Atrial functional mitral regurgitation: Surgery improves outcomes more than medical therapy alone
![Treating atrial functional mitral regurgitation (AFMR) with surgery may be more beneficial than medical therapy alone, according to new data published in JAMA Network Open.[1]](/sites/default/files/styles/top_stories/public/2024-08/screenshot_2024-08-22_at_3.41.23_pm.png.webp?itok=ehrG9Z-m)
Treating atrial functional mitral regurgitation (AFMR) with surgery may be more beneficial than medical therapy alone, according to new data published in JAMA Network Open.[1]
AFMR, a type of mitral regurgitation (MR) defined by the lack of mitral valve pathology and normal left ventricular function, is typically seen in patients with chronic atrial fibrillation (AFib) or heart failure with preserved ejection fraction (HFpEF). While it has received an increasing amount of attention in recent years, there is still only limited outcomes data on different treatment strategies.
The study’s authors hoped to learn more, tracking data from more than 177,000 patients who underwent transthoracic echocardiography in Japan in 2019. For the sake of this study, the group defined AFMR as preserved left ventricular function (ejection fraction equal to or more than 50%) and a dilated left atrium. Patients were not categorized as having AFMR if they presented with degenerative changes in their mitral valve, MR due to systolic anterior motion of the mitral valve or MR subsequent to mitral valve surgery. Patients were also excluded if in the acute phase of decompensated heart failure.
The study’s final cohort landed at 1,007 AFMR patients. These patients tended to be older, with a mean age of 77.8 years old, and 55.7% were women. A majority of patients presented with a history of AFib.
While 113 AFMR patients underwent mitral valve surgery, the other 894 were treated with medical therapy only. Patients in the surgery group were significantly younger—mean ages of 73.8 years old vs. 78.3 years old—and were more likely to present with New York Heart Association class III or IV heart failure, permanent AFib or severe MR. Surgery patients also had a significantly larger mean left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left atrium diameter and left atrium volume index. Also, 60.2% of surgery patients underwent a mitral valve repair procedure, and the other 39.8% underwent a full mitral valve replacement. A significant number (8.4%) of surgery patients underwent a tricuspid valve surgery at the same time.
Overall, during a median follow-up period of nearly three years, the study’s primary outcome—heart failure hospitalizations and all-cause mortality—was seen in 18.3% of patients who underwent surgery and 33.3% of patients treated with medical therapy alone. The relationship between surgery patients and a reduced risk of the primary outcome remains even after making certain adjustments and exclusions.
Also, the authors noted, the surgery patients were the only ones linked to a decrease in natriuretic peptide levels at follow-up.
“The study showed that patients with AFMR generally have poor prognoses, but those who underwent mitral valve surgery had significantly better outcomes,” lead author Nobuyuki Kagiyama, MD, PhD, an associate professor at untendo University Graduate School of Medicine in Japan, said in a statement. “These findings underscore the importance of understanding AFMR and its treatment options. We believe this study provides critical insights into the real-world characteristics and treatment strategies for AFMR, paving the way for future trials to explore causal relationships and optimize patient care.”
Read the full study in JAMA Network Open here.
Read more about AFMR, as originally seen in JACC: Cardiovascular Imaging, here.
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.