Discrepancies between cardiovascular magnetic resonance and Doppler echocardiography in the measurement of transvalvular gradient in aortic stenosis: the effect of flow vorticity
Discrepancies between cardiovascular magnetic resonance and Doppler echocardiography in the measurement of transvalvular gradient in aortic stenosis: the effect of flow vorticity
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DOI：
10.1186/1532-429x-15-84
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发表时间：
2013-09-20
影响因子：
6.4
通讯作者：
Larose, Eric
中科院分区：
文献类型：
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作者：
Garcia, Julio;Capoulade, Romain;Larose, Eric
背景：瓣膜有效瓣口面积EOA和跨瓣膜平均压差(MPG)是评价主动脉瓣狭窄(AS)严重程度最常用的参数。然而，心血管磁共振(CMR)测量的MPG与经胸多普勒超声心动图(TTE)测量的MPG可能不同。本研究的目的是：1)确定导致AS患者CMR和TTE测量MPG差异的因素；2)探讨气流涡度对CMR评估AS严重程度的影响；3)评价两种协调CMR/TTE测量MPG差异的模型。方法：8名健康受试者和60例AS患者接受TTE和CMR检查。根据CMR计算了Strouhal数(ST)、能量损失(EL)和涡度。对两种校正模型进行评估：1)基于Gorlin方程(MPG(CMR-Gorlin))；2)基于多元回归模型(MPG(CMR-Predicted))。结果：MPG(CMR预测)低估了MPG(TTE)(偏差=-6.5 mm Hg，符合范围为-18.3~5.2 mm Hg)。在多元回归分析中，ST(p=0.002)、EL(p=0.001)和平均收缩期涡度(p<；0.001)与CMR和TTE之间较大的MPG差异独立相关。MPG(CMR-Gorlin)和MPG(TTE)的相关性和一致性为r=0.7，偏倚=-2.8 mm Hg，一致范围为-18.4~12.9 mm Hg。MPG(CMR-Predicted)模型与MPG(TTE)的相关性和一致性较好(r=0.82；偏差=0.5 mm Hg，符合范围为-9.1~10.2 mm Hg)。结论：流动涡度是造成CMR和TTE的MPG差异的主要因素之一。
Background: Valve effective orifice area EOA and transvalvular mean pressure gradient (MPG) are the most frequently used parameters to assess aortic stenosis (AS) severity. However, MPG measured by cardiovascular magnetic resonance (CMR) may differ from the one measured by transthoracic Doppler-echocardiography (TTE). The objectives of this study were: 1) to identify the factors responsible for the MPG measurement discrepancies by CMR versus TTE in AS patients; 2) to investigate the effect of flow vorticity on AS severity assessment by CMR; and 3) to evaluate two models reconciling MPG discrepancies between CMR/TTE measurements.Methods: Eight healthy subjects and 60 patients with AS underwent TTE and CMR. Strouhal number (St), energy loss (EL), and vorticity were computed from CMR. Two correction models were evaluated: 1) based on the Gorlin equation (MPG(CMR-Gorlin)); 2) based on a multivariate regression model (MPG(CMR-Predicted)).Results: MPG(CMR) underestimated MPG(TTE) (bias = -6.5 mmHg, limits of agreement from -18.3 to 5.2 mmHg). On multivariate regression analysis, St (p = 0.002), EL (p = 0.001), and mean systolic vorticity (p < 0.001) were independently associated with larger MPG discrepancies between CMR and TTE. MPG(CMR-Gorlin) and MPG(TTE) correlation and agreement were r = 0.7; bias = -2.8 mmHg, limits of agreement from -18.4 to 12.9 mmHg. MPG(CMR-Predicted) model showed better correlation and agreement with MPG(TTE) (r = 0.82; bias = 0.5 mmHg, limits of agreement from -9.1 to 10.2 mmHg) than measured MPG(CMR) and MPG(CMR-Gorlin).Conclusion: Flow vorticity is one of the main factors responsible for MPG discrepancies between CMR and TTE.