Prevalence and impact of metabolic syndrome on hospital outcomes in acute myocardial infarction

BACKGROUND: The impact of metabolic syndrome after acute myocardial infarction (AMI) has not yet been studied. In a population-based sample of patients with AMI, we sought to determine the prevalence of metabolic syndrome in patients with AMI, its impact on hospital outcomes, and to assess the relative influence of each of the components of the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III definition of metabolic syndrome on the risk of death and heart failure. METHODS: A total of 633 unselected, consecutive patients hospitalized with AMI were categorized according to the NCEP ATP III metabolic syndrome criteria (presence of >/=3 of the following: hyperglycemia; triglyceride level >/=150 mg/dL [>/=1.7 mmol/L]; high-density lipoprotein cholesterol level <40 mg/dL [<1.04 mmol/L] in men and <50 mg/dL [<1.30 mmol/L] in women; blood pressure >/=130/85 mm Hg; and waist circumference >102 cm in men or 88 cm in women). RESULTS: Among the 633 patients, 290 (46%) fulfilled the criteria for metabolic syndrome. Patients with metabolic syndrome were older and more likely to be women. Acute myocardial infarction characteristics and left ventricular ejection fraction rates were similar for both groups. In-hospital case fatality was higher in patients with metabolic syndrome compared with those without, as was the incidence of severe heart failure (Killip class >II). In multivariate analysis, metabolic syndrome was a strong and independent predictor of severe heart failure, but not in-hospital death. Analysis of the predictive value of each of the 5 metabolic syndrome components for severe heart failure showed that hyperglycemia was the major determinant (odds ratio, 3.31; 95% confidence interval, 1.86-5.87). CONCLUSIONS: In an unselected population of patients with AMI, the prevalence of metabolic syndrome was high. Metabolic syndrome appeared associated with worse in-hospital outcome, with a higher risk of development of severe heart failure. Among metabolic syndrome components, hyperglycemia was the main correlate of the risk of development of severe heart failure during AMI.