Illustrations cliniques d’un manque de cardiospécificité du dosage de troponine T hypersensible

Introduction - Myositis are systemic diseases, in which heart damage is possible. Cardiac troponin T is often found to be defective to detect cardiac involvement. Observation - We report cases of two patients with a myositis. Diagnosis was retained based on muscle pain, increase in serum creatinine kinase, and inflammatory muscle damage on MRI. Histology confirmed the diagnosis for one of the two patients. Cardiac troponin T was measured in both patients, to detect myocardial involvement. Despite a serum elevation of this marker, cardiological assessment remained negative (electrocardiogram, cardiac ultrasound, cardiac MRI). Cardiac troponin I was normal in serum because of the absence of correlation with peripheral muscle involvement. Conclusion - Cardiac troponin T is correlated with muscle involvement in patients with myositis. Cardiac troponin I should be preferred because of a better specificity.