Moderately elevated serum troponin concentrations are associated with increased morbidity and mortality rates in surgical intensive care unit patients

OBJECTIVE: To determine the significance of moderate elevations of serum troponin I in a surgical intensive care unit patient population in terms of its impact on indexes of outcome including mortality, morbidity, and hospital and intensive care unit length of stay. DESIGN: Retrospective chart review and analysis of clinical data. SETTING: A surgical intensive care unit at a tertiary care hospital. PATIENTS: From the 27-month surgical intensive care unit database of admissions, 869 patients with serum troponin I determinations during their admission were identified. Patients who had cardiac surgery were excluded. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Patients were divided into four groups based on their maximum serum troponin I concentrations. Hospital mortality, incidence of myocardial infarction, and hospital and intensive care unit length of stays were compared. Patients with moderate elevations of serum troponin I (0.4-2.0 microg/L) had a significantly higher mortality rate (chi-square = 32.57, p or =2 microg/L. CONCLUSION: Moderate elevations of serum troponin I, which are below the threshold required to diagnose overt myocardial infarction, may reflect ongoing myocardial injury in the critically ill and are associated with a higher mortality rate and longer hospital and intensive care unit length of stays. The use of beta-blockers and aspirin is associated with better outcomes for this subset of patients.