According to the Global Burden of Disease study, the prevalence of degenerative mitral valve disease has more than doubled over the past three decades, making mitral valve (MV) regurgitation one of the most common forms of valve disease in the world. Clinical guidelines recommend mitral valve repair over mitral valve replacement to treat MV regurgitation, but research published in JAMA Network Open shows repair rates have been on the decline in the U.S. for the treatment of anterior mitral leaflet regurgitation.
Stephanie Mick, M.D., director of robotic and minimally invasive cardiac surgery at NewYork-Presbyterian and Weill Cornell Medicine, is the senior author of the study, which identified repair and replacement trends in the U.S. for isolated anterior mitral leaflet prolapse, a less common cause of mitral regurgitation than posterior leaflet or bileaflet prolapse. Because of its rarity and differences in pathology, anterior leaflet regurgitation can be more technically challenging to treat, and anterior leaflet repair is thought to be less durable than in posterior leaflet repairs.
However, “the goal for degenerative mitral valve pathology is to repair the valve, because that is associated with the longest durability and lowest risk for the patient,” Dr. Mick says. “Repair rates have improved over time for the posterior leaflet, so we expected the same for the anterior leaflet. Instead, it was becoming disturbingly less common. Our study is one of the largest to examine trends in treating isolated anterior leaflet regurgitation, and the findings have real implications for clinical practice.”
Our study is one of the largest to examine trends in treating isolated anterior leaflet regurgitation, and the findings have real implications for clinical practice.
— Dr. Stephanie Mick
The Prevalence of Mitral Valve Repair for Anterior Leaflet Regurgitation
To assess how frequently mitral valve repair or replacement on the anterior leaflet was being performed, Dr. Mick and her team analyzed data over a 10-year period from the Society of Thoracic Surgeons’ Adult Cardiac Surgery Database, focusing on 16,259 individuals diagnosed with isolated anterior mitral leaflet regurgitation who underwent either MV surgical repair or replacement. The repair techniques included leaflet resection, placement of neochordae, edge-to-edge MV repair (Alfieri stitch), and chordal transfer, either in combination with annuloplasty or as standalone annuloplasty using a band or ring.
Among the research team’s findings:
- Overall, 55.6% of anterior leaflet regurgitation patients had mitral valve repair
- 44.4% of patients underwent mitral valve replacement
- Anterior leaflet repair rates declined from 58% in 2011 to 51.6% in 2022
- Annuloplasty (used alone or with another technique) was performed in almost 89% of repairs; however, its use as a sole method of repair has been on a downward trend
- The top forms of repair were neochord placement (40%), annuloplasty alone (32.8%), and leaflet resection (10%).
Dr. Mick was particularly surprised to find that in nearly 82% of MV replacement procedures, there was no initial attempt at repair. “Sometimes in the operating room, you may find that the repair didn’t work, leading to a re-repair or ultimately, a valve replacement,” she says. “However, in most of these replacements, there was not even an attempt at repair. That suggested to me that the surgeons may not have known how to repair isolated anterior leaflet pathology or perhaps didn’t trust the durability of repair, and so just went straight to replacement.”
An example of isolated anterior leaflet pathology at the time of robotic repair.
Although morbidity and mortality improved over the 10-year period for both repair and replacement, mitral valve repair reported better outcomes overall. By 2022, operative mortality was 2% for MV repair versus 5.2% for MV replacement, while operative morbidity and mortality was 18% versus 34.9%, respectively. “Mitral valve repairs can last a lifetime,” says Dr. Mick. “But if you have a replacement when you’re relatively young, it is very likely to mean that you’ll need another valve procedure later in life.”
Leveraging Expertise in Mitral Valve Repair for Better Patient Outcomes
Dr. Mick says the findings underscore the importance of patients receiving care at surgical centers with the most experience in treating anterior leaflet cases. In the study’s cohort, the median annual hospital volume for anterior cases was low, but patients who went to a high-volume center were more likely to receive MV repair.
Patients should be treated at high-volume mitral valve repair centers to maximize their chances of receiving a repair rather than a replacement.
— Dr. Stephanie Mick
“What often happens is that a patient is referred to a low-volume center that doesn’t perform many mitral valve repairs, which means the surgeons may not be as experienced in performing anterior leaflet repairs,” says Dr. Mick. “Patients should be treated at high-volume mitral valve repair centers to maximize their chances of receiving a repair rather than a replacement.”
Another significant finding: Only 13.1% of cases were performed minimally invasively, with only 4.6% being robotic mitral valve surgery. “What we found interesting was that if a patient did undergo a minimally invasive approach, they were more likely to have had a repair than the rest of the population,” adds Dr. Mick. “Our theory was that the centers doing minimally invasive mitral valve surgery were also high-volume centers with more experience in these techniques. For instance, if I’m seeing a patient with an isolated anterior leaflet problem, they will almost certainly undergo a minimally invasive approach with a very high rate of repair.”
Ultimately, the study reveals a gap in knowledge among clinicians for how to approach treatment for isolated anterior mitral leaflet regurgitation. “Because issues in the anterior leaflet are not as prevalent, they aren’t discussed as often. This is a blind spot we need to overcome,” says Dr. Mick. “With this study, we wanted to highlight awareness that there is a difference in pathology between regurgitation coming from the anterior versus posterior leaflet, and that patients can benefit from receiving care from experienced mitral valve specialists.”
