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Background: Aspirin used after coronary artery bypass graft surgery (CABG) improved patient survival and reduced graft
thrombosis. However, individual variations in the antiplatelet effect of aspirin have been reported among CABG patients.
Objective: To compare the intensity of platelet aggregation between patients receiving low and high aspirin dosage in post
Methods: We prospectively studied the effect of aspirin dosage on platelet aggregation in 100 CABG patients. Oral aspirin
was discontinued prior to CABG and re-started within 12 hours after CABG. Blood samples were collected and transferred
to a laboratory prior to surgery then again on postoperative days two and eight for platelet aggregation test and platelet count
within three hours after venipuncture.
Results: One hundred patients (sixty five male and thirty five female patients) post coronary artery bypass graft (CABG) were
evaluated for eligibility to enter the trial. The percentage of platelet aggregation was compared between low dose (<100 mg/
day), and high dose (>100 mg/day) aspirin, at postoperative CABG days 2 and 8, which showed no significant difference for
the platelet aggregation (p = 0.161 post CABG day 2 and p = 0.098 post CABG day 8).
Conclusion: Low dosage aspirin should be used in post CABG patients because the intensity of platelet aggregation between
patients post CABG receiving low and high aspirin dosage were not different, while the prophylactic effect of the low aspirin
dosage in reducing the risk of cardiovascular events proved equally as effective as the high aspirin dosage.
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