Antithrombotic Therapy in Atrial Fibrillation: A Review of Current Guidelines, Anticoagulant Options, and Bleeding Risk

Research Article

Abstract

Atrial fibrillation (AF) increases thromboembolic risk, primarily stroke, due to stasis and abnormal atrial function. Antithrombotic therapy is central to AF management to prevent stroke and systemic embolism. Guidelines historically recommended vitamin K antagonists like warfarin, but the introduction of direct oral anticoagulants dabigatran, rivaroxaban, apixaban, edoxaban has shifted practice. These agents offer predictable pharmacokinetics and reduced need for monitoring. However, anticoagulation carries bleeding risk, particularly intracranial and gastrointestinal hemorrhage. Balancing ischemic prevention against bleeding risk remains a clinical challenge, guided by risk scores such as CHA₂DS₂-VASc for stroke and HAS-BLED for bleeding. Current guidelines from ESC, ACC/AHA, and AHA/ASA recommend oral anticoagulation for AF patients with CHA₂DS₂-VASc ≥2 in men and ≥3 in women. DOACs are preferred over warfarin in non-valvular AF due to comparable or superior efficacy and lower rates of intracranial hemorrhage. Meta-analyses show apixaban has the lowest bleeding risk among DOACs, while dabigatran 150 mg has higher gastrointestinal bleeding but lower stroke risk. Warfarin remains an option for mechanical valves and severe mitral stenosis. Bleeding risk assessment using HAS-BLED identifies modifiable factors like uncontrolled hypertension and concomitant antiplatelet use. Recent trials support low-dose DOACs in high bleeding risk patients, though efficacy may be reduced. Left atrial appendage closure is considered for patients with contraindications to anticoagulation. Real-world data confirm DOAC adherence improves outcomes, but renal function monitoring is essential to avoid accumulation and bleeding. Antithrombotic therapy in AF should be individualized based on stroke and bleeding risk. DOACs are first-line for most patients with non-valvular AF due to favorable safety profiles. Ongoing evaluation of bleeding risk and renal function is critical. Future research should refine risk stratification and explore safer anticoagulant strategies for high-risk populations. Guideline adherence improves outcomes, but clinical judgment remains essential in balancing efficacy and safety.