LAUSR

Mitral regurgitation (MR) is the most frequent heart valve disease in the community and the second most frequent cause of hospital referral.1–3 The distinction between primary and secondary MR is of utmost importance since they differ not only in the mechanism causing valve failure but also in their prevalence, prognosis and treatment. Primary MR is caused by leaflet and/or chordae anomalies, and surgery improves the prognosis of symptomatic patients or those with haemodynamic consequences. Secondary MR is caused by a disease of the left ventricle or the left atrium (or both), is frequent in the community4 and is associated with lower event-free survival than primary MR of similar magnitude.5 While medical treatment and resynchronization improve prognosis, uncertainty remains regarding the benefit of surgery in these patients.6 Edge-to-edge transcatheter mitral valve repair (TMVr) has been largely adopted in clinical practice. Likewise surgery, there is uniform agreement that TMVr is indicated in patients with primary MR at high risk for surgery as stated in current guidelines.6,7 More questionable is the benefit of TMVr in patients with secondary MR, with major discordances between the two randomized trials MITRA-FR and COAPT.8,9 Nonetheless, there is no doubt that TMVr has strengthened interest in secondary MR since the possibility of less invasive intervention appears particularly attractive for this disease subject to concerns on the risk–benefit ratio of interventions on the mitral valve. Indeed, previous European registries have shown a predominance of secondary MR in patients treated with TMVr.