Elevated Cardiac Troponin T in Patients with Lupus Myositis Presenting with Noncardiac Chest Pain

Abstract

Patients with systemic lupus erythematosus (SLE) presenting with chest pain pose a unique diagnostic challenge, with causes ranging from cardiopulmonary disease to esophageal disorders and musculoskeletal chest wall pain. The most common biomarkers for myocardial injury are cardiac troponin T and I (cTnT and cTnI) due to their high sensitivity for the early detection of myocardial infarction. In the idiopathic inflammatory myopathies, cTnT is commonly elevated, and this reflects skeletal muscle breakdown rather than myocardial damage. Similar observations have not been reported in SLE myositis to date. We present two cases of patients with SLE and associated myositis who presented with chest pain and elevated cTnT. Both patients had a normal cTnI, transthoracic echocardiogram, and cardiac magnetic resonance imaging, likely indicating noncardiac chest pain. Clinicians should be aware that the specificity of cTnT might be lower in SLE myositis and that cTnI elevation may be more specific in detecting myocardial insult.

Using Cardiac Magnetic Resonance Imaging to Evaluate Patients with Chest Pain in the Emergency Department

“…Several examples of myocardial injuries with normal heart structure and tissue characterization on CMR are prolonged episodes of tachycardia, pulmonary embolism (often with right ventricular dysfunction), stroke (with and without ECG changes and/or LV dysfunction), strenuous exercise, and myositis (in particular, if hsTn assays are used). 20) However, troponin release in these situations might not represent true myocardial damage but rather release of cytosolic troponin or increased cell membrane permeability under stress. 12) In some clinical scenarios (e.g., motor vehicle accident with chest trauma and loss of consciousness or syncope during/after strenuous activity), CMR can be useful to exclude underlying structural heart disease as the cause for the inciting event and abnormal hsTn versus cardiac contusion and/or strenuous exercise alone.…”