SERUM-CHOLESTEROL CONCENTRATION BEFORE AND AFTER STREPTOKINASE IN ACUTE MYOCARDIAL-INFARCTION

Objective. To determine if serum cholesterol concentration should be measured before or after streptokinase therapy within the first 24 h of myocardial infarction. Design. Prospective study of patients receiving streptokinase therapy for acute myocardial infarction (AMI). Setting. Coronary care unit of a district general hospital. Subjects. Thirty-one patients (26 men aged 38-74 years, mean 60 years) admitted with a definite diagnosis of myocardial infarction. Intervention. Streptokinase therapy given intravenously at a mean of 5 h (range 1.5-15 h) after the onset of chest pain. Main outcome measures. Serum cholesterol concentration just prior to, and 11.5 h (range 4-20.5 h) after streptokinase administration. Results. There was a significant mean fall of 0.4 mmol l(-1) (P=0.002, 95% CI=0.2-0.6) in serum cholesterol concentration from a prestreptokinase concentration of 7.0 (range 5.3-9.9) to a post-streptokinase concentration of 6.6 (range 4.9-9.9). In the patients who showed a fall in cholesterol concentration, the magnitude of fall correlated with the baseline cholesterol concentration (r = 0.66, P < 0.01) but not with peak cardiac enzyme activities (r = 0.05, P > 0.2 for aspartate aminotransferase; r = 0.10, P > 0.2 for lactate dehydrogenase), time from onset of chest pain to poststreptokinase measurement (r = 0.27, P > 0.2) or time from streptokinase administration to poststreptokinase measurement (r = 0.01, P > 0.2). Conclusion. Serum cholesterol concentration may be underestimated when measured after streptokinase therapy, particularly when the true basal value is high. Further management of this risk factor may be based more accurately on its measurement before than after streptokinase therapy within the first 24 h of AMI.