A STUDY OF LIPID PROFILE BEFORE AND AFTER CORONARY-ARTERY BYPASS-GRAFTING

This study was undertaken to establish the variability in the levels o f total cholesterol (TC), total triglyceride (TG), low-density lipopro tein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol before and after coronary artery bypass graft (CABG) surgery, in orde r to determine postoperatively when an accurate assessment can be made of the lipid status. During a prospective study over 4 months, fastin g venous samples were taken pre- and postoperatively on day 5, and in the 4th, 8th and 12th weeks. Ninety-six patients admitted to the cardi othoracic and cardiac wards for CABG were recruited to the study. The mean preoperative levels were: TC 5.94 (+/- 0.1 mmol/l), LDL cholester ol 4.02 (+/- 0.05mmol/l) and HDL cholesterol 1.00 (+/- 0.03mmol/l). Th ese were significantly different (p<0.01) from the levels on the 5th p ostoperative day when the mean level of TC was 4.14 (+/- 0.084mmol/l), LDD cholesterol was 2.45 (+/- 0.07mmol/l) and HDL cholesterol was 0.7 4 (+/- 0.03mmol/l). By the 4th postoperative week, mean TC (5.73 +/- 0 .13mmol/l), LDL cholesterol (3.79 +/- 0.14mmol/l) and HDL cholesterol (1.03 +/- 0.04mmol/l) did not vary significantly from the mean preoper ative values. There was no significant difference in the mean TG level s pre- and postoperatively. The mean TC, LDL cholesterol and HDL chole sterol rise to preoperative levels by the 4th week after CABG. Thus, a n accurate assessment of patients' lipid status can be made from this period. An earlier postoperative assessment may be falsely reassuring.