Usefulness of transthoracic echocardiography in detecting significant prosthetic mitral valve regurgitation

To identify the transthoracic echo-Doppler (TTE) variables most predictive of significant mitral regurgitation (MR) of mechanical prosthetic valves, T TE and trans-esophageal echo (TEE) studies were independently reviewed in 5 7 patients (mean age [+/- SD] 59 +/- 12.5 years) undergoing both studies wi thin 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 pati ents. The best univariate predictors of significant MR by TIE were peak vel ocity of mitral inflow, mean gradient, tricuspid regurgitation velocity, is ovolumic relaxation time, and ratio of time velocity integral of mitral inf low to time velocity integral in the left ventricular outflow (TVIMV/TVILVO ). Peak mitral velocity and TVIMV/TVILVO were the best predictors of signif icant MR and performed similarly (area under the receiver-operating charact eristic curve: 0.97 for both). A peak velocity of greater than or equal to 1.9 m/s was 90% sensitive and 89% specific for significant prosthetic MR, w hereas a TVIMV/TVILVO greater than or equal to 2.5 had a sensitivity and sp ecificity 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 TVIMV/TVILVO <2.5 by TTE had significant MR. Convers ely, all patients with peak velocity greater than or equal to 1.9 m/s and T VIMV/TVILVO greater than or equal to 2.5 had significant MR. The use of mor e complex algorithms did not further improve the results. Thus, measurement s of hemodynamic Doppler variables on TTE examination can accurately identi fy a large number of patients without significant prosthetic MR, thereby re ducing the need for further investigation with TEE, (C) 1999 by Excerpta Me dico, Inc.