Non-invasive assessment of underlying diastolic dysfunction in patients with symptomatic mitral stenosis: the role of strain echocardiography

Abstract

Background: Undetected LV diastolic dysfunction in patients with mitral stenosis (MS) may reduce the benefit of mitral baloon valvotomy. Classical echocardiographic features of diastolic dysfunction are obscured by the effects of MS. We investigated the potential of strain echocardiography to overcome these limitations. Methods: LV strain was measured by 2D speckle tracking in MS patients undergoing percutaneous mitral balloon valvotomy. LV end-diastolic pressure (LVEDP) >15 mmHg at catheterization was considered a marker of diastolic dysfunction. The effects of demographics, MS severity, comorbidities, hemodynamic and LV strain indexes on LVEDP were analyzed. Results: Of 20 patients (65±12 years, 95% female), 11 had diastolic dysfunction. Univariate predictors of high LVEDP were longitudinal strain indexes (global peak longitudinal systolic strain, GPLSS; peak systolic and early diastolic strain rate), BMI, mitral gradient, and pulmonary artery pressure. At multivariate analysis, GPLSS and mean gradient were excellent in predicting LVEDP (model r2=0.80, p<0.01); this was mainly due to a good correlation between GPLSS and LVEDP (r2=0.60; Figure, left). For similar mitral valve area (Figure, middle), patients with high LVEDP had lower MG (Figure, right). This demonstrates valvular disease severity and LV diastolic dysfunction both impede left ventricular filling in patients with MS and diastolic dysfunction. Conclusions: Abnormal GPLSS is a strong predictor of diastolic dysfunction in patients with symptomatic MS. Strain echocardiography should be considered for evaluation of unsuspected diastolic dysfunction in MS patients. Mitral valve gradient is influenced by both MS severity and LV diastolic dysfunction.