Novel implementation of cardiac magnetic resonance first-pass perfusion imaging for semi-quantitatively evaluating microvascular dysfunction in paediatric patients with Duchenne muscular dystrophy

Objectives: The current study aimed to assess myocardial microcirculation dysfunction via cardiac magnetic resonance (CMR) first-pass perfusion imaging in children with Duchenne muscular dystrophy (DMD). Methods: In total, 67 children with DMD and 15 controls who underwent contrast-enhanced CMR first-pass perfusion imaging were enrolled in this study. CMR first-pass perfusion and late gadolinium enhancement (LGE) sequences were acquired. Further, the global, regional, and coronary artery distribution area perfusion indexes (PI), upslope (%BL), maximum signal intensity (MaxSI), time to maximum signal intensity (TTM), and baseline SI were analysed. The perfusion parameters of the LGE positive (thorn), LGE negative (-), and control groups were compared. Pearson correlation analysis was performed to assess the association between myocardial microcirculation and conventional cardiac function and LGE parameters. Results: The LGE+ group had a significantly lower global and apical-ventricular MaxSI than the control group (all P<.05). The left anterior descending arterial (LAD), left circumflex coronary arterial (LCX), and right coronary arterial (RCA) segments of the LGE+ group had a lower up-slope and MaxSI than those of the control group (all P<.05). The LAD segments of the LGE- group had a lower MaxSI than those of the control group (41.10 +/- 11.08 vs 46.36 +/- 13.04; P<.001). The LCX segments of the LGE- group had a lower PI and upslope than those of the control group (11.05 +/- 2.84 vs 12.46 +/- 2.82; P =.001; 59.31 +/- 26.76 vs 68.57 +/- 29.99; P =.002). Based on the correlation analysis, the upslope, MaxSI, and TTM were correlated with conventional cardiac function and LGE extent. Conclusions: Paediatric patients with DMD may present with microvascular dysfunction. This condition may appear before LGE and may be correlated with coronary artery blood supply and LGE extent. Advances in knowledge: First-pass perfusion parameters may reveal the status of myocardial microcirculation and reflect the degree of myocardial injury at an earlier time in DMD patients. Perfusion parameters should be analysed not only via global or base, middle, and apical segments but also according to coronary artery distribution area, which may detect myocardial microvascular dysfunction at an earlier stage, in DMD patients with LGE-.