RT Book, Section A1 Bax, Jeroen J. A1 Marsan, Nina Ajmone A1 Bijl, Pieter van der A1 Treede, Hendrik A1 DeBonis, Michele A1 Prendergast, Bernard A1 Iung, Bernard A1 Delgado, Victoria A2 Fuster, Valentin A2 Narula, Jagat A2 Vaishnava, Prashant A2 Leon, Martin B. A2 Callans, David J. A2 Rumsfeld, John A2 Poppas, Athena SR Print(0) ID 1191373652 T1 Mitral Regurgitation T2 Fuster and Hurst's The Heart, 15e YR 2022 FD 2022 PB McGraw-Hill Education PP New York, NY SN 9781264257560 LK accesscardiology.mhmedical.com/content.aspx?aid=1191373652 RD 2023/02/07 AB Chapter SummaryThis chapter provides a comprehensive overview of the epidemiology, pathophysiology, diagnosis, and treatment of primary and secondary mitral regurgitation (MR). MR is the most frequent valve disease in the population (estimated prevalence 20%) and, as a disease of the elderly, prevalence will increase steeply over the next few decades. Primary MR results from valvular abnormalities whereas secondary MR is a consequence of left ventricular dysfunction/dilatation or left atrial enlargement/dysfunction (see Fuster and Hurst's Central Illustration). Significant MR is associated with high morbidity/mortality when left untreated, with 5-year survival of 46 ± 3% in secondary MR and 66 ± 3% in primary MR. Still, most MR patients are treated conservatively. MR diagnosis/quantification is performed with two- and three-dimensional transthoracic echocardiography, which provides anatomical and functional information to understand the MR pathophysiology. Cardiac magnetic resonance is ideal for MR quantification. When transcatheter mitral valve repair/replacement is being considered, detailed anatomical imaging of the mitral valve (including annular calcification) can be provided by cardiac computed tomography. Surgical therapies and transcatheter mitral valve repair/replacement are discussed, and a summary of the recommendations from the latest ESC/EACTS and ACC/AHA guidelines for treatment of primary and secondary MR is provided.