Cardiac MRI and Echocardiography for Early Diagnosis of Cardiomyopathy Among Boys With Duchenne Muscular Dystrophy: A Cross-Sectional Study

Abstract

BackgroundCardiomyopathy is an important cause of morbidity and mortality in boys with Duchenne muscular dystrophy (DMD). Early diagnosis is a prerequisite for timely institution of cardioprotective therapies.ObjectiveWe compared cardiac MRI (CMRI) with transthoracic echocardiography (TTE) including tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) for diagnosis of cardiomyopathy in early ambulatory boys with DMD.MethodologyThis cross-sectional study was conducted between June 2018 and December 2020. Consecutive boys between 7 and 15 years of age with DMD were enrolled. Percentage ejection fraction (EF), fractional shortening, wall motion abnormalities, early diastolic mitral annulus velocity (Ea), medial mitral annulus ratio (E/Ea), and global strain were measured with STE. CMRI-derived EF, segmental hypokinesia, and late gadolinium enhancement (LGE) were studied and compared.ResultsA total of 38 ambulatory boys with DMD were enrolled. The mean age was 8.8 ± 1.6 years, and none had clinical features suggestive of cardiac dysfunction. In the TTE, EF was ≤55% in 5 (15%), FS was ≤28% in 3 (9%), and one each had left ventricular wall thinning and wall hypokinesia. In TDI, none had diastolic dysfunction, and STE showed reduced global strain of < 18% in 3 (9%) boys. CMRI-derived EF was ≤55% in 20 (53%) boys and CMRI showed the presence of left ventricular wall hypokinesia in 9 (24%) and LGE in 4 (11%) boys.ConclusionCardiomyopathy remains clinically asymptomatic among early ambulatory boys with DMD. A significantly higher percentage of boys revealed early features of DMD-related cardiomyopathy in CMRI in comparison with echocardiography.

Utilidad de la resonancia magnética cardíaca en pacientes con distrofias neuromusculares (distrofia neuromuscular de Duchene/ Becker)

“…En consecuencia, concluimos que la RMC debe realizarse de forma rutinaria y temprana en niños con DMD, no solo para obtener imágenes de LGE sino también para la evaluación funcional. (17,18) La utilidad de la RMC para diagnóstico de fibrosis es superior a la de otros métodos de imágenes; se la debe asociar al uso rutinario de otros métodos complementarios de diagnóstico como el Electrocardiograma, Ecocardiograma Doppler y Strain por speckle tracking para con ello decidir conductas preventivas. Es el método de elección para valoración de la FEVI, volúmenes ventriculares y masa del VI.…”

Usefulness of Cardiac Magnetic Resonance Imaging in Patients with Neuromuscular Dystrophies (Duchenne/Becker Muscular Dystrophy)

“…Accordingly, we conclude that CMR should be performed routinely and early in children with DMD, not only for LGE imaging but also for functional assessment. (17,18) CMR has a better diagnostic field for the identification of fibrosis than other imaging methods; it should be associated with other routine complementary diagnostic methods such as ECG, Doppler echocardiography and speckle tracking strain in order to decide on preventive measures. It is the technique of choice to assess LVEF, left and right ventricular volumes and LV mass.…”

Myocardial strain imaging in Duchenne muscular dystrophy

“…By tracking the motion of these speckles through space and time around a given point in the tissue, one can derive the “motion description” of strain, i.e., Lagrangian strain, in which deformation of the myocardium is tracked from a fixed reference point at end-diastole ( 30 ). Strain mapping with 2D-STE has been shown to be useful for early detection of cardiac dysfunction retrospectively in DMD patients and prospectively in canine models of DMD even prior to gross changes in LVEF ( 12 , 37 , 40 , 41 ). In one notable recent study of 38 ambulatory boys with DMD (mean age 8.8 ± 1.6 years) 9% showed reduced global strain (< 18%) on 2D-STE prior to clinical features suggestive of cardiac dysfunction ( 41 ).…”

“…Strain mapping with 2D-STE has been shown to be useful for early detection of cardiac dysfunction retrospectively in DMD patients and prospectively in canine models of DMD even prior to gross changes in LVEF ( 12 , 37 , 40 , 41 ). In one notable recent study of 38 ambulatory boys with DMD (mean age 8.8 ± 1.6 years) 9% showed reduced global strain (< 18%) on 2D-STE prior to clinical features suggestive of cardiac dysfunction ( 41 ).…”