心脏磁共振可评估急性心肌梗死患者的早期心功能状态.pdf

Cardiac magnetic resonance imaging can evaluate early cardiac function in patients withacute myocardial infarctionLI Miaonan1,DING Siyu1,YAO Zhuoya1,NIU Qilin2,SONG Hongwei2,MA Yichuan2,DING Bin1,HU Sigan1,SHI Xiaojun1,GAODasheng1,WANG Hongju11Department of Cardiovascular Disease,2Department of Radiology,the First Affiliated Hospital of Bengbu Medical College,Bengbu 233004,China摘要：目的 探讨心脏磁共振对急性心肌梗死患者早期心功能状态评估价值。方法 选择2022年6月2022年12月在我科住院并确诊的急性ST段抬高型心肌梗死患者24例，男性22例，女性2例，年龄55.311.3岁。所有患者均在入院后行冠状动脉介入手术，并在术后57 d行心脏磁共振检查。应用电影成像技术分析心功能状态、是否存在反向运动和室壁瘤；组织追踪技术分析心肌各节段的应变能力；延迟强化技术分析心肌梗死部位、梗死面积大小和是否存在微循环障碍。结果 梗死节段心肌应变分析显示：24例患者中，21例患者径向应变下降，18例患者周向应变下降，21例患者纵向应变下降，16例患者三向应变均下降；整体心肌应变分析显示：15例患者径向应变下降，10例患者周向应变下降，20例患者纵向应变下降，9例患者三向应变均下降；梗死节段心肌平均径向应变和周向应变低于整体心肌平均径向应变和周向应变（P0.05）。13例患者出现心肌反向运动；左室射血分数（LVEF）下降者10例；LVEF未下降的14例中，心肌反向运动6例，梗死节段三向心肌应变下降6例，梗死区内微循环障碍7例，NT-proBNP水平升高7例。出现反向运动组患者LVEF、梗死节段心肌和整体心肌平均周向应变、纵向应变均小于未出现反向运动组患者（P0.05）。相关性分析显示：LVEF与心肌整体应变、梗死节段应变和左房射血分数呈正相关关系，与心肌梗死面积、左室收缩末期容积/体表面积比值、NT-proBNP水平和Genisini评分呈负相关关系（P0.05）。二元Logistic回归显示，梗死节段纵向应变的降低可以独立预测患者是否出现心肌反向运动。结论 心脏磁共振技术可以多角度评价心功能状态，对急性心肌梗死患者术后早期心功能评估、治疗和干预，改善患者的预后提供参考依据。关键词：急性心肌梗死；心脏磁共振；心肌应变；心功能Abstract:Objective To explore the value of cardiac magnetic resonance imaging in evaluating early cardiac function inpatients with acute myocardial infarction.Methods The study included 24 patients with acute ST-segment elevationmyocardial infarction who were admitted to our department from June 2022 to December 2022,including 22 male patients and2 female patients,with the age at 55.3 11.3 years old.All patients underwent coronary intervention followed by cardiacmagnetic resonance imaging 5-7 d after the operation.Motion picture imaging was used to analyze cardiac function status,presence or absence of reverse motion and ventricular aneurysm.The strain capacity of each myocardium segment wasanalyzed by tissue tracking technique.The location,size and microcirculation disturbance of myocardial infarction wereanalyzed by delayed enhancement technique.Results Myocardial strain analysis revealed that 21 patients were found to havedecreased radial strain and longitudinal strain among the 24 patients,18 had decreased circumferential strain,and 16 showeda reduction in the three-dimensional myocardial strain.According to the overall analysis of the myocardial strain revealed that15 patients revealed decreased radial strain,10 had decreased circumferential strain,20 had decreased longitudinal strain,and9 