The effect of clopidogrel in combination with aspirin when given before coronary artery bypass grafting

Objectives This study was designed to evaluate the effect of preoperative clopidogrel on coronary artery bypass graft surgery (CABG) outcomes. Background Clopidogrel in combination with aspirin, given before percutaneous coronary intervention, has become the standard for stent thrombosis prevention. Some premedicated patients, however, are found to have surgical disease on angiography, and irreversible platelet inhibition becomes a concern for upcoming CABG. Methods We prospectively studied 224 consecutive patients undergoing nonemergent first-time CABG, and compared those with preoperative clopidogrel exposure within seven days (n=59) to those without exposure (n=165). Results The groups were comparable in age, gender, body surface area, preoperative hematocrit, preoperative prothrombin time and prior myocardial infarction. The clopidogrel group had higher 24-h mean chest tube output (1,224 ml vs. 840 ml, p=0.001), and more transfusions of red blood cells (2.51 U vs. 1.74 U, p=0.036), platelets (0.86 U vs. 0.24 U, p=0.001) and fresh frozen plasma (0.68 U vs. 0.24 U, p=0.015). Moreover, reoperation for bleeding was 10-fold higher in the clopidogrel group (6.9% vs. 0.6%, p=0.018). The clopidogrel group also had less extubation within 8 h (54.2% vs. 75.8%, p=0.002) and a trend towards less hospital discharge within five days (33.9% vs. 46.7%, p=0.094). Conclusions Clopidogrel in combination with aspirin before CABG is associated with higher postoperative bleeding and morbidity. These findings raise concern regarding the routine administration of clopidogrel before anticipated coronary stent implantation.