Cardiovascular outcomes and prognostic factors in 617 patients with dystrophinopathies: a single-centre cohort study

Background/Introduction Cardiomyopathy has become a leading cause of morbidity and mortality in patients with dystrophinopathies as life expectancy has improved. Despite this growing clinical burden, large-scale data on cardiovascular outcomes and risk factors in this population are limited. Purpose This study aimed to evaluate cardiac outcomes and identify predictors of adverse events in patients with Duchenne and Becker muscular dystrophy (DMD and BMD) followed at a single tertiary centre. Methods We retrospectively reviewed 617 genetically confirmed patients with muscular dystrophy who underwent serial echocardiographic follow-up at our tertiary centre between 1998 and 2025. Clinical data, echocardiographic parameters, and medication history were obtained through detailed chart review. Cardiomyopathy and mortality outcomes were assessed, and potential predictors of adverse cardiovascular events were analysed. Results A total of 617 genetically confirmed patients with dystrophinopathies were analysed, including 302 with DMD, 135 with BMD, and 62 DMD outliers. The mean age at initial echocardiographic evaluation was 8.3 ± 4.7 years, with a mean follow-up duration of 11.2 ± 5.5 years. Cardiomyopathy developed in 65.6% of patients, with a mean onset age of 15.1 ± 4.9 years. DMD patients developed cardiomyopathy earlier than BMD patients (14.6 ± 4.6 years vs. 18.0 ± 5.3 years, p = 0.001). During follow-up, 72 patients (11.7%) died at a mean age of 19.9 ± 4.3 years, and survival was significantly poorer in DMD compared with BMD patients (log-rank p < 0.001). Heart failure admission occurred in 37 patients (6%) and was associated with increased mortality risk (HR 3.95, 95% CI 2.33–6.70). Angiotensin-converting enzyme inhibitor (ACEi) or angiotensin II receptor blocker (ARB) was prescribed in 383 patients. Those who initiated ACEi/ARB therapy with preserved left ventricular (LV) function (LV ejection fraction≥ 50%) had improved survival compared with those who started treatment after LV dysfunction (HR 0.414, 95% CI 0.218–0.786, p = 0.007). Patients who developed LV dysfunction before the age of 16 showed higher mortality risk (HR 1.965, 95% CI 1.231–3.134). In multivariable analysis, independent predictors of mortality included DMD subtype, ACEi/ARB therapy initiation after LV dysfunction, worst LV ejection fraction < 40%, heart failure admission, and early-onset cardiomyopathy. Conclusions Cardiomyopathy and mortality remain major cardiovascular burdens in patients with dystrophinopathies, particularly among those with Duchenne muscular dystrophy. Early cardiac surveillance and initiation of ACE inhibitor or ARB therapy before LV dysfunction may improve long-term survival in this population.