Prognosis of Duchenne muscular dystrophy (DMD) is related to cardiac dysfunction, occurring in the second decade. The prevention of cardiomyopathy stands as one of the most challenging clinical research issues in children with DMD. Speckle tracking echocardiography (STE) is emerging as a functional biomarker to consider in the early detection of DMD-related cardiomyopathy.

Prospective controlled study in DMD children with normal or mildly altered left ventricle ejection fraction (LVEF≥45%), compared with healthy age- and gender-matched controls. Left ventricle (LV) and right ventricle (RV) conventional echocardiography was performed, along with STE analyses in LV longitudinal, radial, and circumferential and RV free wall longitudinal displacements. The effect of age on STE evolution in DMD children was evaluated.

The study included 108 boys, of which 36 DMD (mean age 11±3.8 y) and 72 matched controls. Conventional echocardiographic measures were normal in both groups and for both ventricles. LVEF ranged from 45% to 76% (mean 63%±6%) in DMD group and from 55% to 76% (mean 64%±5%) in controls. Global LV strain mean measures were significantly lower in the DMD group for the longitudinal (−16.8%±3.9% vs. −20.6%±2.6%, P<0.0001), radial (+22.7%±11.3% vs.+31.7%±14%, P=0.002), and circumferential (−16.5%±3.8% vs.−20.3%±3.1%, P<0.0001) displacements (Fig. 1). The LV longitudinal strain decrease with age in DMD children was 0.34% per year more marked than that of the controls. The LV inferolateral and anterolateral basal segments were specifically impaired. RV function with conventional and ST echocardiography was normal and not significantly different between DMD and controls (Fig. 1).

The existence of an altered LV strain despite normal or subnormal LVEF in children with DMD represents an important perspective for future drug trials in DMD-related cardiomyopathy prevention.

Clinicaltrials.gov NCT02418338.