Pathomorphological characteristics of resected mitral valves after unsuccessful valvuloplasty

Percutaneous mitral valvuloplasty has been shown to be an acceptable alternative to surgery as treatment for selected patients with severe mitral stenosis. We examined hemodynamic, echocardiographic, and pathomorphologic findings in a series of 308 patients undergoing balloon valvuloplasty, 41 of whom underwent subsequent surgery, in search of possible predictors of an unsuccessful outcome.

Patients with severe mitral stenosis underwent Inoue single ballon valvuloplasty over a 48-month period and had follow-up for a mean of 14.5+/-16.8 months (range 1 to 64 months). Of the 308 patients, 267 (Group I) were clinically improved and stable throughout follow-up, while subsequent surgery was required in 41 (Group II) after 38.2+/-143.5 days (range 1 to 1212). Significant differences between the groups were observed for NYHA class (2.7+/-0.6 vs 2.9+/-0.6, p<0.05), mitral valve area (1.0+/-0.3 vs 0.9+/-0.2 cm2, p<0.01) and left atrial endsystolic dimension by echo (51.3+/-8.0 vs 55.4+/-10.2 mm, p<0.01). Two of the 41 Group II patients underwent surgery for left to right shunting, 1 for tamponade and 2 were lost to follow-up. The excised mitral valves of the remaining 36 patients all showed calcification and/or fibrosis: 9 homogenous, 5 non-homogenous; 19 were classified as having a funnel-shaped deformity, and 3 did not fit into a discrete category. Among the funnel-shaped valves, 13 had a tear versus 6 where dilation was primarily accomplished by stretching. Only one of 9 valves with homogenous calcification was torn, whereas a tear was noted in 3 of the 5 with non-homogenous calcification.

Funnel-shaped valves and those with non-homogenous distribution of calcification and/or fibrosis appear to be least suitable for balloon valvuloplasty.