticoagulants (NOACs). Herein, we perform an in‐depth review and comparison of three recent randomized trials of uninterrupted oral anticoagulation with NOACs vs VKAs in patients undergoing AF catheter ablation. Furthermore, we report pooled results of these randomized trials. The pooled incidence of major bleeding was significantly lower with NOACs as compared to VKAs (2% vs 4.9%, respectively; odds ratio [OR] 0.40; 95% confidence intervals [CI] 0.16‐0.99). Similarly, cardiac tamponade was also reduced in the NOAC group (0.4% vs 1.5%; OR 0.27; 95% CI 0.07‐0.97). Thromboembolic complications were not significantly different between groups. Overall, these findings support the 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement's class I recommendation for uninterrupted NOAC use in patients undergoing AF catheter ablation.