Predictors of long-term event-free survival after percutaneous balloon mitral valvuloplasty

Abstract

Previous studies have shown that long-term event-free survival after percutaneous balloon mitral valvuloplasty (PBMV) could be predicted by several baseline characteristics. However, the extent of the predictive variables has not been defined accurately yet. In this study, 40 baseline demographic, clinical, echocardiographic, and hemodynamic variables of 128 consecutive patients with mitral stenosis who underwent PBMV in a single institution, were analyzed in order to predict long-term event-free survival, defined as absence of death, mitral valve replacement, or repeat PBMV. Univariate survival analysis showed that age (p = 0.03), history of commissurotomy or mitral valvuloplasty (p = 0.05), calicum grade (p = 0.008),echo score (p = 0.0001),preprocedure cardiac output (p = 0.03), preprocedure valve area (p = 0.0007), postprocedure mean left atrial pressure (p = 0.0001), postprocedure valve area (p = 0.0001), postprocedure valve gradient (p = 0.013), and postprocedural mitral regurgitation (p = 0.01) were statistically significant predictors of event-free survival. Additionally, the absolute and/or relative procedural change of the following variables were found to be statistically significant predictors of event-free survival: left atrial pressure (p = 0.01), valve area (p = 0.0001), and valve gradient (p = 0.02). Multivariate Cox proportional hazard analysis indicated that when only variables available before the procedure were considered, echo score (p = 0.002) and preprocedure valve area (p = 0.0002) were found to be independent predictors of event-free survival. When both pre- and postprocedure variables were considered, echo score (p = 0.002) and postprocedure valve area (p = 0.0001) were found to be independent predictors of event-free survival. In conclusion, mitral valve morphology reflected by echo score, and baseline and postprocedure mitral valve area were found to be the strongest independent predictors of event-free survival after PBMV.