Background: Mitral annulus assessment is of great importance for the diagnosis and treatment of mitral valve disease. The present study sought to assess the value of real-time three-dimensional echocardiography for the assessment of true mitral annulus diameter (MAD).
Methods: One hundred and fifty patients (mean age 38 +/- 18 years) with adequate two-dimensional (2D) echocardiographic image quality underwent assessment of MAD(2D) and MAD(3D) (with real-time three-dimensional echocardiography). In a subgroup of 30 patients true MAD was validated with magnetic resonance imaging (MRI).
Results: There was a good interobserver agreement for MAD(2D) (mean difference = -0.25 +/- 2.90 mm, agreement: -3.16, 2.66) and MAD(3D) (mean difference = 0.29 +/- 2.03, agreement = -1.74, 2.32). Measurements of MAD(2D) and MAD(3D) were well correlated (R = 0.81, P < 0.0001). However, MAD(3D) was significantly larger than MAD(2D) (3.7 +/- 0.9 vs. 3.3 +/- 0.8 cm, P < 0.0001). In the subgroup of 30 patients with MRI validation, MAD(3D) and MAD(MRI) were significantly larger than MAD(2D) (3.3 +/- 0.5 and 3.4 +/- 0.5 cm vs. 2.9 +/- 0.4 cm, both P < 0.001). There was no significant difference between MAD(MRI) and MAD(3D).
Conclusion: MAD(3D) can be reliably measured and is superior to MAD(2D) in the assessment of true mitral annular size.