Atrial fibrillation (AF) is the most common cardiac arrhythmia. Its prevalence is known to increase with age and with an aging population AF is likely to become even more common. Although sometimes patients with AF remain asymptomatic, it is now recognized that AF is far from “benign” conferring a significant risk increase in morbidity and mortality. Restoration of sinus rhythm and rate-limiting medication help with symptoms; however, anticoagulation remains essential in reducing thromboembolic risk. The uptake of appropriate anticoagulation with vitamin K antagonists has increased significantly in the last few decades and this review will analyze whether the new oral anticoagulants might prove to be even more effective than existing vitamin K antagonists. 1. Introduction Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting 1-2% of the general population [1]. Its prevalence can increase up to 15% [2] in people older than 80 years of age, and furthermore in some patient groups such as those with a permanent pacemaker, AF might have an even greater prevalence [3, 4]. The once considered “benign” arrhythmia is now recognized to increase mortality by twofold and the risk of stroke by fivefold leading to increased hospital admissions, reduced quality of life, impaired exercise capacity, tachycardia-induced cardiomyopathy, and heart failure [5]. Although restoration of sinus rhythm and rate-limiting medications are recognized to help with the symptoms associated with atrial fibrillation [6], appropriate anticoagulation is the major step in reducing stroke and thromboembolic risk [7]. 2. Anticoagulation in AF Warfarin, a vitamin K antagonist, is the most commonly utilized oral anticoagulant to reduce the risk of stroke and thromboembolism in patients with AF. It can lead to up to a 60% relative risk reduction of stroke and thromboembolic events compared to placebo and with an absolute risk reduction of 2.7% per year only 37 patients need to be anticoagulated to prevent one episode of stroke or thromboembolism [8]. It also compares favorably with aspirin [9] and dual therapy with aspirin plus clopidogrel [10] and is duly recommended in national and international guidelines (ESC, ACCP, AHA, NICE, SIGN [1, 11–14]). However, warfarin does have many side effects including unpredictable pharmacokinetics in response to food and drug interactions and therefore regular monitoring is required even in stable patients [15]. Therefore, new oral anticoagulants (NOACs) that have a predictable response and negate the need for regular blood monitoring offer
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