Long-term prognostic importance of total cholesterol in elderly survivors of an acute myocardial infarction: the Cooperative Cardiovascular Pilot Project

Abstract

OBJECTIVES: To determine the long-term prognostic importance of in-hospital total serum cholesterol in elderly survivors of acute myocardial infarction (AMI). DESIGN: Retrospective medical record review. SETTING: Acute care, nongovernmental hospitals in Alabama, Connecticut, Iowa, and Wisconsin. PARTICIPANTS: Four thousand nine hundred twenty-three Medicare beneficiaries from four states aged 65 and older discharged alive with a principal diagnosis of AMI between June 1, 1992, and February 28, 1993, who had a measurement of total serum cholesterol during hospitalization. MEASUREMENTS: Primary endpoint of all-cause mortality within 6 years of discharge. RESULTS: Of the 7,166 hospitalizations meeting study inclusion criteria, 4,923 (68.7%) had total cholesterol assessed, and 22% had a cholesterol level of 240 mg/dL or greater. Of AMI hospitalization survivors with cholesterol of 240 md/dL or greater, 17.2% died within 1 year and 47.9% died within 6 years, compared with 17.4% (P =.73) and 48.7% (P =.98) of those with a cholesterol level less than 240 mg/dL. The adjusted hazard ratio for elevated total serum cholesterol measured during hospitalization for all-cause mortality in the 6 years after discharge was 0.97 (95% confidence interval (CI) = 0.87-1.09). The unadjusted 1- and 6-year mortality rates for those with total cholesterol less than 160 mg/dL were 22.2% and 55.5%, respectively, not significantly different from mortality for patients with cholesterol of 160 mg/dL or greater, even after adjustment. CONCLUSION: Among elderly survivors of AMI, elevated total serum cholesterol measured postinfarction is not associated with an increased risk of all-cause mortality in the 6 years after discharge. Furthermore, this study found no evidence of an increased risk of all-cause mortality in patients with low total cholesterol. Further studies are needed to determine the relationship of postinfarction lipid subfractions and mortality in older patients with coronary artery disease (CAD).