Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
J Am Soc Echocardiogr. 2012 Dec;25(12):1299-308. doi: 10.1016/j.echo.2012.09.018. Epub 2012 Oct 11.
It has been suggested that the assessment of left ventricular contractile reserve during dobutamine infusion can improve prognostic evaluation for patients with idiopathic dilated cardiomyopathy (DCM). However, the assessment of contractile reserve is often subjective, while three-dimensional (3D) speckle-tracking can quantify three different components of strain simultaneously from all 16 left ventricular segments. The purpose of this study was to investigate the capability of multidirectional deformational indices assessed by 3D speckle-tracking strain to predict cardiac events in patients with DCM. Whether such assessment under dobutamine infusion can enhance this method's predictive capability was also evaluated by comparison with two-dimensional (2D) speckle-tracking.
Sixty-five patients with DCM with a mean ejection fraction of 34 ± 8% (all <45%) were prospectively recruited, and both 3D and 2D speckle-tracking echocardiography was used to measure global circumferential strain (GCS), radial strain, and longitudinal strain at baseline and during dobutamine infusion (20 μg/kg/min). Event-free survival was then tracked over 12 months.
Among all indices of contractile reserve, increase in 3D GCS under dobutamine infusion ≤ 2.71% best predicted cardiovascular events, with 83% sensitivity, 80% specificity, and an area under the curve of 0.874 (P < .001). Furthermore, the area under the curve for increase in 3D GCS was significantly larger than that for both resting 3D GCS and increase in 2D GCS (P < .05 for both). On multivariate Cox analysis, increase in 3D GCS was the only independent predictor of cardiovascular events (hazard ratio, 0.635; P < .001).
Assessment of contractile reserve using 3D GCS has the potential to predict cardiovascular events in patients with DCM and may thus have clinical implications for the management of such patients.
有研究表明，多巴酚丁胺输注时左心室收缩储备的评估可以改善特发性扩张型心肌病（DCM）患者的预后评估。然而，收缩储备的评估往往是主观的，而三维（3D）斑点追踪可以同时从所有 16 个左心室节段量化应变的三个不同成分。本研究旨在探讨 3D 斑点追踪应变的多向变形指数评估预测 DCM 患者心脏事件的能力。通过与二维（2D）斑点追踪比较，评估多巴酚丁胺输注下的这种评估是否可以增强该方法的预测能力。
前瞻性招募了 65 名射血分数平均为 34±8%（均<45%）的 DCM 患者，使用 3D 和 2D 斑点追踪超声心动图测量静息和多巴酚丁胺输注（20μg/kg/min）时的整体周向应变（GCS）、径向应变和纵向应变。然后跟踪 12 个月的无事件生存率。
在所有收缩储备指标中，多巴酚丁胺输注下 3D GCS 的增加≤2.71%预测心血管事件的效果最佳，其敏感性为 83%，特异性为 80%，曲线下面积为 0.874（P<0.001）。此外，3D GCS 增加的曲线下面积明显大于静息 3D GCS 和 2D GCS 增加的曲线下面积（P<0.05）。多变量 Cox 分析显示，3D GCS 的增加是心血管事件的唯一独立预测因子（危险比，0.635；P<0.001）。
使用 3D GCS 评估收缩储备有可能预测 DCM 患者的心血管事件，因此可能对这类患者的管理具有临床意义。
