Echocardiographic assessment of mitral valve morphology after Percutaneous Transvenous Mitral Commissurotomy (PTMC)

Abstract

Aims: PTMC produces significant changes in mitral valve morphology as improvement in leaflets mobility. The determinants of such improvement have not been assessed before.

Methods and results: The study included 291 symptomatic patients with mitral stenosis undergoing PTMC. Post-PTMC subvalvular splitting area was a determinant of post-PTMC excursion in both the anterior (B 0.16, 95% CI 0.03 to 0.30, p < 0.05) and the posterior (B 0.12, 95% CI 0.01 to 0.24, p < 0.05) leaflets. Another determinant was the post-PTMC transmitral pressure gradient for anterior (B -0.02, 95% CI -0.04 to -0.005, p < 0.01) and posterior (B -0.01, 95% CI -0.04 to -0.005, p < 0.05) leaflets excursion. The relationship between post-PTMC MVA and leaflet excursion was non-linear "S curve". There was a steep increase of both anterior (p, 0.02) and posterior (p, 0.03) leaflets excursion with increased MVA till the MVA reached a value of about 1.5 cm2; after which both linear and S curves became nearly parallel.

Conclusion: The improvement in leaflets excursion after PTMC is determined by several morphologic and hemodynamic changes produced in the valve. The increase in MVA improves mobility within limit; after which any further increase in MVA is not associated by a significant improvement in mobility in both leaflets.

Figure 1

Anterior and posterior leaflets excursion measured in parasternal long axis view. RV, right ventricle; LV, left ventricle; LA, left atrium; Ao, aorta; ALE, anterior leaflet excursion; PLE, posterior leaflet excursion.

Figure 2

Subvalvular splitting area (white arrow) measured in apical long axis view.

Figure 3

A. Bilateral commissural fusion with commissural score 0 in both commissures, B. Partial splitting of both commissures with score 0.5 in each (total score 1), C. Complete splitting of both commissures with score 1 in each (total score 2), D. Complete splitting of the posterior commissure with score 1 and partial splitting of the anterior commissure with score 0.5 (total score 1.5).

Figure 4

A case of mitral stenosis before and after PTMC in the parasternal long axis view (A, D), short axis view (B, E), and continuous wave Doppler transmitral flow (C, F).

Figure 5

Relationship between post-PTMC mitral valve area and leaflet excursion.

Figure 6

Bland-Altman plots for interobserver variability in anterior leaflet excursion (A), posterior leaflet excursion (B), and subvalvular splitting area (C).