Abstract
Background: Mitral valve area (MVA) measurement by three-dimensional transesophageal echocardiography (3D-TEE) has a crucial role in the evaluation of mitral stenosis (MS) severity. Three-dimensional direct (3D-direct) planimetry has been proposed as a new technique to measure mitral valve area. This study aimed to compare the 3D-direct mitral valve planimetry to conventional three-dimensional multiplanar reconstruction (3D-MPR) in severe mitral stenosis (MS) using 3D-TEE.Methods: 149 patients with severe MS who were referred for percutaneous transmitral commissurotomy (PTMC), prospectively recruited. All patients underwent 2D transthoracic echocardiography (2D-TTE) and 3D-TEE in a single session before PTMC. During 2D-TTE planimetry, pressure half time (PHT), and proximal isovelocity surface area (PISA) were applied to measure the MVA. Transmitral mean pressure gradient (MPG) was measured. During 3D-TEE, MVA planimetry was carried out with both 3D-direct and 3D-MPR methods. 3D-direct was applied from both atrial and ventricular views. The consistency of MVA measurements with 3D-direct, 3D-MPR, and 2D-TTE methods was statistically investigated.Results: Our sample consisted of 109 (73.2%) women and 40 (26.8%) men. The mean age was 51.75 ± 9.81 years. The agreement between 3D-direct and 3D-MPR planimetry was significant and moderate (0.99 ± 0.29 cm2 vs. 1.12 ± 0.26 cm2, Intraclass Correlation = 0.716, p value =0.001).The accuracy of the 3D-direct method reduced significantly compared to the MPR method at MVA > 1.5 cm2. The maximum difference between two methods was observed in cases with MVAs larger than 1.5 cm2. MVA measured with the 3D-MPR method was significantly correlated with a 2D-TTE method, with a moderate agreement (Intraclass Correlation = 0.644, p value = 0.001). Also, 2D-TTE and 3D-direct TEE techniques yielded significantly consistent measurements of the MVA (1.06 ± 0.026 cm2 vs. 0.99 ± 0.29 cm2, Intraclass Correlation = 0.787, p value = 0.001); however, with a slight overestimation of the MVA by the former with a net difference of 0.06 ± 0.013 cm2. Mitral valve pressure gradient (MPG) had no significant correlation with planimetry results. A significant inverse correlation was seen between the MVA and pulmonary arterial systolic pressure.Conclusion: 3D-direct planimetry has an acceptable agreement with 3D-MPR planimetry at MVA less than 1.5 cm2, but their correlation decreases significantly at MVA above 1.5 cm2. 3D-direct planimetry underestimates MVA compared to 3D-MPR, especially at MVA above 1.5 cm2. The 2D-TTE planimetry has generally acceptable accuracy, but its correlation to the 3D-TEE methods is significantly reduced in cases with moderate to severe MS (i.e. MVA> 1.0cm2).
SEVERE MITRAL STENOSIS;