Oral Anticoagulation and Antiplatelets in Atrial Fibrillation Patients After Myocardial Infarction and Coronary Intervention
What is the risk of thrombosis and bleeding according to multiple antithrombotic treatment regimens in atrial fibrillation (AF) patients after myocardial infarction (MI) or percutaneous coronary intervention (PCI)?
A total of 12,165 AF patients hospitalized with MI and/or undergoing PCI between 2001 and 2009, were identified by nationwide registries (60.7% males, mean age 75.6 years). Risk of MI/coronary death, ischemic stroke, and bleeding according to antithrombotic treatment regimen was estimated by Cox regression models.
Within 1 year, MI or coronary death, ischemic stroke, and bleeding events occurred in 2,255 (18.5%), 680 (5.6%), and 769 (6.3%) patients, respectively. Relative to triple therapy (oral anticoagulation [OAC] + aspirin + clopidogrel), no increased risk of recurrent coronary events was seen for OAC + clopidogrel (hazard ratio [HR], 0.69 [0.48-1.00]), OAC + aspirin (HR, 0.96 [0.77- 1.19]), or aspirin + clopidogrel (HR, 1.17 [0.96-1.42]), but aspirin + clopidogrel resulted in a higher risk of ischemic stroke (HR, 1.50 [1.03-2.20]). Also, OAC + aspirin and aspirin + clopidogrel were associated with a significant increased risk of all-cause death (HR, 1.52 [1.17-1.99] and 1.60 [1.25-2.05]). When compared to triple therapy, bleeding risk was nonsignificantly reduced for OAC + clopidogrel (HR, 0.78 [0.55-1.12]) and significantly reduced for OAC + aspirin and aspirin + clopidogrel.
The authors concluded that in real-life AF patients with indication for multiple antithrombotic drugs after MI/PCI, OAC + clopidogrel were equal or better on both benefit and safety outcomes compared to triple therapy.
The primary finding of this study is that in AF patients after MI/PCI, the combination of OAC + clopidogrel is comparable to the recommended triple therapy in respect to the prevention of thromboembolic outcomes of MI/coronary death and ischemic stroke, while the risk of bleeding was similar. Notably, the risk of all-cause mortality was similar between OAC + clopidogrel and triple therapy, but markedly increased for other therapies (i.e., OAC + aspirin and dual antiplatelet therapy). The overall results are consistent with the recently published WOEST study. Data from additional large randomized studies are needed to estimate overall risk versus benefit of the different therapies.
Keywords: Stroke, Platelet Aggregation Inhibitors, Warfarin, Atrial Fibrillation
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