Progressive left ventricular dysfunction and myocardial fibrosis in Duchenne and Becker muscular dystrophy: a longitudinal cardiovascular magnetic resonance study

摘要

This study examined the progression of left ventricular dysfunction and myocardial fibrosis in patients with Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) to evaluate the effects of angiotensin-converting enzyme inhibitor (ACEI). Ninety-eight cardiovascular magnetic resonance (CMR) studies in 34 consecutive patients with DMD (n=21) or BMD (n=13) were retrospectively reviewed. Left ventricular ejection fraction (LVEF) and the extent of myocardial late gadolinium enhancement (LGE) were semiautomatically quantified. During the study period, five patients had already been treated with ACEI at the first CMR; five were started on ACEI at LVEF55% and 10at LVEF<55%. All patients had hyperenhanced myocardium on LGE images at the first CMR (median extent, 3.3%; interquartile range 0.1-14.3%). A mixed-effects model for longitudinal data of each patient, adjusted for age, type of muscular dystrophy, steroid use, and ACEI use showed that higher age (=-1.1%/year; 95% confidence interval [CI], -1.8% to -0.4%; p=0.005) and no use of ACEI (=-3.1%; 95% CI, -5.4% to -0.8%; p=0.009) were significantly associated with a lower LVEF. When ACEI use was stratified by time of initiation (LVEF55% vs. <55%), only ACEI initiation at LVEF<55% had a beneficial effect on LVEF at each imaging examination (=3.7%; 95% CI, 0.9-6.4%; p=0.010). ACEI use or the time of initiation of ACEI did not significantly affect age-related increase in LGE. ACEI attenuated the age-related decline in LVEF only in patients with DMD or BMD and reduced LVEF, suggesting that further investigation on prophylactic use of cardioprotective therapy in these patients is warranted.