Independent clinical and echocardiographic predictors of restenosis after percutaneous mitral balloon commissurotomy followed for 24 years

RESUMO

INTRODUCTION: Mitral valve stenosis (MVS) is one of the most common structural heart diseases in developing countries, primarily due to rheumatic disease. Percutaneous mitral balloon valvuloplasty (PMBV) has been, since its introduction in 1984, the preferred option of treatment for such disease. However, restenosis is presented with an approximate incidence of 20%. Echocardiographic scoring of the mitral apparatus has been the main tool used to indicate and foresee the possible result of the procedure. OBJECTIVE: The objective of this study was to enlight risk factors of mitral valvular restenosis in a significant number of patients submitted to percutaneous mitral balloon commissurotomy for the treatment of mitral stenosis (MS), particularly when secondary to rheumatic heart disease. METHODS: This study reports the vast experience of a single center high volume tertiary institution where 1.794 consecutive patients were treated with PMBC between 1987 and 2011. The primary endpoint was to determine the independent predictors of this untoward event, defined as loss of over 50% of the original increase in maximum valve area (MVA) or MVA < 1.5 cm2. RESULTS: Mitral valve restenosis was observed in 26% of the cases (n = 483). Mean population age was 36 years old, with most patients being female (87%). Mean follow up duration was 4.8 years. At multivariate analysis independent pre-procedural predictors of restenosis were left atrial diameter (HR 1.03, 95% ci 1.01-1.04, p < 0.01), pre procedure maximum gradient (HR 1.01, 95% ci 1.00-1.03, p = 0.02) and higher wilkins scores (HR 1.37, 95% ci 1.13-1.66, p < 0.01). CONCLUSION: In the very long term follow-up, mitral valve restenosis was observed in a quarter of the population undergoing PMBC. Preprocedure echocardiographic findings, including left atrial diameter, maximum valve gradient and high Wilkins scores were found to be the only independent predictors of this deleterious event.