Troponin in critically ill patients

Assays of cardiac troponin have become a cornerstone in the diagnosis of myocardial infarction across a broad range of clinical settings. In critically ill patients, cardiac troponin is detectable in the plasma in up to 60% of cases, and this incidence may increase further as assays become more sensitive. Troponin rises in critical care are commonly unrelated to pathology in the coronary arteries, but are frequently associated with conditions such as sepsis and respiratory failure. Such non-coronary troponin release is a significant, independent predictor of poor patient outcomes, and can be incorporated into risk scoring systems. Despite adding prognostic value, treatment for non-coronary troponin rises remains limited to management of the underlying cause, and restoration of a favourable balance between myocardial oxygen demand and supply. Conversely, troponin rises secondary to myocardial infarctions are amenable to the same interventions as in any other setting, albeit with additional diagnostic and therapeutic challenges. In this review, we will explore the utility of troponin as a biomarker in critical care, and we will outline a pragmatic management strategy for this patient population.