Long-term outcomes of significant mitral regurgitation after percutaneous mitral valvuloplasty

Mild commissural mitral regurgitation (MR) is associated with significantly higher restenosis-free survival after percutaneous mitral valvuloplasty (PMV), which suggests that different mechanisms of significant MR after PMV may have different clinical courses. We therefore analyzed long-term prognostic factors of significant MR after PMV.

Echocardiographic and clinical follow-up data on 380 patients were analyzed (286 women, mean age 44+/-11 years) who underwent PMV with the Inoue balloon technique between 1995 and 2000. Significant MR developed in 47 patients (12.4%). The survival rate at 8 years was 96+/-3% and 98+/-10% in patients with and without significant MR, respectively (P=0.084). The most frequent mechanism was commissural MR, or MR that originated at the site of successful commissurotomy, which occurred in 27 of 47 patients (57%), whereas noncommissural MR occurred in 20 (43%) patients, 12 (26%) with subvalvular damage resulting in chordae rupture and flail motion and 8 (17%) with leaflet laceration. The 8-year event-free survival rate was significantly lower in patients with significant MR than in those without (47+/-8% versus 83+/-3%, P<0.001) and was significantly higher in patients with commissural versus noncommissural MR (63+/-11% versus 29+/-11%, P<0.001). Of the 47 patients with significant MR, who were followed up for 74+/-29 months, 19 patients (40%) underwent mitral valve replacement, and 28 patients (60%) received medical treatment only. Patients with commissural MR had a significantly lower rate of mitral valve replacement than patients with noncommissural MR (15% versus 70%, P<0.001). Multivariate analysis showed that atrial fibrillation (odds ratio, 7.4; 95% CI, 1.1 to 56.4; P=0.038), mean mitral gradient immediately after PMV (odds ratio, 1.5; 95% CI, 1.1 to 2.0; P=0.009), and the mechanism of MR (odds ratio, 16.7; 95% CI, 2.3 to 122.2; P=0.005) were independent factors associated with mitral valve replacement.

Clinical outcome of patients with significant MR after PMV varied according to MR mechanism and the adequacy of hemodynamic improvement, which is easily assessed by echocardiography immediately after PMV.