New oral anticoagulants in nonvalvular atrial fibrillation

Abstract

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and its incidence is 1-2% of the world's population. Atrial fibrillation is associated with an increased risk of morbidity and mortality, primarily due to an increased risk of stroke that is five times higher than in the general population. Therefore, life-long anticoagulant therapy is indicated in patients with atrial fibrillation in the prevention of stroke when CHA2DS2-VASc [congestive heart failure, hypertension, age > 75 years, diabetes mellitus, stroke, vascular disease, age 65-74 years, gender (female)] score > 2 in men and > 3 in women. For last ten years, anticoagulant therapy involved the use of vitamin K antagonists, primarily warfarin. Until the appearance of non-vitamin K oral anticoagulants (NOACs), that do not require routine efficacy monitoring and have more favorable pharmacological profile, warfarin use is significantly reduced in non-valvular AF. By the year 2017. the percentage of patients on NOAC-s exceeded the number of those on warfarin worldwide. Four NOAC-s are approved for use in patients with AF of nonvalvular origin in Europe: apixaban, dabigatran, edoxaban and rivaroxaban. Evidence from phase III studies suggests that NOAC-s are more effective and safer than warfarin. The most prescribed NOAC in almost all "real life" studies from the USA was rivaroxaban. For rivaroxaban "real life data" such as the XANTUS study show that the incidence of stroke and major bleeding is low (0.7 and 2.1 events per 100 patients / year). The efficacy of rivaroxaban in nonvalvular AF was first demonstrated in the ROCKET-AF large, multicenter, randomized, double-blind study in 14,264 patients. Rivaroxaban was non-inferior to warfarin in the prevention of ischemic stroke and systemic embolism. The overall percentages of major and clinically relevant non-major haemorrhages did not differ between rivaroxaban and warfarin, but there were fewer intracranial or fatal haemorrhages in the rivaroxaban group (0,5% vs 0,7% per year, HR 0,67, 95% CI 0,47-0,93, p = 0,02).