MITRA-EF: A Multi-Center Registry Evaluating Left Ventricular Function in Patients Undergoing Transcatheter Mitral Edge-To-Edge Repair

Following surgical mitral valve repair for primary mitral regurgitation (MR), improved left ventricular (LV) and left atrial remodeling was demonstrated. However, little is known regarding the impact of percutaneous mitral edge-to-edge repair in patients with secondary MR or those with primary MR who are not candidates for surgery. Studies in these populations are limited, vary in the inclusion criteria and the etiology of mitral regurgitation. Some show no improvement in LV ejection function (LVEF) following percutaneous repair despite reduced LV end-diastolic diameter (LVEDD) and LV end-systolic diameter (LVESD), whereas in others an improvement in LVEF was shown. One study suggests reverse remodeling only in patients with lower values of logistic EuroSCORE and STS scores, LV end-diastolic volume index (LVEDVi), right ventricular end systolic area, and pulmonary artery systolic pressure (PAPs) at baseline evaluation and in multivariate analysis, only PAPs remained an independent predictor of improvement. Another study utilizing cardiovascular magnetic resonance to assess extent and predictors of reverse remodeling (defined by reduction of LVEDVi>15% compared to baseline) demonstrated improvement in only 34% of the patients, predicted by improvement in MR volume and MR fraction. In the landmark Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (The COAPT Trial), LVEF had deteriorated following both repair and the control arm of medical therapy alone, albeit at a lower rate in patients treated with the MitraClip device (reduction of 5.6±1.2% versus 8.8±1.1%, p=0.048).

It was shown, in a few preliminary trials, that a significant number of patients undergoing transcatheter mitral edge-to-edge repair suffer from an acute reduction in left ventricular function. This so called "afterload mismatch" resulted in worsened prognosis in this patient population, as compared with controls.

Nevertheless, the information available in the current literature is limited and based on relatively smaller studies. We therefore wish to learn more about patients undergoing transcatheter mitral edge-to-edge repair, encompassing both primary and secondary mitral regurgitation, assess dynamics in left ventricular function during and after the admission, identify predictors of an acute reduction in left ventricular function and understand its impact on prognosis.

In this international, multicenter registry, consecutive patients undergoing TEER are included. We aim to assess changes in LVEF and LV end-diastolic volume (LVEDV) immediately after the procedure. We will then assess rates of AM, defined as a reduction of >15% in LVEF or an increase of >15% in LVEDV, its impact on all-cause mortality, MACE (composite end point of all-cause death, surgery and grade 3+ or 4+ mitral regurgitation) and LVEF at 12 months, as well as predictors for AM.