Transcatheter edge-to-edge repair for primary mitral regurgitation: what lies ahead?

Primary mitral regurgitation (PMR) results from intrinsic alterations of the mitral valve apparatus, most commonly related to fibroelastic deficiency or myxomatous degeneration in high-income countries. If left untreated, it leads to progressive left ventricular remodelling, heart failure, and increased mortality. Surgical mitral valve repair remains the gold-standard treatment, offering excellent long-term outcomes and durable correction of regurgitation.12 Over the past decade, mitral transcatheter edge-to-edge repair (M-TEER) has emerged as an important therapeutic alternative for patients with PMR who are at high or prohibitive surgical risk.13 By approximating the mitral leaflets, M-TEER enables the effective reduction of mitral regurgitation (MR) with a favourable safety profile, and has rapidly expanded in clinical practice.3 However, its mechanism – functional leaflet coaptation rather than anatomical correction – raises intrinsic questions regarding its long-term durability in degenerative disease. Indeed, PMR likely represents the most challenging substrate for M-TEER in terms of sustained results. Unlike secondary MR (SMR), where recurrence is mainly driven by progressive remodelling,...