Nielsen James C, Powell Andrew J, Gauvreau Kimberlee, Marcus Edward N, Prakash Ashwin, Geva Tal
Department of Cardiology, Children's Hospital, Boston, Mass 02115, USA.
Circulation. 2005 Feb 8;111(5):622-8. doi: 10.1161/01.CIR.0000154549.53684.64.
MRI is increasingly used for anatomic assessment of aortic coarctation (CoA), but its ability to predict the transcatheter pressure gradient, considered the reference standard for hemodynamic severity, has not been studied in detail. This study evaluated the ability of MRI to distinguish between mild versus moderate and severe CoA as determined by cardiac catheterization.
The clinical, MRI, and catheterization data of 31 subjects referred for assessment of native or recurrent CoA were reviewed retrospectively. Patients were divided into 2 groups on the basis of peak coarctation gradient by catheterization: <20 mm Hg (n=12) and > or =20 mm Hg (n=19). Patients with cardiac index <2.2 L x min(-1) x m(-2) by catheterization were excluded. By logistic regression analysis, the following variables simultaneously predicted coarctation gradient > or =20 mm Hg: (1) smallest aortic cross-sectional area (adjusted for body surface area) measured by planimetry from gadolinium-enhanced 3D magnetic resonance angiography (OR 1.71 for 10 mm2/m2 decrease, P=0.005) and (2) heart rate-corrected mean flow deceleration in the descending aorta measured by phase-velocity cine MRI (OR 1.68 for 100 mL/s(1.5) increase, P=0.018). For the combination of these variables, a predicted probability >0.38 had 95% sensitivity, 82% specificity, 90% positive and negative predictive values, and an area under the receiver-operator characteristics curve of 0.938. In a subsequent validation study, the prediction model correctly classified 9 of 10 patients, with no false-negatives.
The combination of anatomic and flow data obtained by MRI provides a sensitive and specific test for predicting catheterization gradient > or =20 mm Hg.
磁共振成像（MRI）越来越多地用于主动脉缩窄（CoA）的解剖学评估，但其预测经导管压力梯度（被视为血流动力学严重程度的参考标准）的能力尚未得到详细研究。本研究评估了MRI区分经心导管检查确定的轻度与中度及重度CoA的能力。
回顾性分析了31例因评估原发性或复发性CoA而接受检查的受试者的临床、MRI及心导管检查数据。根据心导管检查测得的缩窄峰值梯度，将患者分为两组：<20 mmHg（n = 12）和≥20 mmHg（n = 19）。排除心导管检查测得心脏指数<2.2 L·min⁻¹·m⁻²的患者。通过逻辑回归分析，以下变量同时预测缩窄梯度≥20 mmHg：（1）通过钆增强三维磁共振血管造影测量的最小主动脉横截面积（根据体表面积校正）（每减少10 mm²/m²，比值比为1.71，P = 0.005），以及（2）通过相速度电影MRI测量的降主动脉心率校正平均血流减速（每增加100 mL/s（1.5），比值比为1.68，P = 0.018）。对于这些变量的组合，预测概率>0.38时，敏感性为95%，特异性为82%，阳性和阴性预测值均为90%，受试者操作特征曲线下面积为0.938。在随后的验证研究中，预测模型正确分类了10例患者中的9例，无假阴性。
MRI获得的解剖学和血流数据的组合为预测导管梯度≥20 mmHg提供了一种敏感且特异的检测方法。
