心脏磁共振T1 mapping技术评估AS患者心肌纤维化程度及预后的价值

Value of T1 mapping technology in cardiac magnetic resonance for assessing the degree of myocardial fibrosis and prognosis in patients with aortic stenosis

目的 探讨心脏磁共振(CMR)中纵向弛豫时间定量(T1 mapping)技术评估主动脉瓣狭窄(AS)患者心肌纤维化程度及预后的价值。方法 选取2021年3月—2022年8月在泸州市中医医院进行CMR成像检查的51例AS患者纳入观察组。另同期选取在本院进行CMR成像检查的49例无胸闷、心悸、心绞痛等常见心血管疾病症状,且心电图检查正常的健康人群为对照组。对比观察组、对照组左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)、每搏输出量(SV)、左心室射血分数(LVEF)、左心室舒张末期容积指数(LVESVI)、左心室收缩末期容积指数(LVEDVI)、心肌质量、增强前T1、增强后T1、细胞外部积分数(ECV);比较观察组中不同狭窄程度AS患者增强前T1、增强后T1、ECV;采用Pearson相关分析观察组患者增强前T1、增强后T1及ECV与LVEF的关系;采用多元logistic回归分析影响AS预后的单因素、多因素;对比增强前T1、增强后T1、ECV单一及联合检测对AS的诊断效果。结果 观察组患者LVEF、SV均高于对照组研究对象,心肌质量大于对照组研究对象(P<0.05)。观察组患者增强前T1、ECV高于对照组,增强后T1低于对照组,差异均有统计学意义(P<0.05)。不同狭窄程度AS患者增强前T1、增强后T1、ECV比较:重度狭窄组>中度狭窄组>轻度狭窄组(P<0.05)。Pearson相关分析显示,增强前T1、ECV与LVEF均呈负相关(r=-0.371、-0.428;P<0.05),而增强后T1与LVEF呈正相关(r=0.495,P<0.05)。经随访,发现有9例患者预后不良,42例患者预后良好;经过多元logistic回归分析显示,LVEF、SV、心肌质量、ECV、增强前T1、增强后T1是AS预后的独立影响因素(P<0.05)。ROC结果显示,三参数联合诊断AS的AUC、敏感度、特异度分别为0.890、92.98%、89.18%,明显高于增强前T1、增强后T1、ECV的单独预测。结论 CMR T1技术可用于评估AS患者的心肌纤维化程度及预后,值得推广应用。

Objective To explore the value of longitudinal relaxation time quantification(T1 mapping)technology in cardiac magnetic resonance(CMR)for assessing the degree of myocardial fibrosis and prognosis in patients with aortic stenosis(AS).Methods Fifty-one AS patients who underwent CMR imaging at Luzhou Traditional Chinese Medicine Hospital from March 2021 to August 2022 were included in the observation group.Additionally,49 healthy individuals without common cardiovascular symptoms such as chest tightness,palpitations,and angina,and with normal electrocardiogram findings,who underwent CMR imaging at the same period in our hospital,were selected as the control group.The left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),stroke volume(SV),left ventricular ejection fraction(LVEF),left ventricular end-systolic volume index(LVESVI),left ventricular end-diastolic volume index(LVEDVI),myocardial mass,pre-contrast T1,post-contrast T1,and extracellular volume(ECV)were compared between the observation and control groups.The pre-contrast T1,post-contrast T1,and ECV of AS patients with different degrees of stenosis in the observation group were also compared.Pearson correlation analysis was used to assess the relationship between pre-contrast T1,post-contrast T1,and ECV with LVEF.Univariate and multivariate logistic regression analyses were performed to identify factors affecting the prognosis of AS.The diagnostic efficacy of pre-contrast T1,post-contrast T1,and ECV alone or in combination for AS was compared.Results The LVEF and SV in the observation group were significantly higher than those in the control group,and the myocardial mass was significantly greater than that in the control group(P<0.05).The pre-contrast T1 and ECV in the observation group were significantly higher than those in the control group,while the post-contrast T1 was significantly lower than that in the control group(P<0.05).Comparison of precontrast T1,post-contrast T1,and ECV among AS patients with different degrees of stenosis:severe stenosis group>mod-erate stenosis group>mild stenosis group(P<0.05).Pearson correlation analysis showed that pre-contrast T1 and ECV were negatively correlated with LVEF(r=-0.371,-0.428;P<0.05),while post-contrast T1 was positively correlated with LVEF(r=0.495,P<0.05).During follow-up,9 patients had poor prognosis,and 42 patients had good prognosis.Multivariate logistic regression analysis indicated that LVEF,SV,myocardial mass,ECV,pre-contrast T1,and post-contrast T1 were independent factors affecting the prognosis of AS(P<0.05).The ROC results indicated that the AUC,sensitivity,and specificity of the three parameters combined for diagnosing AS were 0.890,92.98%,and 89.18%,respectively,which were significantly higher than those of pre-contrast T1,post-contrast T1,and ECV alone.Conclusion T1 mapping technology in CMR can reflect the degree of myocardial fibrosis and prognosis in AS,holding promise for a wider application.