Effect of cardiopulmonary bypass versus off-pump coronary artery bupass grafting on platelet inhibition rate and Aspirin resistance after coronary artery bypass grafting surgery

Abstract

Objective To investigate the effect of cardiopulmonary bypass(CPB)on platelet inhibition rate(INHAA)and Aspirin resistance(AR)after coronary artery bypass grafting(CABG)surgery. Methods A total of 114 patients undergoing CABG surgery were divided into two groups: on-pump group(n=54)and off-pump group(n=60). Aspirin treatment(100 mg/d)was paused 7 days before surgery and continued 6 hours after surgery.INHAA was detected and calculated by using thrombelastography(TEG)at 6 hours after taking the last dose of aspirin before surgery(T0), 12 hours(T1), 5 days(T2), 10 days(T3)and 15 days(T4)after surgery respectively.The incidence of AR was calculated. Results There was no significant difference in the overall INHAA between the two groups of on vs.off-pump(F=0.336, P=0.563), while the differences of INHAA index at each time point was statistically significant between two groups of on vs.off-pump(F=95.519, P=0.000). There was an interaction effect of timing and grouping(F=15.500, P=0.000). In comparison of INHAA between the two groups of on vs.off-pump at each time point, INHAA was higher in on-pump group than in off-pump group at T1(P 0.05). In the on-pump group, the total difference of INHAA at different time points was significant(P 0.05). In comparison of AR incidence after CABG surgery between two groups of on vs.off-pump at each time point, the incidence of AR was lower in on-pump group than in off-pump group at T1(P 0.05). Conclusions The increase of platelet inhibition rate and aspirin resistance occurs in early period after CABG surgery.The platelet inhibition rate is higher and aspirin resistance rate is lower in on-pump group than in off-pump group at 12 h after surgery, and the platelet inhibition rate is lower at 5 days after CABG surgery in on-pump group than in off-pump group.CPB has little effect on the platelet inhibition rate and on the incidence of AR after 5 days of CABG surgery. Key words: Coronary artery disease; Extracorporeal circulation; Platelet aggregation inhibitors