Early identification of rapid progressive myocardial injury in Duchenne muscular dystrophy: a prospective, single-center cohort study

Background Episodes of acute heart failure and sudden death are always reported in Duchenne muscular dystrophy. However, the development process of secretive myocardial injury before malignant events in DMD is not easy to identify in the early stage, and the process of its occurrence and development is also not very clear. In this study, we aim to clarify the different development processes of myocardial injury and its significance in DMD, and optimize the long-term management of DMD-associated cardiomyopathy. Methods A prospective, single-center cohort study of DMD children was conducted between June 2023 and April 2025 at West China Second University Hospital. Clinical symptoms and heart function-related indicators were monitored in children over 7 years of age. Unpaired two-tailed Student’s t tests, Mann‒Whitney U tests, and chi-squared tests were used according to the data type and normality, and a post hoc Bonferroni correction was performed among the intragroup factors. Results A total of 174 DMD children were enrolled, 44 (25.29%) of whom had high cTnI levels (cTnI-H group), including 9.09% of whom had the elevation of cTnI>30-fold. Compared with those in the normal cTnI level group (cTnI-N group), those in the cTnI-H group (100% of the children in the cTnI-H3 group) were aggravated faster (P < 0.001). During follow-up, 20 children in the cTnI-N group had newly elevated cTnI level, and 9.09% of the children’ s cTnI levels in the cTnI-H group had decreased to normal. The elevation of cTnI>30-fold group aggravated faster, and the longest duration was 15 months, in which 100% aggravated faster. Conclusion On the basis of the degree of elevated cTnI, DMD-associated cardiomyopathy can be classified into three different states: a stable stage with normal cTnI, a chronic progressive stage with slightly elevated cTnI, and a rapid progressive stage with significantly elevated cTnI. These three states can alternate and fluctuate with each other. The extent and duration of cTnI elevation are associated with rapid progressive myocardial injury, and regular monitoring of cTnI levels can help identify the rapid progressive myocardial injury at an early stage, and optimize the long-term management of DMD-associated cardiomyopathy.