Clearance of a 3H-labeled chylomicron-like emulsion following the acute phase of myocardial infarction

Abstract Background : Plasma lipids may be altered during acute myocardial infarction and may not reflect patient baseline lipid profile. The metabolism of chylomicrons, the lipoproteins that carry the dietary lipids in the bloodstream has not yet been studied in acute myocardial infarction patients. Methods : In this study, a lipidic emulsion that mimics the intravascular behavior of chylomicrons labeled with cholesteryl oleate ( 3 H-CO) was injected intravenously in 17 normolipidemic patients on the seventh and on the 45th day post-non complicated acute myocardial infarction after a 12-h fast. The plasma decay curve of the emulsion label was determined from blood samples collected during 60 min. Data were also compared with a group of 10 patients with chronic coronary artery disease. Results : In the acute myocardial infarction group, the plasma fractional catabolic rates of the emulsion 3 H-CO, expressed as median and confidence intervals, did not change from the seventh to the 45th day after the acute event [0.0773 (0.061, 0.1025) min −1 vs. 0.0672 (0.00507, 0.1009) min −1 P =0.61] and was similar to that determined in chronic coronary artery disease patients. High-density lipoprotein cholesterol and apolipoprotein AI were lower on the seventh day when compared to the 45th day post acute myocardial infarction ( P =0.01 and P =0.004, respectively). No changes were found in LDL and total cholesterol as well as in plasma triglycerides in myocardial infarction group. Conclusions : No changes were found in chylomicron metabolism is in the acute phase of myocardial infarction.