Assessment of mitral stenosis: role of real-time 3D TEE

Measurement of mitral valve area in patients with mitral stenosis by 3D echocardiography: A comparison between direct planimetry on 3D zoom and 3D quantification

BACKGROUND

Measurement of the mitral valve area (MVA) in patients with mitral stenosis (MS) by 3D echocardiography (3DE) is usually done via 3D quantification (3DQ). The present study on patients with severe MS sought to evaluate the agreement regarding the MVA measurement between 3DQ and direct planimetry on 3D zoom and also between 3DE and 2DE.

METHODS

Twenty-six patients (22 female, mean age:34.5 ± 14.0 years) with severe MS diagnosed by 2D transthoracic echocardiography(2DTTE) underwent 3D transesophageal echocardiography (3DTEE). Direct planimetry, the pressure half-time (PTH), and the continuity equation(CE) constituted 3 conventional 2DTTE methods, and 3DQ and direct planimetry on 3D zoom comprised two 3DTEE methods applied for the MVA measurement. Agreement between the 2D and 3D methods was assessed using the Bland-Altman plot and measuring the intra-class correlation coefficient (ICC).

RESULTS

The mean MVA measured by 3DQ was significantly larger than that derived by direct planimetry on 3D zoom (0.935 ± 0.23 cm² vs 0.846 ± 0.22 cm² , respectively; P = 0.026). The agreement between 3DQ and 3D zoom for the MVA measurement was moderate to good by the Bland-Altman plot (ICC = 0.67). The mean MVA measured by 2DE (all 3 methods of direct planimetry, the PTH, and the CE) was significantly larger than that derived by 3DE (both methods of 3DQ and direct planimetry on 3D zoom) (all Ps < 0.05). A moderate agreement between 3DQ and 2D planimetry (ICC = 0.43) was found by the Bland-Altman plot.

CONCLUSIONS

The MVA measurement by direct planimetry on 3D zoom showed a moderate-to-good agreement with 3DQ; it may, thus, be used in clinical practice as a simple method for the measurement of the MVA in patients with MS.

Role of modern 3D echocardiography in valvular heart disease

Three-dimensional (3D) echocardiography has been conceived as one of the most promising methods for the diagnosis of valvular heart disease, and recently has become an integral clinical tool thanks to the development of high quality real-time transesophageal echocardiography (TEE). In particular, for mitral valve diseases, this new approach has proven to be the most unique, powerful, and convincing method for understanding the complicated anatomy of the mitral valve and its dynamism. The method has been useful for surgical management, including robotic mitral valve repair. Moreover, this method has become indispensable for nonsurgical mitral procedures such as edge to edge mitral repair and transcatheter closure of paravaluvular leaks. In addition, color Doppler 3D echo has been valuable to identify the location of the regurgitant orifice and the severity of the mitral regurgitation. For aortic and tricuspid valve diseases, this method may not be quite as valuable as for the mitral valve. However, the necessity of 3D echo is recognized for certain situations even for these valves, such as for evaluating the aortic annulus for transcatheter aortic valve implantation. It is now clear that this method, especially with the continued development of real-time 3D TEE technology, will enhance the diagnosis and management of patients with these valvular heart diseases.