Objective: To quantitatively assess cardiac functions in patients with cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance-feature tracking (CMR-FT) technique and evaluate the prognostic value of CMR-FT in patients with CA.
Methods: We retrospectively collected the data from 31 CA patients with systemic amyloidosis confirmed by Congo red staining and serum immunohistochemistry after extracardiac tissue biopsy undergoing CMR at our hospital from March, 2013 to June, 2021.Thirty-one age and gender matched patients with asymmetric left ventricular wall hypertrophy and 31 healthy individuals without organic or functional heart disease served as the controls.Radial, circumferential and longitudinal strains and strain rates of the left ventricle at the global level and in each myocardial segment (basal, middle and apical) were obtained with CMR-FT technique and compared among the 3 groups.The predictive value of myocardial strains and strain rates for all-cause mortality in CA patients was analyzed using a stepwise COX regression model.
Results: The left ventricular volume, myocardial mass, ejection fraction and cardiac output differed significantly among the groups (P < 0.05).Except for apical longitudinal strain, the global and segmental strains were all significantly lower in CA group than in HCM group (P < 0.05).The global and segmental strains were all significantly lower in CA group than in the healthy individuals (P < 0.05).The basal strain rates in the 3 directions were significantly lower in CA group than in the healthy individuals (P < 0.05), but the difference in apical strain rates was not statistically significant between the two groups.Multivariate stepwise COX analysis showed that troponin T (HR=1.05, 95%CI: 1.01-1.10, P=0.017) and middle peak diastolic circumferential strain rate (HR=6.87, 95%CI: 1.52-31.06, P=0.012) were strong predictors of death in CA patients.
Conclusion: Strain and strain rate parameters derived from CMR-FT based on cine sequences are new noninvasive imaging markers for assessing cardiac impairment in CA and cardiac function changes in HCM, and provide independent predictive information for all-cause mortality in CA patients.
目的: 应用心脏磁共振特征追踪(CMR-FT)技术定量评估心肌淀粉样变性(CA)与肥厚性心肌病(HCM)患者心脏功能的差异且评估其对CA患者的预后价值。
方法: 回顾性收集2013年3月~2021年6月在我院接受CMR检查的31例经心外组织活检并经刚果红染色和血清免疫组织化学检查证实其存在系统性淀粉样变性的CA患者, 并且随机选取年龄和性别相仿的31例非对称左心室室壁肥厚的HCM患者及31例无器质性及功能性心脏病的健康人(NC)作为CA组的对照组。通过CMR-FT技术得到左心室整体及各水平(基底部、中间部及心尖部)径向、周向和纵向应变及应变率, 分析各参数的组间差异。用逐步COX回归模型分析应变及应变率对CA患者全因死亡率的预测价值。
结果: 3组患者的左心室收缩末期容积、心肌质量、射血分数及心输出量的差异均有统计学意义(P均 < 0.05)。除了心尖部纵向应变, CA组患者整体及各水平应变均明显低于HCM组(P均 < 0.05)。CA组患者整体及各水平应变均明显低于NC组(P均 < 0.05)。CA组患者基底部3个方向的应变率均明显低于NC组(P均 < 0.05), 但是两组心尖部应变率的差异没有统计学意义。多变量逐步COX分析显示, 肌钙蛋白(HR=1.05, 95%CI: 1.01-1.10, P=0.017)和中间部周向舒张期峰值应变率(HR=6.87, 95%CI: 1.52-31.06, P=0.012)是死亡的强预测因素。
结论: 基于电影序列的CMR-FT获得的应变及应变率参数是一种新的无创性成像标志物, 可用于评估CA的心功能损伤程度以及与HCM心功能的差异, 并为CA患者的全因死亡提供独立的预测信息。
Keywords: cardiac amyloidosis; cardiac magnetic resonance-feature tracking; left ventricle; myocardial strain; myocardial strain rate.