WOEST Trial (2013): Clopidogrel with or without aspirin in patients taking OAC and undergoing PCI
WOEST Trial Summary
WOEST trial was an open-label randomized controlled trial in patients who were on oral anticoagulants and underwent PCI with coronary stenting. Patients who were on oral anticoagulants and underwent PCI with coronary artery stenting (N=573) were randomly assigned to 2 groups: Dual therapy (Clopidogrel and OAC) or triple therapy (Aspirin, clopidogrel, and OAC).
The primary outcome observed was any bleeding episode that occurred within 1 year of PCI. The secondary end point was a composite of death, myocardial infarction, stroke, target-vessel revascularization and stent thrombosis. The allocated antiplatelet treatment was continued for at least one month and up to 1 year for those patients who received a bare metal stent. For those who received a drug-eluting stent or had ACS clopidogrel was given for at least a year. The occurrence of any bleeding (primary endpoint) in the double therapy group was 19.4% as compared to triple therapy group which was 44.4%, with a HR of 0.36 (p <0.0001, 95% CI 0.26-0.50).
TIMI major and minor bleeding events occurred in 14% and 31.3% of the double and triple therapy groups respectively with a HR of 0.40 (p <0.0001, 95% CI 0.27-0.58). The composite secondary endpoint was observed in 11.1% and 17.6% of patients in the double and triple therapy groups respectively (HR 0.60, p =0.025, 95% CI 0.38-0.94). The WOEST trial investigators showed that the use of dual therapy reduced the risk of bleeding by the end of 1 year in patients who underwent PCI. An interesting finding in the study also showed that rates of thrombotic and thromboembolic events did not differ between the patients who did and did not receive aspirin.