Percutaneous Transcatheter Mitral Valve Replacement

Mitral regurgitation (MR) is one of the most prevalent valvular heart diseases in Western countries. The current estimated prevalence of moderate and severe MR in the United States is 2 to 2.5 million, and it is expected that this number will rise to 5 million by 2030.1 Surgical intervention is recommended for symptomatic severe MR or asymptomatic severe MR with left ventricular (LV) dysfunction.2 Treatment of degenerative MR has evolved from mitral valve (MV) replacement to MV repair because of superior long-term outcomes after repair.2–4 For functional MR, however, the benefit over MV replacement is less certain.5 In addition, minimally invasive MV surgery has become a well-established and increasingly used option for managing patients with MV pathology.6Although surgery remains the gold standard treatment for significant MR, MV surgery is deferred in a large number of patients because of high surgical risk.7 The decrease in the prevalence of rheumatic valve disease, in combination with an increased life expectancy, has led to a high prevalence of degenerative MR. As a consequence, patients are older and present with comorbidities that increase operative mortality and morbidity risks.8 In octogenarians, there has been reported a mortality and morbidity rate of 17.0% and 35.5%, respectively, following MV surgery.9 This results in denial or nonreferral for surgery in a large group of patients with significant MR—the Euro Heart Survey revealed that up to 50% of patients hospitalized with symptomatic severe MR are not referred for MV surgery, mainly because of advanced age, comorbidities, and LV dysfunction. In patients aged ≥80 years, surgical treatment was performed in only 15% compared to 60% in patients aged ≤70 years.8,10The observation that a significant number of patients are not referred for MV surgery and the desire …