Myocardial native T mapping and extracellular volume quantification in asymptomatic female carriers of Duchenne muscular dystrophy gene mutations.

Background: Female carriers of dystrophin gene mutations (DMD-FC) were previously considered non-manifesting, but in recent decades, cardiomyopathy associated with muscular dystrophy and myocardial fibrosis has been described. Our study aimed to assess prospectively myocardial fibrosis in asymptomatic DMD-FC compared to a sex-matched control group (CG) with similar age distribution using native T mapping and extracellular volume (ECV) quantification by cardiovascular magnetic resonance (CMR) imaging.

Materials And Methods: 38 DMD-FC with verified genetic mutation and 22 healthy volunteers were included. Using CMR, native T relaxation time and ECV quantification were determined in each group. Late gadolinium enhancement (LGE) was assessed in all cases.

Results: There were 38 DMD-FC (mean age 39.1 ± 8.8 years) and 22 healthy volunteers (mean age 39.9 ± 12.6 years) imagined by CMR. The mean global native T relaxation time was similar for DMD-FC and CG (1005.1 ± 26.3 ms vs. 1003.5 ± 25.0 ms; p-value = 0.81). Likewise, the mean global ECV value was also similar between the groups (27.92 ± 2.02% vs. 27.10 ± 2.89%; p-value = 0.20). The segmental analysis of mean ECV values according to the American Heart Association classification did not show any differences between DMD-FC and CG. There was a non-significant trend towards higher mean ECV values of DMD-FC in the inferior and inferolateral segments of the myocardium (p-value = 0.075 and 0.070 respectively).

Conclusion: There were no statistically significant differences in the mean global and segmental native T relaxation times and the mean global or segmental ECV values. There was a trend towards higher segmental mean ECV values of DMD-FC in the inferior and inferolateral walls of the myocardium.