Serum Cholesterol Levels in Acute Myocardial Infarction and the Effect of Streptokinase on Cholesterol

It is well known that hypercholesterolemia is a major risk factor for coronary heart disease and lowering serum cholesterol levels decreases the morbidity and mortality of coronary heart disease. Serum cholesterol measurements and determining the time to start lipid lowering treatment after acute myocardial infarction stili remain controversial, though the effect of cholesterol on atherosclerosis is very well known. Our study is designated to investigate the progress of serum cholesterol levels before and after thrombolytic therapy and effect of streptokinase on cholesterol levels in acute myocardial infarction. One hundred and four patients, accepted to our coronary care unit, with acute myocardial infarction, the diagnosis based on pain, ECG and enzyme criteria, were included in the study. Blood was withdrawn on admission, for CK, CK-MB and serum lipid levels. Seventy-two of the participating patients received streptokinase. Serum lipid level studies were repeated on the 10th day and first and third month of infarction. The mean age of the patients was 56.2± 10.4. In-hospital mortality rate was %7.7, and no out-of-hospital death was recorded. There was no significant difference between serum lipid levels and control measurements in patients who received streptokinase and in patients, who had not (p>0.05). Serum total cholesterol, HDL and LDL cholesterol levels have decreased after myocardial infarction and reached to their initial levels at the end of the third month (r=0.52 p=0.0001; r=0.58 p=0.0001; r=0.59 p=0.0001), respectively. A weak correlation was obtained between peak CK-MB and serum total cholesterol levels (r=0.23 , p=0.04). We may conclude that streptokinase has no effect on serum lipid levels and the serum lipid levels on the first day and first month of infarction are close to each other, but are lower than the initial values on the first month, being most prominent on the 10th day of infarction. Lipid levels obtained on the first day, reflect the actual lipid profile and we recommend to perform the measurements on the first day of infarction and start the lipid lowering therapy, if needed, as soon as possible.