[Value of left ventricular myocardial strain derived from cardiac magnetic resonance tissue tracking on differentiating constrictive pericarditis from restrictive cardiomyopathy].

Objective: To compare left ventricular myocardial mechanics detected by cardiac magnetic resonance tissue tracking(CMR-TT) between patients with constrictive pericarditis(CP) and restrictive cardiomyopathy(RCM),and see if those can be used to differentiate CP from RCM patients. Methods: A total of 23 patients with CP, 20 patients with RCM, who hospitalized in Beijing Anzhen Hospital from January 2014 to April 2019 were included in this study and 25 healthy subjects served as control group, all subjects underwent cardiac magnetic resonance examination. Myocardial mechanics were evaluated by 2-dimensional(2D) and 3-dimensional(3D) CMR-TT in terms of global longitudinal strain(GLS), circumferential strain(GCS), radial strain(GRS) and the lateral wall strain to septal wall strain ratio(lateral/septal ratio) of basal, mid-cavity and apical. The diagnostic area under the receiver operating characteristic curve (ROC) was evaluated for differentiating CP from RCM. Results: Age, sex and heart rate were similar between CP and RCM patients(all P>0.05). 2D-GLS, 3D-GLS, GCS and GRS in CP and RCM groups were significantly lower than those in normal control group(all P<0.05).3D-GLS value was significantly lower in RCM patients than in CP patients(P<0.05), the area under the curve (AUC)=0.787(sensitivity 80%, specificity 78%). 3D-GCS was significantly lower in CP group than in RCM group(P<0.05), the AUC=0.737(sensitivity 80%, specificity 65%). However, there was no significant difference between CP and RCM in 3D-GRS(P>0.05). Compared with RCM, the circumferential and radial lateral/septal ratios of the basal were significantly lower in CP group than in RCM group(both P<0.05), AUC=0.737(sensitivity 70%, specificity 83%) and 0.737 (sensitivity 60%, specificity 87%), respectively. The left ventricular myocardial mechanics strain curve of the CP,RCM and normal control were different. The CP patients presented as " rapidly down-a platform" form, the RCM presented as "slowly down" form, and normal control presented as "rapidly down" form. Conclusion: Evaluating the differences in the diastolic process of left ventricular myocardium and left ventricular myocardial mechanics strain curve is helpful to differentiate CP from RCM patients.目的： 评估心脏磁共振组织追踪技术对于缩窄性心包炎（CP）与限制性心肌病（RCM）鉴别诊断的价值。 方法： 回顾性入选2014年1月至2019年4月在北京安贞医院确诊为CP的患者（CP组）和RCM的患者（RCM组），同时选取同期健康体检的无高血压、冠心病、心肌疾病、心律失常等心肺疾病病史，心电图和超声心动图检查未发现异常，心脏磁共振（CMR）检查基本正常，且性别、年龄与CP组和RCM组患者匹配者作为对照（正常对照组）。通过电子病历库系统收集入选者的一般临床资料、CMR检查结果等。应用心脏磁共振组织追踪（CMR-TT）技术计算入选者左心室二维及三维整体纵向应变（GLS）、周向应变（GCS）、径向应变（GRS），以及基底部、乳头肌层、心尖部左心室外侧壁/间隔壁应变比值，并描绘左心室心肌应变曲线。采用受试者工作特征（ROC）曲线评估CMR-TT技术指标对于CP和RCM鉴别诊断的价值。 结果： 本研究共入选CP患者23例，年龄（42.1±16.6）岁，其中男性13例；RCM患者20例，年龄（51.1±20.7）岁，其中男性16例。同时正常对照组入选25人，年龄（43.4±9.7）岁，其中男性12例。CP组与RCM组患者的年龄、性别构成、心率差异均无统计学意义（P均>0.05）。CMR-TT技术分析结果显示，CP组和RCM组患者二维和三维GLS、GCS、GRS均低于正常对照组（P均<0.05）。RCM组患者二维和三维GLS均低于CP组（P均<0.05），而GCS则高于CP组（P均<0.05）。RCM组患者二维GRS低于CP组（P<0.05），而三维GRS两组间差异无统计学意义（P>0.05）。CP组与RCM组患者基底部、乳头肌层面、心尖部纵向左心室外侧壁/间隔壁应变比值差异均无统计学意义（P均>0.05）。CP组患者基底部周向左心室外侧壁/间隔壁应变比值小于RCM组（P<0.05），而乳头肌层、心尖部两组间差异均无统计学意义（P均>0.05）。CP组患者基底部、乳头肌层径向左心室外侧壁/间隔壁应变比值均低于RCM组（P均<0.05），而心尖部两组间差异则无统计学意义（P>0.05）。三组患者左心室应变曲线下降的趋势不同，CP组患者呈"陡降-平台型"，RCM组患者呈"缓降型"，正常对照组呈"陡降型"。ROC曲线分析结果显示，三维GLS（AUC=0.787，P=0.001）鉴别CP和RCM的价值优于二维GLS（AUC=0.723，P=0.013），三维GLS最佳截断值为-9.29%，低于-9.29%倾向于RCM，反之则倾向于CP，敏感度为80%，特异度为78%。三维GCS（AUC=0.737，P=0.008）鉴别CP和RCM的价值优于二维GCS（AUC=0.726，P=0.011），三维GCS最佳截断值为-18.3%，低于-18.3%倾向于CP，反之则倾向于RCM，敏感度为80%，特异度为65%。基底部周向和径向左心室外侧壁/间隔壁应变比值对CP和RCM具有较好的鉴别诊断价值（分别为，AUC=0.737，P=0.008；AUC=0.737，P=0.008）。基底部周向左心室外侧壁/间隔壁应变比值最佳截断值为1.17，低于1.17倾向于CP，反之则倾向于RCM，敏感性度为70%，特异度为83%；基底部径向左心室外侧壁/间隔壁应变比值最佳截断值为1.39，低于1.39倾向于CP，反之则倾向于RCM，敏感度为60%，特异度为87%。 结论： 通过CMR-TT瞬时定量检测各部分心肌舒缩程度，发现心肌应变的差异，有助于CP与RCM的鉴别诊断。.