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

ABSTRACT

BACKGROUND Mitral valve stenosis is one of the most common structural heart diseases in developing countries and is primarily due to rheumatic disease. Percutaneous mitral balloon valvuloplasty (PMBV) has been, since its introduction in 1984, the preferred treat ment. However, restenosis presents 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 pro cedure. The objective of this study was to examine risk mitral valvular restenosis in a significant number of patients submit ted to percutaneous mitral balloon commissurotomy (PMBC) for the treatment of mitral valve stenosis, particularly when secondary to rheumatic heart disease. METHODS This study reports the vast experience of a single high volume tertiary institution where 1,794 consecutive patients were treated with PMBC from 1987 to 2011. The primary end point was to determine the independent predictors of this untoward event, defined as loss of more than 50% of the original increase in maximum valve area (MVA) or MVA < 0.01), preprocedure maximum gradient (HR 1.01; 95% CI 1.00-1.03; P » 0.02), and higher Wilkins score (HR 1.37; 95% CI 1.13-1.66; P < 0.01). RESULTS Mitral valve restenosis was observed in 26% of the cases (n » 483). Mean population age was 36 years, with most patients being female (87%). Mean follow-up duration was 4.8 years. At multivariate analysis, independent preprocedural predictors of restenosis were left atrial diameter (HR 1.03; 95% CI 1.01-1.04; P < 0.01), preprocedure maximum gradient (HR 1.01; 95% CI 1.00-1.03; P » 0.02), and higher Wilkins score (HR 1.37; 95% CI 1.13-1.66; P < 0.01). CONCLUSION In the very-long-term follow-up, mitral valve reste nosis was observed in one-fourth of the population undergoing PMBC. Preprocedure echocardiographic findings for left atrial diameter, maximum valve gradient, and high Wilkins score were found to be the only independent predictors of this deleterious event.