Optimal Duration for Clopidogrel Suspension Prior to Coronary Artery Bypass Grafting

American College of Cardiology (ACC) guidelines suggest clopidogrel (Plavix) suspension for 5 days before non-emergent cardiac surgery (class IIa, level B). It puts the patients with recent angioplasty and ongoing ischemia at a higher risk of stent thrombosis. We sought to determine the bleeding risk in patients who stopped clopidogrel at 3 and less than 3 days before coronary artery bypass grafting (CABG) as compared to the usual 5 days prior to CABG.

A retrospective single center study was performed; and a total of 90 patients were included. Forty patients were not on clopidogrel but underwent CABG and hence were used as a control group (group 3). Fifty remaining patients were divided into three groups. Patients in whom clopidogrel was stopped 3 days or less before CABG were included in group 1 (n = 25); group 2 included patients who followed the standard ACC guidelines and clopidogrel was suspended 5 days before the CABG (n = 17); and finally patients who had stopped clopidogrel 4 days prior to surgery were included in group 4 (n = 8). This was compared to controls. Postoperative hemoglobin drop was analyzed between subgroups using IBM SPSS version 25.

The mean age of the included population was 69.9 years (46 - 88) with 65% of them being male and 35% female patients. The difference in the hemoglobin fall was compared amongst these groups using the one-way ANOVA. There were no outliers, as assessed by boxplot, the data were normally distributed for each group, as assessed by Shapiro-Wilk test (P > 0.05), and there was homogeneity of variances, as assessed by Levene's test of homogeneity of variances (P > 0.05). The fall in hemoglobin for the four different groups was analyzed. The fall in hemoglobin in group 1 (stopped clopidogrel 3 days or less before CABG) was (n = 25, 2.36 ± 1.24), the fall in group 2 (stopped clopidogrel 5 days prior to CABG) was (n = 17, 2.89 ± 1.22), the fall in hemoglobin in group 3 (patients not on clopidogrel) was (n = 40, 2.54 ± 1.35), and the fall in hemoglobin in group 4 (patients stopped clopidogrel 4 days prior to CABG) was (n = 8, 2.02 ± 1.31). ANOVA was subsequently performed on the patient data, which showed no statistical difference between all the four groups regarding the fall in hemoglobin during surgery (P = 0.41).

Our study concludes that there was no significant difference in the hemoglobin drop of the patients who had clopidogrel stopped 3 days prior to the major procedure like CABG in comparison to the patients who stopped clopidogrel 5 days before surgery. We advocate, that early cessation of clopidogrel is posing a threat of thrombosis in high risk patients with no additional benefit of decreased bleeding risks. However, large population studies are needed to validate the results.