斑点追踪成像联合室壁运动评分预测急性心肌梗死患者左心室重构的随访研究

Prediction of left ventricular remodeling in patients with acute myocardial infarction by speckle tracking imaging with wall motion score index：a clinical follow-up study

目的应用斑点追踪成像（STI）技术联合室壁运动评分（wMSI）分析心肌梗死后心肌节段性运动障碍与左室重构的关系，探讨STI在预测急性心肌梗死患者左室重构中的价值。方法选取首次发作急性心肌梗死的患者83例，在发病24h内及6个月随访时进行超声心动图检查，采集长轴及短轴的各标准切面图像存盘，通过EchoPac工作站读取各节段WMSI分值，并分析得出STI纵向（GLS）、径向（GRs）及环向（Gcs）应变参数定量数据。以左室舒张末期容积在随访时与发生AMI时比较变化率（ALVEDV％）≥20％定义为左室重构，将患者分为左室重构组与非重构组。通过WMIS分值≥2选取存在运动障碍的心肌节段，并计算这些节段纵向应变（LS—WMSI）、径向应变（RS—WMSI）及环向应变（CS—WMSI）均值。结果27例急性心肌梗死患者在6个月随访时发生了左室重构。两组整体STI参数差异均有统计学意义（P均〈0．05），通过WMSI选取的存在运动障碍节段STI参数差异具有统计学意义（P均〈0．001）。WMSI选取节段STI参数均与△LVEDV％具有相关性，其中CSWMSI相关性较好（r=0．716，P〈0．001）。WMSI选取的存在运动障碍节段STI参数的敏感性、特异性及曲线下面积相对较好，其中CS—WMSI的诊断效率相对较高（敏感性92．6％，特异性87．5％，曲线下面积0．9563，截值-5．5％）。结论STI技术能够准确预测急性心肌梗死患者的左室重构。存在运动障碍节段STI参数尤其是CS—WMSI的诊断效率相对较好，提示心肌梗死后环向运动功能的受损与左室重构具有密切关系。

Objective To explore the prognostic value of speckle tracking imaging （STI） for left ventricular remodeling（LVR） in acute myocardial infarction （AMI） patients with the analysis of the relation between regional wall motion abnormality after AMI and LVR by STI in association with wall motion score index （WMSI）. Methods Eighty-three patients with first onset AMI were enrolled from January 2012 to May 2015 and underwent echocardiography within 24 h of the onset and at 6-month follow-up. LVR was defined as more than 20% of the percentage change of left ventricular end-diastolic volume （ALVEDV%） from baseline to 6-month follow-up （divided as LVR and non-LVR group）. Standard long-axis and short- axis views were stored and analyzed for longitudinal （LS）, radial （RS） and circumferential （CS） strain of STI metrics as well as scores of WMSI. Segments of WMSI≥2 were selected and calculated for the mean values of LS （LS_WMSI）,RS （RS_WMSI） and CS （CS_WMSI）. Results LVR occurred in twenty-seven AMI patients at 6-month follow-up. No difference has shown for demographics, electrocardiogram, lab tests, coronary angiography as well as the measurements of two-dimensional echocardiography between the two groups from baseline, while all STI metrics had statistical difference when the comparisons （ P 〈0.05, all）, especially the WMSI selected STI metrics （ P 〈0. 001, all）. Linear regression analysis demonstrated that CS_WMSI （ r = 0. 716, P 〈0. 001） was best correlated to ALVEDV% among all STI metrics and also the best predictor of LVR by receive operator curve analysis （sensitivity of 92.6%, specificity of 87.5% and area under the curve of 0. 9563）. Conclusions Baseline STI metrics can precisely predict LVR at 6-monthfollow up. Among the STI metrics, CS_WMSI has shown preferable predictive and diagnostic value, which indicates that the impairment of segmental circumferential wall motion is closely correlated to LVR after myocardial infarction.