Spurney Christopher F, McCaffrey Francis M, Cnaan Avital, Morgenroth Lauren P, Ghelani Sunil J, Gordish-Dressman Heather, Arrieta Adrienne, Connolly Anne M, Lotze Timothy E, McDonald Craig M, Leshner Robert T, Clemens Paula R
Children's National Health System, Washington, District of Columbia.
Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania.
J Am Soc Echocardiogr. 2015 Aug;28(8):999-1008. doi: 10.1016/j.echo.2015.03.003. Epub 2015 Apr 21.
Cardiac disease is a major cause of death in patients with muscular dystrophies. The use of feasible and reproducible echocardiographic measures of cardiac function is critical to advance the field of therapeutics for dystrophic cardiomyopathy.
Participants aged 8 to 18 years with genetically confirmed Duchenne muscular dystrophy (DMD), Becker muscular dystrophy, or limb-girdle muscular dystrophy were enrolled at five centers, and standardized echocardiographic examinations were performed. Measures of systolic and diastolic function and speckle-tracking echocardiography-derived cardiac strain were reviewed independently by two central readers. Furthermore, echocardiographic measures from participants with DMD were compared with those from retrospective age-matched control subjects from a single site to assess measures of myocardial function.
Forty-eight participants (mean age, 13.3 ± 2.7 years) were enrolled. Shortening fraction had a greater interobserver correlation (intraclass correlation coefficient [ICC] = 0.63) compared with ejection fraction (ICC = 0.49). One reader could measure ejection fraction in only 53% of participants. Myocardial performance index measured by pulse-wave Doppler and Doppler tissue imaging showed similar ICCs (0.55 and 0.54). Speckle-tracking echocardiography showed a high ICC (0.96). Focusing on participants with DMD (n = 33), significantly increased mitral A-wave velocities, lower E/A ratios, and lower Doppler tissue imaging mitral lateral E' velocities were observed compared with age-matched control subjects. Speckle-tracking echocardiography demonstrated subclinical myocardial dysfunction with decreased average circumferential and longitudinal strain in three distinct subgroups: participants with DMD with normal shortening fractions, participants with DMD aged < 13 years, and participants with DMD with myocardial performance index scores < 0.40 compared with control subjects.
In a muscular dystrophy cohort, assessment of cardiac function is feasible and reproducible using shortening fraction, diastolic measures, and myocardial performance index. Cardiac strain measures identified early myocardial disease in patients with DMD.
心脏病是肌肉营养不良患者的主要死因。采用可行且可重复的超声心动图测量心脏功能对于推动营养不良性心肌病的治疗领域发展至关重要。
在五个中心招募了年龄在8至18岁、基因确诊为杜氏肌营养不良（DMD）、贝克肌营养不良或肢带型肌营养不良的参与者，并进行了标准化的超声心动图检查。两名中心阅片者独立审查收缩和舒张功能测量值以及斑点追踪超声心动图得出的心脏应变。此外，将DMD参与者的超声心动图测量值与来自单一地点的回顾性年龄匹配对照受试者的测量值进行比较，以评估心肌功能测量值。
共招募了48名参与者（平均年龄13.3±2.7岁）。与射血分数（组内相关系数[ICC]=0.49）相比，缩短分数具有更高的观察者间相关性（ICC=0.63）。一名阅片者仅能在53%的参与者中测量射血分数。通过脉冲波多普勒和多普勒组织成像测量的心肌性能指数显示出相似的ICC（分别为0.55和0.54）。斑点追踪超声心动图显示出较高的ICC（0.96）。聚焦于DMD参与者（n=33），与年龄匹配的对照受试者相比，观察到二尖瓣A波速度显著增加、E/A比值降低以及多普勒组织成像二尖瓣外侧E'速度降低。斑点追踪超声心动图显示在三个不同亚组中存在亚临床心肌功能障碍，平均圆周应变和纵向应变降低：缩短分数正常的DMD参与者、年龄<13岁的DMD参与者以及与对照受试者相比心肌性能指数评分<0.40的DMD参与者。
在肌肉营养不良队列中，使用缩短分数、舒张测量值和心肌性能指数评估心脏功能是可行且可重复的。心脏应变测量发现了DMD患者的早期心肌疾病。
