Characteristics and results of edge-to-edge transcatheter repair of the mitral valve depending on the mechanism causing mitral regurgitation

Transcatheter edge-to-edge repair (TEER) has been increasingly used for selected patients with mitral regurgitation (MR), but limited data are available regarding clinical outcomes in patients with varied mechanisms of MR. Studies usually identify two types of MR: degenerative mitral regurgitation (DMR) and functional mitral regurgitation (FMR). However, patients with mixed MR etiology (MMR) are usually excluded from studies.

We investigated baseline echocardiographic data and clinical characteristics of three groups. Additionally, we analized the long-term prognostic impact of TEER in patients with clinically significant MR depending on the mechanism causing MR.

Patients (n=191) who had severe MR and underwent TEER between November 2011 and Janury 2024 were included in the study. 116 patients with structurally normal mitral leaflets were classified as FMR, while 42 patients with valvular abnormalities were classified as having DMR. 33 patients with both structural and functional deformation were classified as having MMR.

Baseline echocardiographic and clinical characteristics are summarized in Table 1. Patients with FMR were younger, had fewer comorbidities and had a larger left ventricular size than patients with DMR. Patients with MMR presented intermediate characteristics between patients with FMR and DMR. The median (p25-75) follow-up of patients was 24 (9-50) months. Time-to-event curves of survival in patients with FMR, DMR, MMR was 75% vs. 80% vs. 82%, respectively, and time event-free survival for heart failure hospitalization and all-cause mortality according to severe MR for patients with FMR, DMR, and MMR were 60% vs. 74% vs. 71% (Figure 1). In the follow up, no differences were found in terms of survival and survival free of heart failure admission or all-cause death.

The baseline characteristics of patients with FMR, DMR and MMR treated with TEER are different. Despite this, the prognosis after treatment is similar in the three groups of patients.

Baseline characteristics of patients