Skeletal and cardiac function are correlated in dystrophinopathies: a study using cardiac MRI and the MFM scale.

Background: Cardiomyopathy is almost universal in dystrophinopathies and the leading cause of death in this population. Despite this, there are few studies that correlated cardiac structural changes with motor function in dystrophinopathies. Objective: This cross-sectional study aims to characterize myocardial tissue remodeling in patients with Duchenne and Becker muscular dystrophies (DMD/BMD) and investigate its correlation with motor function. Methods: In the same week, 27 patients with DMD and 23 with BMD aged 7 years and older and 10 sex-matched healthy individuals underwent to a comprehensive evaluation including laboratory workup, MFM-32 scale and 3.0 T cardiac magnetic resonance imaging. Results: The BMD group presented mean age of 27.1 ± 16.4 years, disease duration of 19.9 ± 14.2 years and MFM-32 score of 64.8 ± 22.0%. The DMD group presented mean age of 12.8 ± 5.3 years, disease duration of 8.0 ± 6.1 years and MFM-32 score of 53.3 ± 21.8%. Both BMD and DMD groups presented subepicardial late gadolinium enhancement (LGE) and lower LVEF values compared to controls (respectively 53.49 ± 12.82% versus 62.65 ± 2.81%, P= 0.008 and 60.43 ± 6.94% versus 62.65 ± 2.81%, P= 0.037). The LVEF values correlated directly with MFM-32 scale in BMD and DMD (respectively R= 0.73 P < 0.001 and R= 0.536 P = 0.007). DMD presented higher Native T1 than controls (1252.27 ± 62.21 ms versus 1180.59 ± 59.40 ms, P= 0.016) and BMD group presented higher ECV than controls (0.31 ± 0.07 versus 0.27 ± 0.03, P= 0.042). This parameter correlated directly with duration of disease (R= 0.66 P < 0.001) and inversely with MFM-32 (R= -0.64 P= 0.002) in BMD group, while T1 native correlated with pro-BNP levels in DMD (R= 0.51 P= 0.01). In the multiple regression model, LVEF correlated with the MFM-32 scale in the DMD group (R² adjusted= 0.22 Regression coefficient= 0.158, P= 0.031), but not with the disease duration. Conclusions: This study indicates that ECV and T1 native proved useful to detect myocardial microstructural remodelling in dystrophinopathies. Cardiac and motor function are related processes, which are driven by the amount of dystrophin underexpression. [ABSTRACT FROM AUTHOR]