Relationship between Serum Total Cholesterol, Infarct Size, and Early Clinical Outcome following Acute Myocardial Infarction

Strategies designed to decrease coronary heart disease (CHD) associated morbidity and mortality have focused primarily on established risk factors, including hypercholesterolemia, systemic hypertension, and cigarette smoking. Indeed, primary and secondary intervention trials have provided evidence for cholesterol lowering as an efficient method of CHD risk reduction. To test the hypothesis that serum total cholesterol influences the clinical outcome following acute myocardial infarction, infarct size, left ventricular ejection fraction, infarct-related vessel patency, and in-hospital cardiac events were determined in 106 consecutive patients given thrombolytic therapy within 5 h of symptom onset. Cumulative 48-hour creatine kinase (CK) release, peak CK, and calculated infarct size did not differ significantly between patients with an admitting serum total cholesterol level less than 200 mg/dl (group 1) and those with a cholesterol level greater than 250 mg/dl (group 2). Total cholesterol did not correlate with either cumulative CK release, peak CK, infarct size, vessel patency, or left ventricular ejection fraction. The vessel patency correlated inversely with cumulative CK release (r = -0.27; p = 0.03) and directly with left ventricular ejection fraction (r = 0.24; p = 0.03). The incidence of in-hospital cardiac events including recurrent infarction, congestive heart failure, and death was 6.9, 13.9, and 2.6%, respectively, and did not differ significantly between patient groups. Thus, although serum total cholesterol has been shown to influence CHD incidence, morbidity, and overall mortality, the findings of our study suggest that it does not impact directly on infarct size, left ventricular function, or in-hospital clinical outcome among patients sustaining acute myocardial infarction.