LAUSR

© Author(s) (or their employer(s)) 2023. No commercial reuse. See rights and permissions. Published by BMJ. INTRODUCTION Mitral annular calcification (MAC) is a degenerative process of the fibrous base of the mitral valve. Most patients with MAC present with mild or moderate severity of the calcification pattern, whereas severe MAC is rather rare. It increases the risk for mitral valve dysfunction (regurgitation and/or stenosis). Predisposing factors for MAC include advanced age, female gender or chronic kidney disease (especially if dialysis dependent), and it is frequently associated with atrial fibrillation, stroke, infective endocarditis or coronary artery disease. Furthermore, MAC has been shown to be independently associated with the severity of arteriosclerotic comorbidities (ie, carotid artery plaques). Due to their comorbidities and anatomical characteristics, patients with MAC typically present with high surgical risk. Furthermore, surgical treatment is technically demanding and accompanied by a high risk of paravalvular leakage (PVL), circumflex artery injury or atrioventricular groove disruption. Therefore, to minimise procedural risk, several transcatheterbased techniques have been proposed as alternative treatment options in patients with MAC. This article reviews both surgical and transcatheterbased treatment strategies and proposes a riskbased and anatomybased therapy allocation algorithm.