基于CT特征追踪技术评估冠心病患者左心室心肌应变的初步研究

A primary study of evaluating the left ventricular myocardial strain in patients with coronary heart disease by CT feature tracking

目的探讨CT特征追踪(CT-FT)技术评估左心室心肌应变的技术可行性及冠心病患者心肌应变的变化规律。方法回顾性收集南昌大学第二附属医院于2019年4月至2020年10月收治的81例冠心病患者(病变组)和同时间段年龄、性别等相匹配的33名冠状动脉正常者作为对照组。病变组首先按冠状动脉狭窄支数分为单支狭窄组(42例)和多支狭窄组(39例),进行组间左心室整体心肌应变分析;再分别根据左前降支(LAD)、右冠状动脉(RCA)和左回旋支(LCX)血管的狭窄程度将病变分为正常组、轻度狭窄组、中度狭窄组和重度狭窄组,进行相应冠状动脉主要分支节段心肌应变峰值的组间分析。使用后处理软件CVI 42对图像进行分析,获得整体纵向应变峰值(GPLS)、整体环向应变峰值(GPCS)、整体径向应变峰值(GPRS)以及各冠状动脉分支节段的纵向应变峰值(PLS)、环向应变峰值(PCS)、径向应变峰值(PRS)。多组间分析采用单因素方差分析或Kruskal-WallisH检验。结果随着冠状动脉狭窄支数增多,GPLS绝对值逐渐减低,对照组、单支狭窄组及多支狭窄组的GPLS分别为-14.1%±2.7%、-11.5%±2.3%和-8.8%±2.0%,3组间或任意两组间比较差异均有统计学意义(P<0.001);多支狭窄组的GPRS及GPCS绝对值较对照组和单支狭窄组低(P<0.001),单支狭窄组和对照组间GPRS、GPCS的差异无统计学意义(P=0.083、0.118)。LAD、LCX、RCA分支节段的各向应变峰值多组间差异均有统计学意义(P<0.001)。重度狭窄组各分支节段的PRS、PCS、PLS绝对值均显著低于中度狭窄组、轻度狭窄组和正常组(P<0.05),中度狭窄组各分支节段的PLS绝对值均低于轻度狭窄和正常组(P<0.05),余各分支节段的各指标组间差异无统计学意义(P均>0.05)。结论CT-FT技术在评估左心室心肌功能方面具有可行性;且随着冠状动脉狭窄支数及狭窄程度的增加,左心室整体及节段心肌应变参数绝对值呈减低趋势,其中纵向应变较为敏感。

Objective To explore the technical feasibility of CT feature tracking(CT-FT)technique in evaluating left ventricular myocardial strain and evaluate the change of myocardial strain in patients with coronary heart disease.Methods Eighty-one patients with coronary heart disease(lesion group)and 33 patients with normal coronary artery(control group)matched with age and sex were collected retrospectively from the Second Affiliated Hospital of Nanchang University from April 2019 to October 2020.The lesion group was first divided into single vessel stenosis group(42 cases)and multi vessel stenosis group(39 cases)according to the number of coronary artery stenosis branches,and the global myocardial strains of the left ventricle between the groups were analyzed.Lesion site included the left anterior descending branch(LAD),right coronary artery(RCA)and left circumflex branch(LCX),respectively.According to the degree of vascular stenosis,the lesion groups were divided into normal group,mild stenosis group,moderate stenosis group and severe stenosis group.The segmental myocardial strains of the branch segment of LAD,RCA or LCX were analyzed between groups.All CCTA examinations were performed with retrospective electrocardiogram gating.CVI 42 cardiac postprocessing software was used to obtain myocardial strain parameters,including global peak longitudinal strain(GPLS),global peak circumferential strain(GPCS),global peak radial strain(GPRS),and the segmental myocardial strains of the branch segment of LAD,RCA or LCX.The segmental myocardial strains included the peak longitudinal strain(PLS),peak circumferential strain(PCS)and peak radial strain(PRS).One way ANOVA or Kruskal Wallis H test were used for multi group analysis.Results With the increased number of coronary artery stenosis branches,the absolute value of GPLS gradually decreased.The GPLS of the control group,single vessel stenosis group and multi vessel stenosis group were-14.1%±2.7%,-11.5%±2.3%and-8.8%±2.0%,respectively.The difference of GPLS between the 3 groups or any 2 groups was statistically significant(all P<0.001).The absolute values of GPRS and GPRS in multi vessel stenosis group were significantly lower than those in control group and single vessel stenosis group(all P<0.001).There was no significant difference in GPRS or GPRS between single vessel stenosis group and control group(P=0.083,0.118).And there were significant differences in the segmental myocardial strains of the branch segment of LAD,RCA or LCX among 3 groups(P<0.001).In severe stenosis group,the absolute values of PRS,PCS and PLS in LAD,RCA or LCX were significantly lower than those in moderate stenosis group,mild stenosis group and normal group(all P<0.05).In the moderate stenosis group,the absolute value of PLS in each branch segment was lower than that of the mild stenosis and normal group(all P<0.05),and there was no significant difference in any 2 other myocardial strain parameters of each branch(all P>0.05).Conclusions CT-FT technique was feasible to evaluate left ventricular myocardial function.With the increased number or degree of coronary artery stenosis,the global and segmental myocardial strain parameters of left ventricle gradually decreased,and the longitudinal strain was more sensitive.