Olmos L, Salazar G, Barbetseas J, Quiñones M A, Zoghbi W A
Department of Medicine, Baylor College of Medicine, The Methodist Hospital, Houston, Texas 77030, USA.
Am J Cardiol. 1999 Jan 15;83(2):199-205. doi: 10.1016/s0002-9149(98)00824-8.
To identify the transthoracic echo-Doppler (TTE) variables most predictive of significant mitral regurgitation (MR) of mechanical prosthetic valves, TTE and trans-esophageal echo (TEE) studies were independently reviewed in 57 patients (mean age [+/-SD] 59+/-12.5 years) undergoing both studies within 2+/-3 days. Several 2-dimensional and Doppler hemodynamic variables from the TTE studies were derived. Prosthetic MR was significant (moderate or severe) by TEE in 20 patients, whereas mild or no MR was seen in 37 patients. The best univariate predictors of significant MR by TTE were peak velocity of mitral inflow, mean gradient, tricuspid regurgitation velocity, isovolumic relaxation time, and ratio of time velocity integral of mitral inflow to time velocity integral in the left ventricular outflow (TVI(MV)/TVI(LVO)). Peak mitral velocity and TVI(MV)/TVI(LVO) were the best predictors of significant MR and performed similarly (area under the receiver-operating characteristic curve: 0.97 for both). A peak velocity of > or =1.9 m/s was 90% sensitive and 89% specific for significant prosthetic MR, whereas a TVI(MV)/TVI(LVO) > or =2.5 had a sensitivity and specificity of 89% and 91%, respectively. A decision tree was constructed to assess the conditional probabilities of having significant MR given all the possible outcomes of the 2 best predictors. None of the patients with peak velocity < 1.9 m/s and TVI(MV)/TVI(LVO) <2.5 by TTE had significant MR. Conversely, all patients with peak velocity > or =1.9 m/s and TVI(MV)/TVI(LVO) > or =2.5 had significant MR. The use of more complex algorithms did not further improve the results. Thus, measurements of hemodynamic Doppler variables on TTE examination can accurately identify a large number of patients without significant prosthetic MR, thereby reducing the need for further investigation with TEE.
为了确定经胸超声多普勒（TTE）中最能预测机械瓣膜严重二尖瓣反流（MR）的变量，我们对57例患者（平均年龄[±标准差]59±12.5岁）的TTE和经食管超声（TEE）研究进行了独立回顾，这些患者在2±3天内接受了这两项检查。从TTE研究中得出了几个二维和多普勒血流动力学变量。TEE显示20例患者存在严重（中度或重度）人工瓣膜MR，而37例患者为轻度或无MR。TTE预测严重MR的最佳单变量指标为二尖瓣流入峰值速度、平均压差、三尖瓣反流速度、等容舒张时间以及二尖瓣流入时间速度积分与左心室流出道时间速度积分之比（TVI(MV)/TVI(LVO)）。二尖瓣峰值速度和TVI(MV)/TVI(LVO)是严重MR的最佳预测指标，表现相似（受试者工作特征曲线下面积：两者均为0.97）。峰值速度≥1.9 m/s对严重人工瓣膜MR的敏感性为90%，特异性为89%，而TVI(MV)/TVI(LVO)≥2.5的敏感性和特异性分别为89%和91%。构建了一个决策树来评估在两个最佳预测指标的所有可能结果下发生严重MR的条件概率。TTE检查中峰值速度<1.9 m/s且TVI(MV)/TVI(LVO)<2.5的患者均无严重MR。相反，峰值速度≥1.9 m/s且TVI(MV)/TVI(LVO)≥2.5的所有患者均有严重MR。使用更复杂的算法并未进一步改善结果。因此，TTE检查中的血流动力学多普勒变量测量可准确识别大量无严重人工瓣膜MR的患者，从而减少进一步进行TEE检查的必要性。
