The role of clopidogrel and acetylsalicylic acid in the prevention of early-phase graft occlusion due to reactive thrombocytosis after coronary artery bypass operation.

BACKGROUND

Reactive thrombocytosis has been reported in 20% of patients after coronary artery bypass grafting (CABG), a frequency that might be related to the high incidence of thrombotic complications. The present study was planned to investigate the effect of combined treatment with clopidogrel and acetylsalicylic acid (ASA) on post-CABG reactive thrombocytosis.

METHODS

Included in this prospective, randomized study were 60 patients who underwent CABG operation with a 6-month follow-up. Three study groups were defined: group 1 (n = 20), a control group of patients who have not developed reactive thrombocytosis after CABG surgery; group 2 (n = 20), patients who have developed reactive thrombocytosis and continue taking ASA (300 mg/day); and group 3 (n = 20), patients who have developed reactive thrombocytosis and continue taking ASA (300 mg/day) with the addition of clopidogrel (75 mg/day).

RESULTS

The mean ages and sex distributions of the patient groups were similar. There were no significant differences between the groups regarding cardiovascular risk factors, baseline laboratory findings, or intraoperative characteristics. Thrombocytosis disappeared within the first month after the operation in both treatment groups. An evaluation of graft patency in the sixth postoperative month revealed that group 2 had significantly more patients with a "positive" result in the exercise test than group 3 and that group 3 had a lower incidence of graft occlusion than group 2 (P < .01).

CONCLUSIONS

Combination antiplatelet therapy with ASA and clopidogrel seems to be more effective than ASA alone for maintaining graft patency in patients with reactive thrombocytosis.