Moderate-to-severe and severe mitral regurgitation (MR) are significantly associated with a heightened risk of death among older patients with heart failure with preserved ejection fraction (HFpEF), according to new findings published in the American Journal of Cardiology.[1]
“Numerous echocardiographic and cardiac catheterization studies have demonstrated that the presence and degree of MR are associated with poor outcomes in HF with reduced ejection fraction (HFrEF),” wrote first author Ginger Y. Jiang, MD, with the Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology in Boston, and colleagues. Furthermore, recent trials have demonstrated that reducing MR through transcatheter mitral valve repair decreases mortality in patients with MR and HFrEF. Despite these encouraging results, it remains uncertain whether MR severity is similarly associated with mortality in the case of HFpEF.”
Jiang et al. started with data from more than 53,000 Medicare patients who were referred to a single high-volume facility for transthoracic echocardiography (TTE) from 2003 to 2017. To account for patients who may be eligible for Medicare due to disability and not age, any patients younger than 65 years old were excluded from the team’s analysis. Patients with evidence of endocarditis, missing MR severity data or no prior history of heart failure were also excluded. The group examined several variables—including age, blood pressure, heart rate and image quality—for each patients, grading the severity of any MR and tricuspid regurgitation using American Society of Echocardiography-recommended guidelines.
After all necessary exclusions, the researchers had a cohort of 7,778 patients. The mean patient age was 75.7 years old, and 55.9% were women. The median follow-up period was 8.1 years.
While a majority (81.4%) of patients had no MR or mild MR, 16.2% had moderate MR and another 2.4% had moderate-to-severe or severe MR. Overall, after adjusting for multiple variables, moderate-to-severe MR and severe MR were both linked to a significantly higher risk of all-cause mortality. For example, after one year, 15.8% of patients with moderate-to-severe MR or severe MR had died compared to 10.5% of patients with no, mild or moderate MR.
There were exceptions to this trend: patients with atrial fibrillation (AFib) and those with a recent heart failure hospitalization.
“Reasons for the lack of prognostic significance of atrial functional MR in this setting are uncertain,” the authors wrote. “They may reflect differences in the adaptation of the left atrium to volume loading that may be prognostically important. However, future studies should confirm and explore this hypothesis further.”
Another key takeaway from the team’s research was that just 0.9% of patients underwent mitral valve annuloplasty, replacement or repair. This included 24 mitral valve annuloplasties, 15 mitral valve repairs and 33 mitral valve replacements at a median of 19 days after TTE.
The low number of patients being selected for annuloplasties, mitral valve repairs and mitral valve replacements—just 16.4% of patients with moderate-to-severe MR and HFpEF underwent a mitral valve surgery within 10 years—suggested to the authors that there is still uncertainty about the benefits of such interventions.
“Further studies are needed to assess the role of MR reduction in mitigating the risk of mortality,” the group concluded.
Additional mitral valve content is available here.
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.