The potential of mitral valve quantification in cardiovascular surgery

Objective: To identify specifics of mitral valve anatomy in patients with mitral insufficiency of various origin using the Mitral Valve Quantification (MVQ) technique for an optimal choice of mitral valve repair strategy. Materials and methods: The study included 30 patients (17 male and 13 female) with organic or functional mitral regurgitation of various grades (mean age, 48 ± 5 years). The patients were categorized into three groups depending on the etiology of mitral insufficiency. The first group included 15 patients with degenerative mitral valve regurgitation, the second one included 9 patients with ischemic mitral regurgitation, and the third one was a control group with 6 patients with minimal mitral regurgitation and no structural heart abnormalities. A geometrical model of the mitral valve was developed by the MVQ technique with a Philips iE33 ultrasound machine. In all patients, we assessed the geometrical parameters of the mitral annulus, the type of leaflet defects and chordal apparatus of the mitral valve, leaflet coaptation length, and the angle between the aortic and mitral valves. Results: The following patterns were found at comparison of the geometrical parameters of the fibrous mitral annulus. Compared to other groups, the patients with ischemic mitral regurgitation had higher antero-posterior diameter and commissural diameters (48.7 and 45.7 mm, respectively; р < 0.05). They also had higher values of the tenting height and tenting volume, i.e., the mitral coaptation depth (11.9 ± 2.1 mm and 5.9 ± 2.8 mL, respectively; p < 0.05). The prevalence of mitral valve prolapse was higher in the patients with degenerative mitral regurgitation (prolapse height, 6.4 ± 0.9 mm, prolapse volume, 1.3 ± 0.1 mL; р < 0.001). The leaflet coaptation length tended to be higher in the patients with organic lesions of the mitral valve (30 ± 7.5 mm), while the shortest coaptation length was typical for the control group (23 ± 1.6 mm): however, the difference was not statistically significant. The results of the mitral valve chordae tendinea measurements demonstrated that the anterolateral chord was the longest one (31.2 mm versus 21.3 mm of the postero-medial chord) in the group with degenerative mitral valve abnormalities; whereas in those with the ischemic mitral insufficiency and in the control group both chords had similar length. Conclusion: The MVQ allows for diagnosis of the mitral valve abnormalities and makes it possible to perform quantitative and qualitative assessment of the mitral valve geometry in patients with the valve abnormalities of various origins, which may significantly contribute to the choice of mitral valve repair strategy.