Transcatheter Mitral Valve Replacement for Patients With Symptomatic Mitral Regurgitation: A Global Feasibility Trial

Abstract

Background: Symptomatic mitral regurgitation (MR) is associated with high morbidity and mortality that can be ameliorated by surgical valve repair or replacement. Despite this, many patients with MR do not undergo surgery. Transcatheter mitral valve replacement (TMVR) may be an option for selected patients with severe MR.

Objectives: This study aimed to examine the effectiveness and safety of TMVR in a cohort of patients with native valve MR who were at high risk for cardiac surgery.

Methods: Patients underwent transcatheter, transapical delivery of a self-expanding mitral valve prosthesis and were examined in a prospective registry for short-term and 30-day outcomes.

Results: Thirty patients (age 75.6 ± 9.2 years; 25 men) with grade 3 or 4 MR underwent TMVR. The MR etiology was secondary (n = 23), primary (n = 3), or mixed pathology (n = 4). The Society of Thoracic Surgeons Predicted Risk of Mortality was 7.3 ± 5.7%. Successful device implantation was achieved in 28 patients (93.3%). There were no acute deaths, strokes, or myocardial infarctions. One patient died 13 days after TMVR from hospital-acquired pneumonia. Prosthetic leaflet thrombosis was detected in 1 patient at follow-up and resolved after increased oral anticoagulation with warfarin. At 30 days, transthoracic echocardiography showed mild (1+) central MR in 1 patient, and no residual MR in the remaining 26 patients with valves in situ. The left ventricular end-diastolic volume index decreased (90.1 ± 28.2 ml/m² at baseline vs. 72.1 ± 19.3 ml/m² at follow-up; p = 0.0012), as did the left ventricular end-systolic volume index (48.4 ± 19.7 ml/m² vs. 43.1 ± 16.2 ml/m²; p = 0.18). Seventy-five percent of the patients reported mild or no symptoms at follow-up (New York Heart Association functional class I or II). Successful device implantation free of cardiovascular mortality, stroke, and device malfunction at 30 days was 86.6%.

Conclusions: TMVR is an effective and safe therapy for selected patients with symptomatic native MR. Further evaluation of TMVR using prostheses specifically designed for the mitral valve is warranted. This intervention may help address an unmet need in patients at high risk for surgery. (Early Feasibility Study of the Tendyne Mitral Valve System [Global Feasibility Study]; NCT02321514).

Keywords: heart failure; mitral prosthesis; mitral regurgitation; mitral valve implantation; transcatheter.