ObjectiveTo investigate the influence of different discontinuation time of clopidogrel and aspirin before off-pump coronary artery bypass grafting on postoperative volume of drainage and blood products imported.MethodsA total of 454 patients who underwent coronary artery bypass grafting in Beijing Anzhen Hospital from January 2017 through December 2019 were included. According to the preoperative discontinuation of clopidogrel and aspirin, all the 454 patients were divided into three groups including a guide group, a non-stop group and a stop group. There were 86 patients in the guide group including 59 males and 27 females with an average age of 64.12±6.15 years. They continued to take aspirin 100 mg/d before operation, but stopped clopidogrel for more than 5 days. In the non-stop group, there were 234 patients including 141 males and 93 females with an average age of 63.71±7.01 years. They continued to take aspirin 100 mg/d before operation, and stopped clopidogrel <5 days. In the stop group, there were 134 patients including 76 males and 58 females with an average age of 62.90±7.78 years. They stopped aspirin and clopidogrel for more than 5 days before operation. The clinical effectiveness was compared among the three groups.ResultsNo perioperative death occurred in all patients. There was no statistical difference in platelet count, coagulation function, liver function, renal function, or myocardial markers among the groups (P>0.05). The hemoglobin [97 (15) g/ L vs. 98 (21) g/L vs. 100 (20) g/ L, F=4.894, P=0.008] in the non-stop group was lower than that in the guide group and the non-stop group at 30 minutes postoperatively. The flow volume (399.87±127.19 mL vs. 367.05±125.89 mL vs. 349.63±130.68 mL, F=7.770, P=0.000) in the non-stop group at 3 hours postoperatively, the flow volume [600 (300) mL vs. 580 (245) mL vs. 550 (350) mL, Z=8.218, P=0.016] in the non-stop group at 6 hours postoperatively, the flow volume [750 (370) mL vs. 730 (350) mL vs. 730 (350) mL, Z=8.329, P=0.016] in the non-stop group at 12 hours postoperatively, the flow volume [890 (365) mL vs. 850 (340) mL vs. 850 (350) mL vs. Z=6.585, P=0.037] in the non-stop group at 24 hours postoperatively and the flow volume [950 (375) mL vs. 940 (360) mL vs. 940 (380) mL, Z=8.680, P=0.013] in the non-stop group at 48 hours postoperatively were more than those of the guide group and the stop group. The retention time of drainage tube was longer in the non-stop group [3 (1) d vs. 3 (1) d vs. 3 (1) d, Z=6.579, P=0.037] than in the guide group and the non-stop group. The amount of suspended erythrocytes input [0 (2) U vs. 0 (2) U vs. 0 (0) U, Z=6.150, P=0.046], and the amount of plasma input [200 (200) mL vs. 0 (200) mL vs. 0 (200) mL, F=4.144, P=0.016], the number of cases of plasma input (119 patients vs. 34 patients vs. 47 patients, Z=10.116, P=0.006) were more than those of the guide group and the stop group.ConclusionAspirin maintenance is recommended for patients before off-pump coronary artery bypass grafting. If not necessary, clopidogrel is discontinued for at least 5 days.