showed a reduction in three-dimensional myocardial strain.The mean radial strain and circumferential strain of the MIsegment were significantly lower than that of the average radial strain and circumferential strain of the entire myocardium(P0.05).Moreover,13 patients wereobserved to have myocardial reverse movement.There were 10 and 14 patients with and without decreased left ventricularejection fraction,respectively,among which 6 had myocardial reverse movement,6 showed a decrease in three-dimensionalmyocardial strain in the infarcted segment,7 presented microcirculatory disturbance within the infarct zone,and 7 hadincreased level of NT-proBNP.The mean circumferential and longitudinal strains of left ventricular ejection fraction,infarctsegment myocardium and global myocardium in patients with reverse motion were all smaller than those without reversemotion(P0.05).Correlation analysis indicated that left ventricular ejection fraction was positively correlated with the overallmyocardial strain,myocardial strain in the infarcted segment and left atrial emptying fraction.It was negatively correlatedwith infarct size,left ventricular end-systolic volume/body surface area ratio,NT-proBNP level and Gensini score(P30 min；心电图显示有ST段弓背向上抬高。非ST段抬高型心肌梗死：CK-MB升高超过参考值上限2倍以上；cTnT或cTnI阳性；持续的胸痛，心电图无ST段的抬高，出现一过性或新发的ST段压低或T波倒置、低平或双向。排除标准：既往有心脏手术史、合并频发期前收缩、持续性室性心动过速或其他快速性心律失常；有陈旧性心肌梗死、心脏瓣膜性疾病；严重肝肾功能异常、恶性肿瘤；1月内有感染性疾病；孕期女性；精神异常，配合度差，经训练0.5h后仍难以完成屏气的受试者；钆剂过敏、体内有铁磁性物体、幽闭恐惧症等。1.2 研究方法所有患者入院急诊抽取肘静脉血5 mL于肝素钠抗凝的试管中，送至检验中心进行心肌酶谱、肌钙蛋白、NT-proBNP等生化指标分析。1.2.1 冠状动脉造影 由心内科专业医师操作完成，采用Judkins法行冠状动脉造影，结果判断采用2001年美国ACC/AHA关于心血管疾病诊断和治疗的报道 10。造影提示有明确冠状动脉狭窄70%给予冠状动脉内支架植入术。病变部位植入药物涂层支架，并详细记录患者冠脉造影结果及支架植入过程。支架植入成功标准按照国际惯例，即残余狭窄20%，TIMI3级血流。采用Gensini评分 11 对每支血管病变狭窄程度进行定量计算，由2位熟练的心脏科医师独立评估，计算均值。1.2.2 CMR检查 所有患者术后57 d行CMR检查，机器为我院放射科配备西门子 MAGNETOM Avanto1.5T场强超导磁共振扫描仪。图像分析采用Cvi42（Circle Cardiovascular Imaging,Canada）后处理软件系统进行：扫描图像具备覆盖整个左室短轴位切面，左心室长轴两腔、三腔、四腔心层面。（1）利用软件电影播放功能，测量各房室腔内径；（2）利用软件自带的分析功能，通过半自动方法，手工勾勒出左心室长轴两腔、三腔、四腔心层面收缩末期和舒张末期左心室的心内膜边界、心外膜边界；短轴层面心底段、乳头肌段、心尖段三层收缩末期和舒张末期左心室的心内膜边界、心外膜边界，其中乳头肌划入心腔内；（3）CMR软件将左室心内膜均分为48个特征点并自动追踪心内外膜边界、计算心功能参数和心肌应变指标。1.3 统计学分析采用IBM SPSS26.0统计软件和R语言对数据进行分析处理。符合正态分布的计量资料以均数标准差表示，相关性分析采用Pearson双变量相关性分析和二元Logistic回归。以P0.05为差异有统计学意义。2 结果2.1 患者临床资料24例患者平均心肌梗死面积为（20.6711.73）%；梗死区内微循环障碍者16例；心肌反向运动者13例。左室射血分数（LVEF）下降者10例；LVEF未下降的14例中，心肌反向运动6例，梗死节段三向心肌应变下降6例，梗死区内微循环障碍7例，NT-proBNP水平升高7例（图13）。2.2 心肌应变分析梗死节段心肌平均径向应变为（17.748.95）%，平均周向应变为（-12.18-4.12）%，平均纵向应变为（-10.92-3.99）%；21例患者径向应变下降，18例患者周向应变下降，21例患者纵向应变下降，16例患者三向应变均下降。