Henn Matthew C, Cupps Brian P, Kar Julia, Kulshrestha Kevin, Koerner Danielle, Braverman Alan C, Pasque Michael K
Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Mo.
Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St Louis, Mo.
J Thorac Cardiovasc Surg. 2015 Jul;150(1):240-6. doi: 10.1016/j.jtcvs.2015.03.049. Epub 2015 Apr 1.
When significant coronary lesions are identified by angiography, regional left ventricular (LV) contractile function often plays a role in determining candidacy for revascularization. To improve on current subjective and nonquantitative metrics of regional LV function, we tested a z-score "normalization" of regional strain information quantified from clinically acquired high-resolution LV geometric datasets.
Test subjects (n = 120) underwent cardiac MRI with multiple 3-dimensional strain parameters calculated from tissue tag-plane displacement data. Sixty healthy volunteers contributed strain parameter data at each of 15,300 LV grid points, to form a normal human strain database. Point-specific database comparisons were made in 60 patients who had documented coronary artery disease (CAD), by angiography. Patient-specific, color-coded 3-dimensional LV maps of z-score-normalized contractile function were generated.
Blinded clinical review indicated that 55% (33 of 60) of the patients with CAD had significant regional contractile abnormalities by 1 of 3 "gold-standard" criteria: (1) Q waves on electrocardiography (ECG); (2) infarct on radionuclide single-photon emission computed tomography (SPECT); or (3) akinesia or dyskinesia on echocardiography. Consistency among all gold-standard metrics was found for only 19% (6 of 31) of patients with CAD who had ≥2 available metrics. Blinded MRI-based, multiparametric, strain z-score localization of contractile abnormalities was accurate in 89% (ECG), 97% (SPECT), and 95% (echocardiography).
Nonsubjective normalization of regional LV contractile function by z-score calculation from a normal human strain database can localize and quantitatively display regional wall motion abnormalities in patients with CAD. This high-resolution localization of regional wall motion abnormalities may help improve the accuracy of therapeutic intervention in patients who have CAD.
当通过血管造影术确定存在显著冠状动脉病变时，局部左心室（LV）收缩功能通常在决定血运重建的候选资格方面发挥作用。为了改进当前局部LV功能的主观和非定量指标，我们测试了一种基于z分数的“标准化”方法，该方法用于对从临床获取的高分辨率LV几何数据集中量化的局部应变信息进行处理。
测试对象（n = 120）接受了心脏磁共振成像检查，并根据组织标记平面位移数据计算了多个三维应变参数。60名健康志愿者在15300个LV网格点中的每一个点上贡献了应变参数数据，以形成一个正常人体应变数据库。通过血管造影术对60例有冠状动脉疾病（CAD）记录的患者进行了特定点的数据库比较。生成了患者特异性的、颜色编码的z分数标准化收缩功能的三维LV图。
盲法临床评估表明，55%（60例中的33例）的CAD患者根据以下3项“金标准”中的1项存在显著的局部收缩异常：（1）心电图（ECG）上的Q波；（2）放射性核素单光子发射计算机断层扫描（SPECT）上的梗死灶；或（3）超声心动图上的运动减弱或运动障碍。在有≥2项可用指标的CAD患者中，仅19%（31例中的6例）的患者在所有金标准指标之间存在一致性。基于MRI的盲法、多参数、应变z分数对收缩异常的定位在89%（ECG）、97%（SPECT）和95%（超声心动图）的情况下是准确的。
通过从正常人体应变数据库计算z分数对局部LV收缩功能进行非主观标准化，可以定位并定量显示CAD患者的局部壁运动异常。这种对局部壁运动异常的高分辨率定位可能有助于提高CAD患者治疗干预的准确性。
