Predicting outcomes after percutaneous mitral balloon valvotomy: the impact of left ventricular strain imaging

AIMS: This study aimed (1) to evaluate the impact of preprocedural two-dimensional speckle-tracking echocardiography (2D-STE) on long-term outcome after successful percutaneous mitral balloon valvotomy (PMBV) in patients with mitral stenosis (MS) and (2) to determine whether 2D-STE detects underlying diastolic dysfunction as defined by invasive haemodynamic study. METHODS AND RESULTS: Sixty-four consecutive MS patients with preserved left ventricular ejection fraction (LVEF ≥50%) and who underwent successfully PMBV were studied. Successful immediate result was defined as post-procedural mitral valve area ≥1.5 cm2 and ≤2/4 mitral regurgitation by catheterization. During a follow-up of 4.2 ± 3.0 years, there were 7 deaths (11%) and 21 late mitral valve reintervention (33%). Univariate predictors of death were global longitudinal strain (GLS), age, LVEF, and pre- and post-procedural pulmonary artery pressures. In the multivariate Cox model, GLS was the strongest predictor of death [hazard ratio (HR) (95% CI), 1.45 (1.07-2.04); P= 0.01]. For the composite endpoint, GLS and post-procedural left atrial pressure (LAP) were univariate predictors of death or reintervention. At multivariable analysis, GLS and post-procedural LAP remained in the final model with strong trend towards significance [GLS HR (95% CI), 1.17 (0.99-1.37); P= 0.056]. There was no correlation between diastolic dysfunction identified at catheterization and standard echocardiographic and 2D-STE indexes, even after adjustments for age, left ventricular mass, effective arterial elastance (afterload), and end-diastolic volume indexes (preload). CONCLUSION: GLS is a powerful predictor of long-term outcome after successful PMBV and provides incremental prognostic value over traditional parameters. Echocardiographic diagnosis of concomitant diastolic dysfunction in MS patients remains elusive.