From the Guidelines
For atrial fibrillation, anticoagulants are the preferred treatment, and if an antiplatelet must be used, aspirin 81-325 mg daily is the antiplatelet of choice, but it provides significantly less stroke protection than anticoagulation. The most recent and highest quality study, the 2024 ESC guidelines for the management of atrial fibrillation 1, recommends against antiplatelet therapy alone for stroke prevention in atrial fibrillation. The guidelines state that antiplatelet drugs, such as aspirin and clopidogrel, are not an alternative to oral anticoagulation (OAC) and should not be used for stroke prevention.
The reason anticoagulants are preferred is that atrial fibrillation creates stasis of blood in the left atrial appendage, leading to thrombus formation through the coagulation cascade rather than platelet aggregation. Anticoagulants directly target this mechanism, reducing stroke risk by approximately 65-70%, while aspirin only reduces stroke risk by about 20% 1. The AVERROES trial demonstrated a lower rate of stroke or systemic embolism with apixaban compared with aspirin (HR, 0.45; 95% CI, 0.32–0.62; P < .001) 1.
Key points to consider when managing atrial fibrillation include:
- Assessing stroke risk using the CHA₂DS₂-VASc score to determine if anticoagulation is indicated
- Preferably using direct oral anticoagulants (DOACs) such as apixaban, rivaroxaban, dabigatran, or edoxaban over warfarin for most patients
- Avoiding the combination of antiplatelet drugs with anticoagulants unless there is a clear indication, such as acute vascular disease
- Considering the patient's individual preferences, cost, and anticipated medication adherence when selecting an anticoagulant 1.
Overall, the current evidence supports the use of anticoagulants as the primary treatment for atrial fibrillation, with aspirin being used only in cases where anticoagulants are contraindicated or not tolerated.
From the Research
Antiplatelet Therapy for Atrial Fibrillation
- The use of antiplatelet therapy, such as aspirin, for stroke prevention in patients with atrial fibrillation is limited and associated with a similar risk of hemorrhagic events compared with anticoagulants 2.
- Antiplatelet drugs, including aspirin and clopidogrel, are inferior to oral anticoagulation (OAC) for stroke prevention in atrial fibrillation patients, with a comparable risk of bleeding events 3.
- Dual antiplatelet therapy as an alternative to oral anticoagulation requires further study, and its benefits and risks are not well defined 2, 4.
Comparison with Anticoagulation Therapy
- Oral anticoagulants, such as warfarin, dabigatran, apixaban, and rivaroxaban, are more effective than antiplatelet agents at reducing the risk of ischemic stroke and all strokes in atrial fibrillation patients 5.
- Direct oral anticoagulants (DOACs) have demonstrated a dramatic reduction in the rate of intracranial hemorrhage compared to warfarin, and offer the advantages of not requiring monitoring 6.
- The choice of anticoagulant therapy should be based on individual patient risk factors, including stroke and bleeding risk profile 5, 6.
Current Guidelines and Recommendations
- Current guidelines conflict on the use of antiplatelet monotherapy for stroke prevention in atrial fibrillation patients, with European guidelines not recommending it irrespective of stroke risk 2.
- The American guidelines recommend oral anticoagulation for patients with atrial fibrillation and a CHA2DS2-VASc score of greater than 1, beyond sex 2.