Etiology of troponin elevation in critically ill patients

PURPOSE: The aim of this study was to assess the etiology of cardiac troponin elevation among patients admitted to the intensive care unit (ICU) and to examine whether etiology affects mortality and length of stay. METHODS: All patients admitted over 2 months underwent screening with troponin measurements and were included if 1 or more measurements were elevated. Two adjudicators retrospectively reviewed patient charts to determine the likely cause of troponin elevation. RESULTS: Of 103 patient admissions, 52 (50.5%) had 1 or more elevated troponin measurements, and 49 (94.2%) had medical charts available for review. Troponin elevation was adjudicated as myocardial infarction (MI) in 53.1% of patients, sepsis in 18.4%, renal failure in 12.2%, and other causes in 16.3%. Overall ICU mortality was 16.0%; 2.0% for patients with no troponin elevation, 23.1% in patients with MI, and 39.1% in patients with troponin elevation not due to MI. Having an elevated troponin level not due to MI was significantly associated with increased hospital mortality compared with having no troponin elevation. CONCLUSIONS: The most common cause of troponin elevation among critically ill patients was MI. Patients with elevated troponin had worse outcomes compared with patients without troponin elevation, and troponin elevation not due to MI was predictive of increased hospital mortality.