MitraClip: How Do We Reconcile the Inconsistent Findings of MITRA-FR and COAPT?

PURPOSE OF REVIEW: Secondary mitral regurgitation (MR) is a common valvular disorder in patients with left ventricular (LV) dysfunction and is associated with worse morbidity and mortality. New data on percutaneous mitral valve (MV) repair suggest that targeting the valve itself may improve outcomes. Our objective is to review two recent trials (MITRA-FR and COAPT) with regard to percutaneous MV repair. We will dive into their methodology and results and propose potential explanations for their divergent outcomes. RECENT FINDINGS: MITRA-FR and COAPT studied the MitraClip plus guideline-directed medical therapy (GDMT) versus GDMT alone in patients with secondary MR. COAPT found an overwhelming benefit in reduction in HF hospitalization and mortality whereas MITRA-FR found no difference between treatment groups. Patient selection, differences in procedural outcomes, and smaller LV dimensions may explain these diametrically opposed results. Secondary MR is a common valvular disorder with complex pathophysiology. There are certain patients who will not benefit from percutaneous MV repair. The results of MITRA-FR and COAPT suggest that percutaneous MV repair may benefit carefully selected individuals with secondary MR on maximum tolerated doses of GDMT.

The role of transcatheter mitral valve leaflet approximation for the treatment of secondary mitral regurgitation: current status and future prospects.

Introduction: Secondary mitral regurgitation (SMR) is one of the most common valvulopathies and is associated with poor prognosis. Over the past years, medical management and mitral valve repair options have rapidly evolved offering new opportunities for a wide range of patients.Areas covered: We provide an up-to-date review of the value of medical and transcatheter mitral valve leaflet approximation for SMR integrating the results of most recent trials and putting their findings into clinical perspective.Expert opinion: Treatment of SMR requires a multidisciplinary approach with a long-term perspective. After optimization of medical treatment, transcatheter mitral valve repair should be considered in patients with persisting symptomatic severe SMR to improve symptoms and prognosis.

Guide to functional mitral regurgitation: a contemporary review.

Functional mitral regurgitation (FMR) occurs in the absence of organic mitral valve (MV) disease and is a result of LV dysfunction due to ischemic vs. non ischemic etiologies. The prevalence of FMR is increasing, as 2.0-2.5 million people in the USA were diagnosed with FMR in 2000-and this number is expected to double to 4 million by 2030. FMR tends to develop in a significant number of patients after myocardial infarction (MI) and many develop heart failure (HF) subsequently with mortality rates ranging from 15-40% at 1 year. Therefore, there has been much interest and effort to develop optimized methods for quantifying and classifying the severity of FMR, as well as developing effective therapeutic interventions to improve outcomes in patients with significant FMR. Echocardiogram is typically the primary diagnostic method of assessment, however, there have been various technological advances including cardiac CT and cardiac MRI that can better guide quantification and management of this disease. Management of this disease is mostly aimed at optimizing left ventricular (LV) remodeling with surgical and transcatheter management gaining more popularity with recent times. The purpose of this paper is to provide a comprehensive review of the current evaluation methods and interventional strategies for FMR.

Contemporary Management of Secondary Mitral Regurgitation.

Secondary mitral regurgitation (SMR) is a common occurrence in patients with heart failure with reduced ejection fraction. Moderate-severe or severe SMR is associated with increased mortality and hospitalisations from heart failure. Medical and cardiac resynchronisation therapies have been the only treatments proven to improve prognosis in this patient population. The Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy (COAPT) and the Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation (MITRA-FR) RCTs evaluated transcatheter mitral valve repair with MitraClip for treatment of SMR in addition to medical therapy and they had divergent results. The COAPT trial demonstrated that a reduction in SMR with MitraClip resulted in reduced mortality and heart failure hospitalisations along with improved symptoms and quality of life in appropriately selected patients. The MITRA-FR trial did not show any benefit from using MitraClip for patients with SMR. This article summarises the differences in these two trials and suggests a contemporary approach to the management of SMR.

Why Did COAPT Win While MITRA-FR Failed? Defining the Appropriate Patient Population for MitraClip.

In 2018, the world of functional mitral regurgitation changed with the presentation of two trials - Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation (MITRA-FR) and Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT). The trials, which seemed to point in two different directions, raised significant questions for the field. This article looks at the differences in effective regurgitant area, guideline-directed medical therapy, patient selection, technical clues and other reasons why the trials had similar aims but very different findings.