整体心肌应变分析显示：平均径向应变为（28.0610.42）%，平均周向应变为（-15.69-3.81）%，平均纵向应变为（-11.96-4.30）%；15例患者径向应变下降，10例患者周向应变下降，20例患者纵向应变下降，9例患者三向应变均下降。梗死节段心肌平均径向应变和周向应变低于整体心肌平均径向应变和周向应变（P0.05，表1、图47）。http:/www.j-分子影像学杂志,2023,46(4):620-626 621图1 前壁心肌梗伴微循环障碍2例Fig.1 Anterior myocardial infarction with microcirculation disturbance in 2 cases.图2 下壁心肌梗死伴微循环障碍2例Fig.2 Inferior myocardial infarction with microcirculation disturbance in 2 cases.图3 前壁心肌梗死伴反向运动电影序列图像Fig.3 Anterior myocardial infarction with reverse motion in film sequence images.Myocardial strainRadial strainCircumferential strainLongitudinal strainMyocardial strain in infarct segment7.748.95-12.18-4.12-10.92-3.99Global myocardial strain28.0610.42-15.69-3.81-11.96-4.30P0.0010.0040.392表1 心肌应变分析Tab.1 Myocardial strain analysis(%,MeanSD）分子影像学杂志,2023,46(4):620-626http:/www.j- 622Radial strain peak value(%)Circumferential strain peak value(%)Longitudinal strain peak value(%)105.1 mm(AHA)105.1 mm(AHA)105.1 mm(AHA)图4 前壁心肌梗死心肌应变下降Fig.4 Anterior myocardial infarction myocardial strain decreased.Radial strain peak value(%)Circumferential strain peak value(%)Longitudinal strain peak value(%)96.3 mm(AHA)96.3 mm(AHA)96.3 mm(AHA)图5 下壁心肌梗死心肌应变下降Fig.5 Inferior myocardial infarction myocardial strain decreased.Radial strain peak value(%)Circumferential strain peak value(%)Longitudinal strain peak value(%)101.5 mm(AHA)101.5 mm(AHA)101.5 mm(AHA)图6 前壁心肌梗死应变下降伴反向运动Fig.6 Anterior myocardial infarction decreased myocardial strain with reverse movement.Radial strain peak value(%)Circumferential strain peak value(%)Longitudinal strain peak value(%)90.7 mm(AHA)90.7 mm(AHA)90.7 mm(AHA)图7 下壁心肌梗死应变下降伴反向运动Fig.7 Inferior myocardial infarction decreased myocardial strain with reverse movement.http:/www.j-分子影像学杂志,2023,46(4):620-626 6232.3 心肌反向运动分析反向运动组患者LVEF、梗死节段心肌和整体心肌平均周向应变、纵向应变均小于未出现反向运动组患者（P0.05，表2）。表2 反向运动分析Tab.2 Reverse motion analysis(MeanSD)LAEF:Left atrial ejection fraction:LVEF:Left ventricular ejection fraction;LGE:Late gadoliniumenhancement;LVEDV/BSA:Left ventricular end-diastolic volume/body surface area;LVESV/BSA:Leftventricular end-systolic volume/body surface area;RS:Radial strain;CS:Circumferential strain;LS:Longitudinal strain;TRS:Total radial strain;TCS:Total circumferential strain;TLS:Total longitudinalstrain.IndexAge（year)LVEF(%)LGE(%)LVEDV/BSALVESV/BSARS(%)CS(%)LS(%)TRS(%)TCS(%)TLS(%)LAEF(%)Reverse motion group56.210.643.7715.5122.9012.0572.1912.0542.0319.5614.527.8610.554.099.133.1426.3710.8314.233.9810.253.8553.5413.44Non-reverse motion group54.212.555.2710.0616.7210.9273.3119.4532.8814.4021.549.0014.103.4013.033.9730.0510.0517.432.9013.974.0759.2712.53P0.6730.0410.2020.8870.2010.0570.0300.0160.3970.0330.0330.2922.4 LVEF的影响因素分析LVEF与心肌整体应变、梗死节段应变和左房射血分数呈正相关关系，与心肌梗死面积、左室收缩末期容积/体表面积比值、NP-proBNP水平和Genisini评分呈负相关关系（图8、表3）。