Changes in left ventricular function after mitral valve repair for severe organic mitral regurgitation

Abstract

BACKGROUND: Limited data are available on the changes in left ventricular (LV) contractile function at long-term follow-up after mitral valve repair (MVr). Moreover, assessment of LV systolic function in patients undergoing MVr is troublesome with current methods, given that mitral regurgitation is characterized by increased preload and decreased afterload, potentially masking LV dysfunction. The aim of this study was to assess the value of LV global strain (longitudinal and circumferential) measured by speckle tracking analysis for detecting changes in contractile function after MVr. METHODS: A total of 122 patients with organic mitral regurgitation who underwent successful MVr at an early stage (LV ejection fraction>60%, LV end-systolic diameter<40 mm) were included. Echocardiography was performed at baseline and at short-term ( approximately 7 days) and long-term (1 to 3 years) follow-up after MVr. RESULTS: At baseline, LV ejection fraction and LV global strain were higher in patients than in 40 normal control individuals. By contrast, LV forward stroke volume was higher in control individuals than in patients. At short-term follow-up, a significant decrease in LV ejection fraction and LV global strain was noted as a consequence of changes in loading conditions. At long-term follow-up, LV ejection fraction and LV global strain improved significantly. Correction of LV strain for LV size showed a subtle impairment of myocardial contractility at baseline, which significantly improved over time after MVr, together with the improvement in LV forward stroke volume. CONCLUSIONS: Mitral valve repair for organic mitral regurgitation results in a significant increase in LV myocardial contractility as measured by LV global strain corrected by LV size. © 2012 The Society of Thoracic Surgeons.