Department of Pediatrics, Division of Pediatric Cardiology and Radiology.
Circ Cardiovasc Imaging. 2013 Nov;6(6):873-80. doi: 10.1161/CIRCIMAGING.113.000798. Epub 2013 Oct 4.
More than 50% of >270 000 childhood cancer survivors in the United States have been treated with anthracyclines and are therefore at risk of developing cardiotoxicity. Cardiac magnetic resonance (CMR) has demonstrated utility to detect diffuse interstitial fibrosis and changes in regional myocardial function. We hypothesized that CMR would identify occult cardiotoxicity characterized by structural and functional myocardial abnormalities in a cohort of asymptomatic pediatric cancer survivors with normal global systolic function.
Forty-six long-term childhood cancer survivors with a cumulative anthracycline dose ≥200 mg/m(2) and normal systolic function were studied 2.5 to 26.9 years after anthracycline exposure. Subjects underwent transthoracic echocardiography, CMR with routine cine acquisition, tissue characterization, and left ventricular strain analysis using a modified 16-segment model. Extracellular volume was measured in 27 subjects, all of whom were late gadolinium enhancement negative. End-systolic fiber stress was elevated in 45 of 46 subjects. Low average circumferential strain magnitude (εcc) -14.9±1.4; P<0.001, longitudinal strain magnitude (εll) -13.5±1.9; P<0.001, and regional peak circumferential strain were seen in multiple myocardial segments, despite normal global systolic function by transthoracic echocardiography and CMR. The mean T1 values of the myocardium were significantly lower than that of control subjects at 20 minutes (458±69 versus 487±44 milliseconds; P=0.01). Higher mean extracellular volume was observed in female subjects (0.34 versus 0.22; P=0.01).
Asymptomatic postchemotherapy pediatric patients have abnormal myocardial characteristics and strain parameters by CMR despite normal global cardiac function by standard transthoracic echocardiography and CMR measures.
在美国，超过 270000 名儿童癌症幸存者中，有超过 50%的患者接受了蒽环类药物治疗，因此存在发生心脏毒性的风险。心脏磁共振（CMR）已被证明可用于检测弥漫性间质纤维化和区域性心肌功能变化。我们假设 CMR 可以识别隐匿性心脏毒性，即在一组无明显症状的儿童癌症幸存者中，尽管整体左心室收缩功能正常，但存在结构性和功能性心肌异常。
对 46 名长期儿童癌症幸存者进行了研究，这些患者在接受蒽环类药物治疗后 2.5 至 26.9 年，蒽环类药物累积剂量≥200mg/m2，且左心室收缩功能正常。患者接受了经胸超声心动图、CMR 常规电影采集、组织特征分析以及使用改良的 16 节段模型进行左心室应变分析。27 名患者进行了细胞外容积测量，所有患者均为晚期钆增强阴性。46 名患者中有 45 名患者的左心室收缩末期纤维应力升高。尽管经胸超声心动图和 CMR 显示整体左心室收缩功能正常，但多个节段的平均圆周应变幅度（εcc）为-14.9±1.4（P<0.001）、平均纵向应变幅度（εll）为-13.5±1.9（P<0.001）和区域性峰值圆周应变均降低。心肌的平均 T1 值明显低于对照组，在 20 分钟时为 458±69 毫秒与 487±44 毫秒（P=0.01）。女性患者的平均细胞外容积较高（0.34 比 0.22；P=0.01）。
尽管标准经胸超声心动图和 CMR 测量的整体心脏功能正常，但接受过化疗的无症状儿科患者通过 CMR 存在心肌特征和应变参数异常。