2.5 二元Logistic回归分析梗死节段纵向应变的降低可以独立预测患者是否出现心肌反向运动（图9）。3 讨论急性心肌梗死是冠心病中最严重的类型，发病急骤、病情进展快、病死率高。因此早期评估梗死后心脏功能对临床进行危险分层、确定治疗方案和评估临床预后至关重要。CMR技术可通过无创检查完成对心脏结构、功能等检查与评价，不仅是临床检测梗死瘢痕心肌的金标准，也是心肌功能评估的金标准 12-16，尤其是心脏磁共振组织追踪技术的应用 17-18，可以早期评估心脏结构和功能的异常，特别对射血分数保留的心衰患者，可定量分析收缩、舒张功能受损程度，达到早期诊断、预后判断的作用。心肌应变是指心肌在张力作用下的形变能力 19-21，心内膜下心肌从心底到心尖纵向排列，中层心肌纤维环图8 相关性分析Fig.8 Correlation analysis.分子影像学杂志,2023,46(4):620-626http:/www.j- 624周排列，心外膜下层心肌从心尖到心底斜向排列，由于结构复杂，收缩期左室不同方向的形变，造成纵向和周向缩短，径向增厚，并扭转约15 22-24。有学者通过心脏磁共振组织追踪技术对300多例STEMI患者进行随访研究发现，在对基线和CMR变量进行校正后，纵向应变可预测心脏不良事件的发生 25。已有研究发现，心肌应变指数用于心肌功能评估相较于LVEF更为敏感，可准确反映心脏收缩期功能 26。本研究结果发现梗死节段心肌无论是平均径向应变、周向应变还是纵向应变都低于正常心肌应变的（径向应变正常范围为30%40%、周向应变和纵向应变为-15%-20%），且其中16例患者三向应变均明显下降；对整体心肌应变分析也有15例患IndexAgeLGE(%)LVEDV/BSALVESV/BSARS(%)CS(%)LS(%)TRS(%)TCS(%)TLS(%)LAEF(%)NT-proBNPGensiniR-0.237-0.620-0.402-0.8360.6740.7220.7850.7480.9000.7360.754-0.702-0.429P0.2640.0010.0510.0010.0010.0010.0010.0010.0010.0010.0010.0010.036表3 LVEF相关性分析Tab.3 LVEF correlation analysisParadoxical motion(0-No,1-Yes)1.000.750.500.250.005101520Longitudinal strain of infarcted lesion(%)Logistic regression model图9 回归分析Fig.9 Regression analysis.者径向应变下降，10例患者周向应变下降，20例患者纵向应变下降，9例患者三向应变均下降，可见急性心肌梗死患者绝大多数早期心肌应变能力已经受到损伤。本研究还发现在LVEF正常的14例患者中，6例已经出现了心肌反向运动，6例出现了梗死节段三向心肌应变下降，7例出现梗死区内微循环障碍，7例出现NT-proBNP水平升高。可见对于LVEF保留的患者，约半数心肌已经发生了应变能力的下降和反向运动，此时如果不及时的进行干预治疗，最终会导致室壁瘤的形成和不可逆的心力衰竭。本研究对LVEF的相关性分析发现，LVEF与急性心肌梗死患者心肌整体应变、梗死节段应变、左房射血分数呈正相关关系，与心肌梗死面积、左室收缩末期容积/体表面积比值、NT-proBNP水平和Genisini评分呈负相关关系。二元Logistic回归显示，梗死节段纵向应变的降低可以独立预测患者是否出现心肌反向运动。说明心肌梗死后心功能的变化评价指标是多样的，不但要看传统的LVEF、NT-proBNP，心肌的应变能力、梗死面积大小、血管狭窄程度、反向运动的出现等都是评价患者心功能状态的重要指标 27-30。综上所述，心脏磁共振技术可以多角度评价心功能状态，对急性心肌梗死患者术后早期心功能评估、早期进行治疗和干预，改善患者的预后提供参考依据30。但本研究例数较少，且为单中心研究，后续将继续进行大样本的研究和进一步随访工作。http:/www.j-分子影像学杂志,2023,46(4):620-626 625参考文献：1 中国心血管健康与疾病报告 编写组.中国心血管健康与疾病报告2021 概述 J .中国心血管病研究,2022(7):577-96.2 Leiner T,Bogaert J,Friedrich MG,et al.SCMR Position Paper(2020)onclinicalindicationsforcardiovascularmagneticresonance J .J Cardiovasc Magn Reson,2020,22(1):76.3 Avard E,Shiri I,Hajianfar G,et al.Non-contrast Cine CardiacMagnetic Resonance image radiomics features and machinelearning 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