Patients with Duchenne muscular dystrophy (DMD) who can walk beyond the age of 12 appear to have better cardiac function during adulthood, according to a recently published study in Neuromuscular Disorders.
The authors aimed to assess the relationship between motor and cardiac function in patients with DMD through a retrospective analysis of the clinical history of 84 patients with DMD. All of the patients received corticosteroid treatment to delay cardiac complications between 1989 and 2024.
Data analysis revealed that patients who lost their ambulation ability later in life appeared to have better cardiac function during adulthood. Researchers used the left ventricular ejection fraction (LVEF) as a marker of cardiac function. LVEF is a measure of how much blood the heart pumps each time it contracts. In patients with heart failure (HF), the LVEF is usually under 50%.
Patients who lost ambulation before turning 12 were almost five times more likely to have an LVEF below 40% during adulthood.
According to the study, the positive correlation between preserved ambulation and better LVEF was independent of each patient’s genetic variant.
“The main finding of this retrospective analysis is that individuals with DMD who retain the ability to walk to an older age maintain their LV function better into adulthood compared to those who lost ambulation at a younger age,” the authors concluded.
Read more about DMD prognosis
About cardiac dysfunction in DMD
Cardiac dysfunction typically arises as patients with DMD grow older. Although structural heart changes are found in some patients younger than 12, most patients begin to experience cardiac symptoms during early adulthood.
Cardiomyopathy (enlargement of the heart muscle tissue that impacts its ability to pump blood) is currently the main cause of death among patients with DMD. Therefore, there is a growing interest in discovering markers that allow physicians to evaluate risk and treat accordingly.
Some experts have raised concerns that prolonging how long a patient continues to walk could increase their risk of cardiomyopathy by increasing the stress on the heart. The authors expect that this and future studies will dispel those fears.
“The results may reduce concerns that prolonged ambulation is deleterious to longer-term cardiac function in DMD,” the authors wrote. “This message is relevant in the era when potent disease-modifying treatments, such as gene therapy, advanced exon skipping, and antifibrotic molecules, are either under development or at the stage of clinical testing,”
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