Boys With Duchenne Muscular Dystrophy Have Diastolic Dysfunction Based on CMR

Area of Science:

• Cardiology
• Neuromuscular Disorders
• Medical Imaging

Background:

• Cardiomyopathy is a primary cause of death in Duchenne muscular dystrophy (DMD).
• Cardiac magnetic resonance (CMR) is used for assessing fibrosis and left ventricular (LV) ejection fraction in DMD.
• CMR-derived measures of LV filling and ejection dynamics in DMD have not been previously reported.

Purpose of the Study:

• To investigate and compare LV filling and ejection dynamics between DMD patients and healthy controls using CMR.
• To identify potential prognostic value of these dynamic CMR measures in DMD patients.

Main Methods:

• Prospective enrollment of 179 DMD patients and 96 healthy controls for CMR.
• Measurement of standard LV volumes, ejection fraction, and detailed LV filling and ejection curves from baseline CMR.
• Utilized multivariable linear regressions for group comparisons and Cox regressions to assess mortality associations with diastolic function.

Main Results:

• DMD patients exhibited smaller ventricular volumes and lower LV ejection fraction compared to controls (P<0.001).
• Adjusted analyses revealed significantly slower peak filling rates (P<0.001) and peak ejection rates (P<0.001) in DMD patients.
• Lower peak ventricular ejection and filling rates, normalized to LV end-diastolic volume, were associated with increased mortality in DMD patients.

Conclusions:

• DMD patients demonstrate significantly different baseline CMR-derived LV filling and ejection indices compared to controls.
• Certain LV filling indices show association with mortality, suggesting potential as prognostic markers.
• Further research in larger cohorts is warranted to confirm the prognostic value of these CMR-derived indices.