Use of Clopidogrel With or Without Aspirin in Patients Taking Oral Anticoagulant Therapy and Undergoing Percutaneous Coronary Intervention: An Open-Label, Randomised, Controlled Trial

Study Questions:

What is the safety and efficacy of clopidogrel alone compared with clopidogrel plus aspirin in patients requiring oral anticoagulant therapy after percutaneous coronary intervention (PCI)?


The WOEST (What is the Optimal antiplatElet and anticoagulant therapy in patients with oral anticoagulation and coronary StenTing) authors performed an open-label, randomized, controlled trial in 15 centers in Belgium and the Netherlands. A total of 573 patients receiving oral anticoagulants and undergoing PCI were assigned clopidogrel alone (double therapy) or clopidogrel plus aspirin (triple therapy). The primary outcome was any bleeding episode within 1 year of PCI, assessed by intention to treat.


Indication for anticoagulation was atrial fibrillation in 69% of the patients. Outcome data at 1 year were available for 279 (98.2%) patients assigned to the double-therapy arm and 284 (98.3%) assigned to the triple-therapy arm. A significant reduction in bleeding was seen with double therapy (19.4% vs. 44.4%, hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.26-0.50; p < 0.0001). In the double-therapy group, six (2.2%) patients had multiple bleeding events, compared with 34 (12.0%) in the triple-therapy group. Blood transfusion was required for 11 (3.9%) patients receiving double therapy compared with 27 (9.5%) patients in the triple-therapy group (odds ratio, 0.39; 95% CI, 0.17-0.84; p = 0.011). The combined secondary endpoint of death, myocardial infarction, stroke, target-vessel revascularization, and stent thrombosis was reported in 31 (11.1%) patients in the double-therapy group and in 50 (17.6%) in the triple-therapy group (adjusted HR, 0.56; 95% CI, 0.35-0.91). All-cause mortality at 1 year was 2.5% in the double-therapy group and 6.3% in the triple-therapy group.


Use of clopidogrel without aspirin was associated with a significant reduction in bleeding complications and no increase in the rate of thrombotic events in patients who required oral anticoagulant therapy after PCI.


Multiple studies have demonstrated a very high risk of bleeding among patients who require triple therapy after PCI and have a very high risk of bleeding. This innovative study demonstrates the safety of using oral anticoagulants and clopidogrel and foregoing the use of aspirin in this population. The reduction in bleeding without an increase in thrombotic events suggests that this may be the optimal regimen for patients who require oral anticoagulation after PCI. The study was underpowered to detect a difference in ischemic events, and larger studies are needed to establish the safety of this approach before the results of this study can be routinely applied to clinical practice.

Keywords: Blood Transfusion, Myocardial Infarction, Belgium, Netherlands, Angioplasty, Balloon, Coronary, Stents, Percutaneous Coronary Intervention

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