Hypercoagulability and platelet inhibition after OPCAB. Randomized intervention with clopidogrel.

Objective. Data on graft patency after Off-Pump Coronary Artery Bypass (OPCAB) suggest that the incidence of early graft closure is not increased compared to conventional coronary artery bypass surgery. However, hypercoagulability following OPCAB is still of concern, and acetylsalicylic acid as thromboembolic prophylaxis might be insufficient in the first weeks following OPCAB surgery. Design. Twenty nine patients were randomly assigned to+/− 75 mg of clopidogrel until 30 days after OPCAB surgery. The follow-up time was 2 months including standard blood samples and thrombelastography (TEG) with a specific platelet inhibition assay, which was evaluated as a part of the study. Results. In both groups a significant increase in TEG maximum amplitude was found 5 days after surgery. Platelet inhibition showed great variations but was significantly increased in the clopidogrel group (34.1%) vs. control group (11.0%) after 1 month. Conclusion. Hypercoagulability was seen 5 days after OPCAB and could not be demons...