Efficacy and safety of non-vitamin K antagonist oral anticoagulants one year after electrical cardioversion

Introduction: Atrial fibrillation (AF) is the most common arrhythmia in the world, affecting around 33 million people. Warfarin has been the anticoagulant of choice for the prevention of ischemic stroke in AF patients for a long time. Several large studies have shown that non-vitamin K antagonist oral anticoagulants (NOACs) offer numerous advantages regarding safety and effectiveness, such as fixed dose and more predictable pharmacokinetics. Methods: The study was conducted at Pauls Stradins Clinical University Hospital, Latvian Centre of Cardiology. The study took place from October 2015 to June 2017. A total of 356 patients who had undergone electrical cardioversion (ECV) was included in this study. Results: One year after ECV, 27.5% of patients used warfarin, 33.7% of patients used NOACs, whereas 38.8% did not use any oral anticoagulants. Nine (2.5%) of the patients who participated in the study died during the following year. Overall, eight patients (2.2%) suffered from significant bleeding and three patients (0.8%) had a non-fatal ischemic stroke. The rate of non-fatal ischemic stroke in patients who used warfarin was 2% and no cases were observed in patients who used NOACs (p = 0.20). The rate of significant bleeding was 5.1% versus 2.5% in warfarin and NOAC groups, respectively (p = 0.12). Conclusions: Compared with similar studies, our study showed a low rate of ischemic stroke and significant bleeding, and a low total death rate. One year after ECV, the use of warfarin decreased by 2.8% (p = 0.63), the use of rivaroxaban and dabigatran decreased by 17.5% (p = 0.001) and 17.4% (p = 0.001). The study shows that NOACs are a safe and effective alternative to warfarin.