Meta-analysis of the combination of warfarin and dual antiplatelet therapy after coronary stenting in patients with indications for chronic oral anticoagulation.

BACKGROUND: The optimal antithrombotic strategy for patients with chronic oral anticoagulation undergoing coronary stenting is unknown. Our study conducted a meta-analysis of 9 previous trials comparing the safety and efficacy of triple antithrombotic regimen (including warfarin, aspirin and clopidogrel) to non-triple antithrombotic regimens in those patients.
METHODS: Two investigators independently searched Pubmed, Ovid and Elsevier databases for all reported studies, and yielded 9 (of 242 potentially relevant) articles, published before July 2009, enrolling 5181 patients, follow-up period ranging from 1 month to 18 months. Two coauthors independently recorded the data regarding interventions and the occurrence of major bleeding, stroke, myocardial infarction and death.
RESULTS: Patients with triple antithrombotic regimen had significant reduction in ischemic stroke (odds ratio [OR] is 0.29, 95% confidence interval [CI] is from 0.15 to 0.58; and P=0.0004) as compared with dual antiplatelet therapy. While there was a two-fold increased risk of major bleeding associated with triple antithrombotic regime (OR 2.00, 95% CI 1.41 to 2.83; and P<0.0001). The overall incidence of death (OR 1.20, 95% CI 0.63 to 2.27, and P=0.56) and myocardial infarction (OR 0.84, 95% CI 0.57 to 1.23; and P=0.38) was comparable between the two regimens.
CONCLUSION: Our study confirmed the cardiovascular benefits of triple antithrombotic regimen by reducing ischemic stroke risk, but also demonstrated its increased risk of major bleeding. It poses imperative demands for future prospective randomized studies to define the optimal antithrombotic regimen in patients requiring chronic anticoagulation undergoing coronary stenting.