Serum cardiac troponin I is a candidate biomarker for cardiomyopathy in Duchenne and Becker muscular dystrophies.

Myocardial injury indicated by cTnI elevation was more common and severe in DMD patients. cTnI elevation preceding cardiac dysfunction may represent an early phase of cardiomyopathy progression and may be a biomarker for early detection of cardiomyopathy in these dystrophinopathies. The ACTN3 XX genotype may be a risk factor for early myocardial injury.