Novel Anticoagulants in Atrial Fibrillation: A Primer for the Primary Physician

Atrial fibrillation is a common arrhythmia encountered in clinical practice. The prevalence increases with age. A devastating complication of atrial fibrillation is cardioembolic stroke with central nervous system sequelae. Based on stroke risk scores (CHADS and CHA2DS2VASc) and bleeding risk (HAS-BLED), the optimal use of anticoagulation in atrial fibrillation is feasible. Warfarin is a proven medication for this specific indication but requires frequent monitoring and dose adjustments, and it has multiple food, drug, and disease-state interactions. In addition, management of anticoagulation during the perioperative period may be challenging. In this regard, novel oral anticoagulants (NOACs) have shown promise in the shift toward the "ideal" anticoagulant therapy, in that fixed dosing is the norm, drug interactions are few, food interactions are absent, onset is fairly immediate and offset predictable, and, in the majority of patients, therapeutic monitoring is not required. This article provides a review of recent published trials of the use of NOACs in atrial fibrillation. Practical points on indications, contraindications, mechanism of action, interactions, and perioperative management tips are discussed with a view toward the safe and effective use of these new medications. When patients are transitioned between different anticoagulant medications, the risks of thrombosis and bleeding need to be considered. When switching from warfarin to a NOAC, the NOAC can be started once the international normalized ratio is ≤2.0.