Background: Secondary mitral regurgitation (SMR) is a condition affecting the left ventricle (LV) rather than the mitral valve (MV). If the mitral valve (MV) remains structurally unchanged, enlargement of the left ventricle (LV) or impairment of the papillary muscles (PM) can occur. Several mechanical interventions are available to dictate the resolution of MR. However, there is a lack of robust data to compare mitral valve replacement, mitral valve repair (including subvalvular repair), and transcatheter mitral valve procedures (TMVp). This study aims to compare the effectiveness and clinical outcomes of TMVp using the edge-to-edge mitral valve repair (TEER) technique and standard surgical mitral valve procedures (S-SMVp) in patients with SMR. Methods and analysis: Five cardiac surgery centres from four European countries and Japan have collaborated to create a multicentre observational registry (TEERMISO). The registry will enrol consecutive patients who underwent mechanical intervention for SMR between January 2007 and December 2023. The investigators assessed the difference between replacement and repair for both the standard surgical approach and the transcatheter procedure. The main clinical outcome will be the degree of LV remodelling as assessed by the Left Ventricular End-Diastolic Volume Index at 10 years. The study will measure several secondary endpoints, including all-cause mortality as the primary endpoint, followed by functional status, hospitalisation, neurocognition, physiological measures (echocardiographic assessment), adverse events and reoperation.

The authors have declared no competing interest.

https://register.clinicaltrials.gov/prs/beta/records

This study did not receive any funding

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All data produced in the present study are available upon reasonable request to the authors

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