Elevated troponin in non-cardiac critical illness---what does it mean?

This is a controversial situation that comes up frequently in the ICU, especially in patients with sepsis. It was the subject of a prospective study published September 28 in Critical Care. Earlier literature has suggested that elevated troponin in the setting of sepsis is associated with left ventricular dysfunction [1] [2] [3] [4] [5] and mortality [2] [6] [3] [4] [5]. These same studies demonstrate elevated troponin in close to half of sepsis patients.

In keeping with previous reports, the Critical Care paper found troponin elevation in almost half of their population of ICU patients. About half of those with elevated troponin were found to meet previously defined criteria for myocardial infarction. The new finding in this study was that among patients with elevated troponin only those meeting criteria for myocardial infarction had a worse outcome. Troponin elevation absent other criteria for MI was not associated with a worse prognosis.

Although the mechanism of elevated troponin is non-cardiac critical illness remains uncertain this study adds significantly to our understanding of the problem.