Background: The current standard of care is to delay coronary surgery 5-7 days after clopidogrel exposure to prevent bleeding complications. We sought to determine the utility of an objective tool (ie, the VerifyNow assay) to measure platelet inhibition (PI) in patients receiving preoperative clopidogrel prior to off-pump coronary artery bypass grafting surgery (OPCABG).
Patients and methods: Between June 2007 and July 2009, a total of 482 isolated OPCABG procedures were performed at our institution. In 160 patients, the VerifyNow assay results were used to determine timing of the OPCABG. These patients were compared to the remaining 322 patients. We divided the cohort into 4 subgroups: Group 1 patients (n = 205) were not taking clopidogrel; Group 2 patients (n = 117) were taking clopidogrel, but the test was not performed; Group 3 patients (n = 122) were taking clopidogrel and had a preoperative PI result of ≤20%; and Group 4 patients (n = 38) had ≥21% preoperative PI.
Results: Demographic and clinical factors were compared in all groups. The median waiting time for surgery from the last dose of clopidogrel was 6 days for the control groups and 3 days for the groups where the test was performed (P<.001). Reoperation for bleeding occurred most often in Group 4 (7.9%; P=.003). Blood utilization was lower in Group 1 (24.4%) than in Groups 2 (34.2%), 3 (40.2%), or 4 (55.3%) (P<.001). Major complications and postoperative length of stay were similar in all groups.
Conclusions: Utilization of a PI tool in the preoperative assessment of OPCABG patients exposed to clopidogrel can provide valuable information to guide the timing of coronary surgery and may lead to a decrease in reoperation for bleeding and blood usage.