Narrative review: Alternative causes for elevated cardiac troponin levels when acute coronary syndromes are excluded

Current guidelines for the diagnosis of non-ST-segment elevation myocardial infarction are largely based on an elevated troponin level. While this rapid and sensitive blood test is certainly valuable in the appropriate setting, its widespread use in a variety of clinical scenarios may lead to the detection of troponin elevation in the absence of thrombotic acute coronary syndromes. Many diseases, such as sepsis, hypovolemia, atrial fibrillation, congestive heart failure, pulmonary embolism, myocarditis, myocardial contusion, and renal failure, can be associated with an increase in troponin level. These elevations may arise from various causes other than thrombotic coronary artery occlusion. Given the lack of any supportive data at present, patients with nonthrombotic troponin elevation should not be treated with antithrombotic and antiplatelet agents. Rather, the underlying cause of the troponin elevation should be targeted. However, troponin elevation in the absence of thrombotic acute coronary syndromes still retains prognostic value. Thus, cardiac troponin elevations are common in numerous disease states and do not necessarily indicate the presence of a thrombotic acute coronary syndrome. While troponin is a sensitive biomarker to "rule out" non-ST-segment elevation myocardial infarction, it is less useful to "rule in" this event because it may lack specificity for acute coronary syndromes.