Mitral Regurgitation: Epidemiology and Treatment Options
Mitral regurgitation (MR), the systolic flow reversal from the left ventricle to the left atrium, is one of the most common valvular disorders outside developing countries, where untreated rheumatic valvular heart disease still remains common. The prevalence rate of MR is 1.7% in the general population,1 and increases to more than 10% in individuals aged 75 years and older.2 Without adequate treatment, severe MR leads to left ventricular dysfunction (LVD) and congestive heart failure (HF). An analysis of electronic medical records of 1095 patients with a diagnosis of severe MR and HF determined that the overall 1-year and 5-year mortality rate in patients who did not receive surgery was 20% and 50%, respectively.3
Surgical repair or replacement of the mitral valve are both options for treatment of MR. In recent years, the rate of repair has significantly outstripped that of replacement, due in part to significantly lower operative risks with that modality. However, approximately half of patients with severe MR are denied surgery due to the presence of comorbidities, advanced age or severe LVD. Until the past decade, patients with MR who were who were deemed ineligible for surgical repair or replacement had no options beyond medical therapy.4
MitraClip: An Overview
MitraClip (Abbott Vascular, Menlo Park, CA) is a transcatheter mitral valve repair system based on an artificial double-orifice mitral valve. It mimics the mitral valve surgical technique known as “edge-to-edge” repair, or Alfieri’s stitch, which was introduced in the 1990s.5 The MitraClip system involves the insertion of a clip into the left atrium through transseptal access to approximate the free edge of the mitral leaflets at the site of the regurgitant jet.1,6 The MitraClip device is placed without the need for arresting the heart or cardiopulmonary bypass.7
Treatment of both degenerative and functional MR with the MitraClip has been shown to result in negligible intraprocedural mortality, low periprocedural complications, and a successful outcome in reduction in MR, according to a data analysis of contemporary literature recently published in the Journal of Thoracic Disease.4 MitraClip was approved by the US Food and Drug Administration (FDA) for treatment of patients with significant symptomatic degenerative MR who are at prohibitive risk for surgery in October 2013.