Objectives: This study evaluated the immediate and long-term results of percutaneous Inoue balloon mitral valvotomy in patients with severe valvular and subvalvular deformity.
Methods: We reviewed the prevalvotomy transthoracic echocardiograms of patients from the North American multicenter Inoue registry with total Massachusetts General Hospital (MGH) echocardiographic scores > or = 10. The echocardiograms were rescored by two investigators to assess valvular and subvalvular morphology to eliminate interinstitutional variability. Ninety patients were originally assigned scores > or = 10. After rescoring, 18 patients (20%) were eliminated, leaving 72 study patients.
Results: Balloon mitral valvotomy was technically successful in 69 (96%) of the 72 patients. Mean (+/- SD) mitral valve area increased from 0.9 +/- 0.3 to 1.5 +/- 0.5 cm2. An immediate optimal result, defined as > or = 50% increase in mitral valve area or a final area > or = 1.5 cm2 with no major complications, was achieved in 46 patients (64%). End points for clinical follow-up (events) included mitral valve replacement, repeat valvotomy or death. At a mean follow-up of 22.9 +/- 11.0 months, 22 patients (31%) required mitral valve replacement or a second valvotomy, 9 patients (13%) died, and 32 patients (45%) were in New York Heart Association functional class I or II. Univariate predictors of an immediate optimal result included sinus rhythm, male gender and a lower University of Southern California commissural calcium score. Only sinus rhythm predicted an optimal result by multivariate analysis. Actuarial 3-year event-free survival was 42%. Univariate predictors of event-free survival were a lower grade of mitral regurgitation, lower MGH total echocardiographic score, lower MGH leaflet thickness subscore and lower prevalvotomy left ventricular systolic pressure. Only grade of mitral regurgitation after valvotomy predicted event-free survival by multivariate analysis.
Conclusions: Inoue mitral valvotomy in patients with severe valvular and subvalvular deformity has a high technical success rate and good immediate hemodynamic result but a high cardiovascular event rate in follow-up. Mitral valve replacement should be considered in surgical candidates with an MGH total echocardiographic score > or = 10 because it may be able to provide better long-term event-free survival. Balloon valvotomy remains a reasonable palliative therapeutic option for some patients with severe valvular deformity and high surgical risk.