INOUE BALLOON MITRAL VALVOTOMY IN PATIENTS WITH SEVERE VALVULAR AND SUBVALVULAR DEFORMITY

Objectives. This study evaluated the immediate and long-term results o f percutaneous Inoue balloon mitral valvotomy in patients with severe valvular and subvalvular deformity. Methods. We reviewed the prevalvot omy transthoracic echocardiagrams of patients from the North American multicenter Inoue registry with total Massachusetts General Hospital ( MGH) echocardiographic scores greater than or equal to 10. The echocar diograms were rescored by two investigators to assess valvular and sub valvular morphology to eliminate interinstitutional variability. Ninet y patients were originally assigned scores greater than or equal to 10 . After rescoring, 18 patients (20%) were eliminated, leaving 72 study patients. Results. Balloon mitral valvotomy was technically successfu l in 69 (96%) of the 72 patients. Mean (+/-SD) mitral valve area incre ased from 0.9 +/- 0.3 to 1.5 +/- 0.5 cm(2). An immediate optimal resul t, defined as greater than or equal to 50% increase in mitral valve ar ea or a final area greater than or equal to 1.5 cm(2) with no major co mplications, was achieved in 46 patients (64%). End paints for clinica l follow-up (events) included mitral valve replacement, repeat valvoto my 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 patie nts (13%) died, and 32 patients (45%) were in New York Heart Associati on functional class I or II. Univariate predictors of an immediate opt imal result included sinus rhythm, male gender and a lower University of Southern California commissural calcium score. Only sinus rhythm pr edicted an optimal result by multivariate analysis. Actuarial 3-year e vent-free survival was 42%. Univariate predictors of event-free surviv al were a lower grade of mitral regurgitation, lower MGH total echocar diographic score, lower MGH leaflet thickness subscore and lower preva lvotomy left ventricular systolic pressure. Only grade of mitral regur gitation 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 cardio vascular event rate in follow-up. Mitral valve replacement should be considered in s urgical candidates with an MGH total echocardiographic score greater t han or equal to 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 a nd high surgical risk.