Novel prognostic score for immediate and late success after percutaneous mitral balloon commissurotomy in patients with mitral stenosis

ABSTRACT

INTRODUCTION: Percutaneous mitral balloon commissurotomy (PMBC) remains the preferred treatment for patients with severe symptomatic rheumatic mitral stenosis (MS) and suitable anatomy. OBJECTIVE: The objective of this study was to propose a new score for the prediction of immediate and late success. METHODS: This is a retrospective, single-center, single-arm registry encompassing all 1915 consecutive patients with rheumatic mitral stenosis recruited and referred to PMBC between August 3rd 1987 and July 19th 2010. All data were previously collected and recorded in a dataset. Clinical status was determined according to the New York Heart Association (NYHA) classification. Long-term outcome was a composite of incidence of major adverse cardiac events (cardiovascular death, new PMBC or mitral valve repair surgery) up to 24 years of clinical follow-up (from 1988 until December 3rd, 2011), including cardiovascular death, need for new PMBC, or mitral valve replacement surgery. RESULTS: Mean patient age was 36.8 ± 12.9 years, most (86.4%) were female, and Wilkins score was between 9-11 in 49.1% of patients. In the multivariate analysis, the predictors of immediate success were age (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.96-0.99; p = 0.01), left atrium size (OR, 0.96; 95% CI, 0.93-0.99; p = 0.01), mean pre-procedure mitral gradient (OR, 0.93; 95% CI, 0.89-0.96; p < 0.001), intermediate Wilkins score 9-11 (OR, 0.62; 95% CI, 0.40-0.94; p = 0.02), and high Wilkins score ≥12 (OR, 0.35; 95% CI, 0.16-0.76; p < 0.01). For prediction of late events, age (hazard ratio [HR], 0.98; 95% CI, 0.97-0.98; p < 0.001), New York Heart Association class III-IV (HR, 1.50; 95% CI, 1.18-1.92; p < 0.001), left atrium size (HR, 1.02; 95% CI, 1.02-0.04; p < 0.01), and high Wilkins score ≥12 (HR, 2.02; 95% CI, 1.30-3.15; p < 0.01) were significant. Two nomograms were developed using significant predictors from the model (one for immediate results and another for long-term results). CONCLUSIONS: In this large population, not only the Wilkins score, but also clinical and hemodynamic features, seem to be relevant in predicting immediate and late success for patients with rheumatic MS who underwent PMBC.