Renal Outcomes Following Transcatheter Mitral Valve Repair - Analysis of COAPT Trial Data

The prevalence of valvular heart disease in the United States has been estimated at 4.2-to-5.6 million, with mitral regurgitation (MR) being the most common lesion. Significant MR is associated with heart failure (HF) and death if left untreated. When HF is present, renal dysfunction (RD) is common and is associated with worse outcomes (ie, it is a marker of HF disease progression). Additionally, a complex interplay exists in patients with HF who also have MR, as this combination further impairs renal function, and the presence of RD further worsens prognosis and often limits guideline-directed management and therapy (GDMT). This has important implications in secondary MR because GDMT is the standard of care. However, with the development of minimally invasive transcatheter mitral valve repair, mitral transcatheter edge-to-edge repair (TEER) has become a new treatment option for secondary MR that is now incorporated into current guidelines published in 2020 that listed mitral TEER as a class 2a recommendation (moderate recommendation with benefit >> risk) as an addition to GDMT in a subset of patients with left ventricular ejection fraction <50%. The Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial, which demonstrated favorable outcomes in secondary MR by adding mitral TEER to GDMT versus GDMT alone, was the evidence base for these guidelines. Considering these guidelines and the understanding that concomitant RD often limits GDMT in secondary MR, there is emerging research studying the renal outcomes from the COAPT trial. This review analyzes this evidence, which could further influence current decision-making and future guidelines.