心脏磁共振特征追踪技术在检测成人非梗阻性肥厚型心肌病患者心肌纤维化中的应用

Application of cardiac magnetic resonance feature tracking in the detection of myocardial fibrosis in adult patients with non-obstructive hypertrophic cardiomyopathy

目的:应用心脏磁共振特征追踪(CMR-FT)技术评价成人非梗阻性肥厚型心肌病(HCM)患者的心肌纤维化。方法:回顾性纳入2016年11月至2020年4月就诊于云南省第一人民医院行CMR检查的成人非梗阻性HCM患者,通过延迟钆增强(LGE)判断心肌纤维化,使用CMR-FT软件获得心脏三维的整体和局部纵向、周向和径向的应变和应变率,比较有LGE和无LGE的HCM患者的整体应变和应变率的差异,以及有LGE和无LGE的心肌节段局部应变和应变率的差异。结果:共纳入86例HCM患者,其年龄为(45±8)岁,男性71例,其中,64例(74%)患者存在LGE。LGE阳性与LGE阴性患者在年龄、左心室射血分数、左心室舒张末期容积、左心室质量及左心室质量指数方面差异有统计学意义(P均<0.05)。LGE阳性患者的整体应变[纵向:(-7.6±3.4)%比(-14.3±2.5)%,周向:(-9.4±1.9)%比(-17.2±1.6)%,径向(10.3±2.1)%比(17.9±3.5)%]和应变率[纵向:(-89.0±16.3)s^(-1)比(-123.5±13.1)s^(-1),周向:(-92.5±13.5)s^(-1)比(-137.0±12.6)s^(-1),径向:(80.9±9.9)s^(-1)比(129.1±22.3)s^(-1)]均低于LGE阴性患者,差异有统计学意义(P均<0.05)。64例有LGE患者中除心尖外共1024个节段,其中256个节段有LGE,有LGE的心肌节段的局部应变[纵向:(-8.1±2.2)%比(-15.2±3.9)%,周向:(-9.7±1.1)%比(-16.8±1.3)%,径向:(11.7±3.0)%比(19.7±2.6)%]和应变率[纵向:(-92.7±18.4)s^(-1)比(-127.1±12.7)s^(-1),周向:(-90.5±11.2)s^(-1)比(-129.4±11.7)s^(-1),径向:(81.6±7.9)s^(-1)比(135.7±19.5)s^(-1)]也低于无LGE的心肌节段,差异也有统计学意义(P均<0.01)。接受者操作特征(ROC)曲线显示,整体纵向应变(GLS)在诊断非梗阻性HCM心肌纤维化时的曲线下面积(AUC)值为0.763(95%可信区间61.2%~91.4%),GLS界值为-11.7%时的敏感性为91%,特异性为89%。结论:在成人非梗阻性HCM患者中应用CMR-FT技术检测的心肌整体和局部应变和应变率在有LGE与无LGE的患者及心肌节段间存在显著差异,提示可以应用CMR-FT技术在不使用钆对比剂的情况下评价成人非梗阻性HCM患者的心肌纤维化。

Objective:To investigate the application of cardiac magnetic resonance feature tracking(CMR-FT)in the detection of myocardial fibrosis in adult patients with non-obstructive hypertrophic cardiomyopathy(HCM).Methods:Adult patients with the diagnosis of non-obstructive HCM in the First People′s Hospital of Yunnan Province from November 2016 to April 2020 were retrospectively enrolled and CMR imaging was performed to detect myocardial fibrosis by late gadolinium enhancement(LGE).Three-dimensional global and regional longitudinal,circumferential and radial strain and strain rate were obtained by CMR-FT software and compared between HCM patients with LGE and those without LGE as well as myocardial segment with LGE and those without LGE.Results:A total of 86 patients with non-obstructive HCM were enrolled,with the age of(45±8)years and 71 males,of whom 64 patients(74%)had LGE.There were significant differences in age,left ventricular ejection fraction,left ventricular end-diastolic volume,left ventricular mass and left ventricular mass index between patients with LGE and those without LGE(all P<0.05).The global strain[longitudinal(-7.6±3.4)%vs.(-14.3±2.5)%,circumferential(-9.4±1.9)%vs.(-17.2±1.6)%,radial(10.3±2.1)%vs.(17.9±3.5)%,all P<0.01]and strain rate[longitudinal(-89±16.3)s-1 vs.(-123.5±13.1)s-1,circumferential(-92.5±13.5)s-1 vs.(-137.0±12.6)s-1,radial(80.9±9.9)s-1 vs.(129.1±22.3)s-1,all P<0.05]of patients with LGE were significantly lower than those of patients without LGE.In 64 patients with LGE,there were 1024 segments except apical segment,of which 256 segments had LGE.There were also significantly lower regional strain[longitudinal(-8.1±2.2)%vs.(-15.2±3.9)%,circumferential(-9.7±1.1)%vs.(-16.8±1.3)%,radial(11.7±3.0)%vs.(19.7±2.6)%,all P<0.01]and strain rate[longitudinal(-92.7±18.4)s-1 vs.(-127.1±12.7)s-1,circumferential(-90.5±11.2)s-1 vs.(-129.4±11.7)s-1,radial(81.6±7.9)s-1 vs.(135.7±19.5)s-1,all P<0.001]in myocardial segment with LGE compared to those without LGE.The receiver operating characteristic(ROC)curve showed the area under the curve(AUC)for global longitudinal strain(GLS)in detection of myocardial fibrosis was 0.763(95%confidence interval of 61.2%-91.4%),with the sensitivity and specificity of 91%and 89%at the cut-off value of-11.7%.Conclusion:The myocardial strain and strain rate detected by CMR-FT technique in adult patients with non-obstructive HCM were significantly different between patients with LGE and those without LGE as well as myocardial segment with LGE and those without LGE,suggesting that CMR-FT technique can be used to evaluate myocardial fibrosis in adult non-obstructive HCM patients without gadolinium contrast agent.