Elevated cardiac troponin is an independent risk factor for short- and long-term mortality in medical intensive care unit patients

Background. Troponin elevations are common in critically ill patients. Whether they are predictors of mortality independent of the severity of the underlying disease is unclear. Objective: To determine whether troponin elevations predict in-hospital, short-term, and long-term mortality in medical intensive care unit patients independent of the severity of the underlying disease as measured by Acute Physiology and Chronic Health Evaluation III prognostic system. Design: Retrospective study. Setting: We examined the Acute Physiology and Chronic Health Evaluation III database and cardiac troponin T levels of medical intensive card unit patients at Mayo Clinic, Rochester, MN. Patients: In all, 1,657 patients consecutively admitted to medical intensive care units between August 2000 and December 2001. Measurements: In-hospital, short-term (30-day), and long-term all-cause mortality. Results, During hospitalization, 12.5% of patients with a cardiac troponin T < 0.01 mu g/L suffered deaths compared with 29.5% among those with cardiac troponin T >= 0.01 mu g/L (p <.001). At 30 days, mortality was 13.7% without and 34.6% with elevations (p <.001). The expected probability of survival at 1-, 2-, and 3-yr follow-up was 43.7%, 33.8%, and 25.7% among patients with cardiac troponin T >= 0.01 mu g/L and 75.3%, 67.6%, and 62.9% in those with cardiac troponin T < 0.01 mu g/L, respectively (p <.001). After adjustment for the severity of disease and baseline characteristics, cardiac troponin levels were still associated with in-hospital, short-term, and long-term mortality (p = 006, p =.007, and p =.001, respectively). Limitations. This is a single-site retrospective study that included only patients in whom a troponin level was obtained on admission. Conclusions. In medical intensive care unit patients, admission troponin levels Are independently associated with short- and long-term mortality, even after adjustment for severity of disease.