Smith Brandon M, Dorfman Adam L, Yu Sunkyung, Russell Mark W, Agarwal Prachi P, Ghadimi Mahani Maryam, Lu Jimmy C
Division of Pediatric Cardiology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan.
Division of Pediatric Cardiology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan; Section of Pediatric Radiology, Department of Radiology, University of Michigan, Ann Arbor, Michigan.
Am J Cardiol. 2014 Oct 15;114(8):1275-80. doi: 10.1016/j.amjcard.2014.07.051. Epub 2014 Jul 30.
Evaluation of hypertrophic cardiomyopathy (HC) in young patients is limited by lack of age-specific norms for wall thickness on cardiovascular magnetic resonance (CMR) images. Left ventricular strain may have a role in identifying and risk stratifying patients with HC, but few data exist for strain measurement on CMR images. In 30 patients (14.1 ± 3.2 years) with clinically diagnosed HC and 24 controls (15.6 ± 2.8 years), strain (radial, longitudinal, and circumferential) was evaluated by 2 experienced readers using CMR feature tracking. In patients with HC, hypertrophied segments had decreased radial (28.0 ± 5.2% vs 58.6 ± 3.9%, p = 0.0002), circumferential (-23.7 ± 1.1% vs -28.3 ± 0.8%, p = 0.004), and longitudinal (-11.2 ± 1.2% vs -21.7 ± 0.8%, p <0.0001) strains versus control segments. Hypertrophied segments had decreased longitudinal (basal segments -12.2 ± 1.9% vs -22.6 ± 1.2%, p = 0.0002), radial (basal segments 22.7 ± 10.8% vs 78.8 ± 7.2%, p = 0.0001), and circumferential (basal segments -22.4 ± 1.7% vs -30.6 ± 1%, p = 0.0004) strains versus nonhypertrophied segments in patients with HC. Longitudinal strain had the lowest intraobserver and interobserver variabilities (coefficient of variability -15.7% and -18.5%). After a median follow-up of 28.1 months (interquartile range [IQR] 4.2 to 33.1), 7 patients with HC with an adverse event outcome (5 ventricular tachycardia, 1 appropriate implantable cardioverter-defibrillator discharge, and 1 death) had reduced global radial (median 39.7%, IQR 39.6% to 46.6% vs 65.4%, IQR 46.1% to 83.4%, p = 0.01) and longitudinal strains (median -16.5%, IQR -18.7% to -15.5% vs -19.7%, IQR -23.8% to -17.5%, p = 0.046) compared with patients with HC without an event. In conclusion, CMR feature tracking detects differences in global and segmental strains and may represent a novel method to predict clinical outcome in patients with HC. Further study is necessary to evaluate longitudinal changes in this population.
由于缺乏针对心血管磁共振（CMR）图像上壁厚度的特定年龄规范，年轻患者肥厚型心肌病（HC）的评估受到限制。左心室应变可能在HC患者的识别和风险分层中发挥作用，但关于CMR图像上应变测量的数据很少。在30例临床诊断为HC的患者（14.1±3.2岁）和24例对照者（15.6±2.8岁）中，2名经验丰富的阅片者使用CMR特征追踪评估了应变（径向、纵向和圆周向）。在HC患者中，肥厚节段的径向应变（28.0±5.2%对58.6±3.9%，p = 0.0002）、圆周向应变（-23.7±1.1%对-28.3±0.8%，p = 0.004）和纵向应变（-11.2±1.2%对-21.7±0.8%，p<0.0001）均低于对照节段。与HC患者的非肥厚节段相比，肥厚节段的纵向应变（基底部节段-12.2±1.9%对-22.6±1.2%，p = 0.0002）、径向应变（基底部节段22.7±10.8%对78.8±7.2%，p = 0.0001）和圆周向应变（基底部节段-22.4±1.7%对-30.6±1%，p = 0.0004）降低。纵向应变的观察者内和观察者间变异性最低（变异系数分别为-15.7%和-18.5%）。在中位随访28.1个月（四分位间距[IQR]4.2至33.1）后，7例有不良事件结局的HC患者（5例室性心动过速、1例植入式心律转复除颤器恰当放电和1例死亡）的整体径向应变（中位数39.7%，IQR 39.6%至46.6%对65.4%，IQR 46.1%至83.4%，p = 0.01）和纵向应变（中位数-16.5%，IQR -18.7%至-15.5%对-19.7%，IQR -23.8%至-17.5%，p = 0.046）低于无事件的HC患者。总之，CMR特征追踪可检测整体和节段应变的差异，可能代表一种预测HC患者临床结局的新方法。有必要进一步研究评估该人群的纵向变化。
