Changes in cholesterol levels after coronary artery bypass surgery.
To determine the factors responsible for the dramatic fall in cholesterol levels after coronary artery bypass surgery (CABG), the authors reviewed, in a retrospective study, the cholesterol levels of 36 patients who underwent CABG surgery during 1987 and compared their levels with those of a control group of 30 patients who underwent cholecystectomies during the same time. In a prospective study, the authors measured the lipids and the hematocrit levels of 15 patients undergoing CABG surgery before the initiation of cardiopulmonary bypass, after 5 minutes of extracorporeal circulation (ECC), and at the end of ECC. In the CABG group, the plasma cholesterol level fell from 211 +/- 63 mg/dl (mean +/- SE) to 70 +/- 48 mg/dl (p less than 0.01), a 77% decrease within 24 hours of surgery. In the cholecystectomy group, the plasma cholesterol fell from 192.3 +/- 8.9 mg/dl to 158 +/- 76 mg/dl (p less than 0.01), an 18% decrease within 24 hours of surgery. To estimate the contribution of hemodilution or blood loss to the fall in cholesterol, changes in hematocrit were recorded. In the CABG group, hematocrit fell from 39.5 +/- 0.7% to 23.5 +/- 0.7% 24 hours after surgery (41% decrease) (p less than 0.01), whereas in the cholecystectomy group hematocrit fell from 39.4 +/- 0.8% to 37.1 +/- 0.9% on the first postoperative day (6% decrease). There was a positive correlation between the fall in cholesterol and the fall in hematocrit in the CABG group (correlation coefficient 0.472), suggesting that hemodilution was a major factor in the decrease in cholesterol levels.(ABSTRACT TRUNCATED AT 250 WORDS)
Figueroa
O
O
Department of Medicine, Medical College of Ohio, Toledo 43699.
Franco-Saenz
R
R
Mulrow
P J
PJ
Montesinos
E
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002784:Cholesterol / Q000097:blood*; D001026:Coronary Artery Bypass; D005112:Extracorporeal Circulation; D005260:Female; D006400:Hematocrit; D006438:Hemodilution; D006801:Humans; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood
D008074:Lipoproteins; D014280:Triglycerides; D002784:Cholesterol