Transcatheter edge-to-edge mitral valve repair (m-TEER) with m-TEER devices has been established as an effective intervention for degenerative and functional mitral regurgitation (MR) in high-risk patients and those contraindicated for heart surgery.1, 2, 3, 4, 5 This treatment improves mitral valve leaflet coaptation and reduces MR; however, it creates multiple orifices with a significantly smaller mitral valve orifice area (MVA), and it may cause iatrogenic mitral stenosis (MS) with an elevated mean transmitral pressure gradient (TMPG).6,7 Pivotal trials of m-TEER excluded patients who had a preprocedural MVA (MVApre) of <4.0 cm2 to avoid this complication.1, 2, 3 However, patients with a relatively small MVApre typically undergo this procedure in clinical practice. Therefore, clarifying the clinical impact of iatrogenic MS is of paramount importance.

The Mitral Valve Academic Research Consortium defined the development of new MS due to device as a small postprocedural MVA (MVApost) or high TMPG.8 The relationship between TMPG and long-term clinical outcomes has been discussed substantially but remains controversial.9, 10, 11, 12, 13 However, only a few reports have examined the impact of small MVApost after m-TEER on clinical events.7 We hypothesized that iatrogenic MS defined by a small MVApost may influence long-term prognosis. Therefore, the purpose of this study was to investigate the long-term clinical impact of MVApost derived from three-dimensional (3D) transesophageal echocardiography (TEE).