Arterial Stiffness in patients with Duchenne muscular dystrophy

Rationale: Cardiomyopathy in Duchenne muscular dystrophy (DMD) is frequent and characterized by progressive left ventricular (LV) fibrosis leading to dysfunction and dilatation. Factors increasing LV afterload, such as aortic stiffness, may promote LV wall stress and lead to worsening of LV function. DMD patients are currently treated with Angiotensin converting enzyme inhibitors (ACEi) to delay onset and progression of LV dysfunction but the working mechanism of this medication remains largely unknown.

Objective: We aim to investigate if aortic stiffness, measured by pulse wave velocity (PWV), is present in patients with DMD. Next, we aim to investigate if treatment with ACEi reduces aortic stiffness over time and the influence on cardiac function.

Study design: This prospective observational study has a cross sectional and longitudinal part.
-Cross sectional part: PWV measurement will be performed using the Arteriograph. Echocardiography will be performed to investigate the cardiac function.
-Longitudinal part: will exist of patients that have an indication for ACEi therapy from regular care. PWV will be measured 3, 6 and 9 months after the start of ACEi. Echocardiography will be performed to investigate the cardiac function.

Study population: DMD patients between 4-15 years that do not use ACEi or any other cardiac medication.

Main study parameters/endpoints: The primary end-point of this study is the difference in PWV between DMD patients and published paediatric reference values.
The primary end point of the follow up part of the study is the difference between PWV in DMD patients before and after the start of ACEi.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The PWV measurement by the Arteriograph has no known risks due to its non-invasive nature. Patients will not directly benefit from participating in the study. A better understanding of the course of cardiovascular changes and the influence of ACEi treatment could lead to refinement and a more individualist ACEi treatment strategy for DMD patients in the future.

Aortic stiffness is increased in DMD patients due to the absence of dystrophin. Aortic stiffness is reduced by ACEi therapy, which reduces the progression of LV dysfunction.

Cross sectional part: Baseline visit: assessment of PWV and cardiac function

Longitudinal part: assessment of PWV 3, 6, 9 months after start ACEi. Assessment of cardiac function 9 months after start ACEi.