Page 51 - Advanced echocardiography in characterization and management of patients with secondary mitral regurgitation
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Introduction
The results of current landmark randomized trials evaluating the prognostic impact of transcatheter mitral valve repair therapy (using the MitraClip device [Abbott Vascular, Menlo Park, California]) in patients with secondary mitral regurgitation (MR) have underscored the relevance of patient selection for this treatment (1,2). MitraClip therapy did not confer a survival benefit compared with optimal medical therapy in the MITRA-FR (Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation) trial (1), whereas in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial, patients randomized to the MitraClip arm had significant reduction in the composite endpoint of heart failure hospitalization and all-cause mortality (2). One of the factors underlying these discrepant results is the difference in left ventricular (LV) volumes between the study populations. Besides differences in grading MR between the 2 trials, patients enrolled in the MITRA-FR trial had larger LV volumes as compared with patients included in the COAPT trial. In contrast, LV ejection fraction (LVEF) was comparable in the 2 study populations. These facts suggest that patients included in the MITRA-FR trial had more advanced LV remodeling status as compared with patients included in the COAPT trial and that LVEF may not be an appropriate parameter to identify the patients who will benefit from mitral valve intervention. However, current guidelines base the recommendation to perform mitral valve surgery in heart failure patients with secondary MR on LVEF (3). In light of the available evidence, the method to assess LV systolic function in severe secondary MR that will identify the patients who will improve their prognosis with mitral valve intervention remains an unmet clinical need (4). Two-dimensional (2D) LV global longitudinal strain (GLS) measured with speckle tracking echocardiography has demonstrated more advanced LV damage (myocardial fibrosis) than LVEF in patients with nonischemic cardiomyopathy and severe secondary MR (5). However, the prognostic implications of LV GLS in patients with secondary MR have not been investigated. Accordingly, the aim of the present study was to evaluate the prognostic value of LV GLS over LVEF in a large cohort of patients with significant secondary MR.
Methods
Patient population
Patients with moderate and severe secondary MR, of both ischemic and nonischemic etiology, were identified retrospectively from the departmental clinical database (EPD-Vision 11.8.4.0, Leiden University Medical Center, Leiden, the Netherlands) and
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