CHAPTER SUMMARY AND CENTRAL ILLUSTRATION
MitraClip Continues to Outperform Medical Therapy Alone at 5-years, but Event Rates Remain High
The COAPT trial investigators randomized 614 patients with heart failure with left ventricular reduced ejection fraction (20-50%) on maximally tolerated guideline-directed medical therapy and symptomatic moderate-to-severe or severe secondary mitral regurgitation to either transcatheter edge-to-edge repair (TEER) with the MitraClip (Abbott) (n = 302) or medical therapy alone (n = 312). Read More
This 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.
eFig 30-01 Chapter 30: Mitral Regurgitation
Mitral regurgitation (MR) is (together with aortic stenosis) the most frequent heart valve disease in the general population, and particularly is a disease of the elderly. In a nationwide, hospital-based survey in Sweden (including 10,164,211 individuals) performed between 2003 and 2010, the incidence of valvular heart disease was 63.9 per 100,000 person-years, with 24.2% being MR.1 Importantly, the majority (almost 70%) of heart valve diseases was diagnosed in elderly patients (aged ≥65 years).
More recently, the findings in the OxVALVE Population Cohort Study (OxVALVE-PCS, an ongoing prospective cohort study conducted in Oxfordshire, United Kingdom) were reported.2 This study is a cross-sectional analysis of a primary care population (n = 2500 patients, aged ≥65 years); the patients were screened for undiagnosed heart valve disease with the use of transthoracic echocardiography (TTE). In 19.8% of the participants, the presence of mild MR was diagnosed, with 2.3% having moderate-to-severe MR. Based on projection of these observations using population data, it is estimated that the prevalence of clinically significant heart valve disease will double before the year 2050, with a major contribution of MR.