Study of Surgical Treatment of Mitral Valve Disease Suggests Need for Earlier Interventions
July 23, 2018—The Society of Thoracic Surgery (STS) announced the publication online of a study by James S. Gammie, MD, et al in The Annals of Thoracic Surgery suggesting that many patients do not undergo surgical intervention until it is too late to completely reverse damage caused by mitral valve disease.
In the STS announcement, Dr. Gammie, commented, “This study shows that a significant number of patients are still referred for mitral valve surgery later than they should be. In these cases, the malfunctioning mitral valve has caused significant damage to the heart and/or lungs, and while an operation can be performed, long-term outcomes will be compromised, to some extent.”
In the study data from the STS Adult Cardiac Surgery Database were analyzed to determine trends related to current mitral valve operations in North America. The database contains more than 6.5 million cardiac surgery procedure records, representing more than 90% of all adult cardiac surgery hospitals in the United States and Canada.
As reported by STS, the investigators identified 87,214 patients at 1,125 centers who had isolated primary mitral valve operations from July 2011 to September 2016. The average age of patients in this group was 64 years; half were female. During the study period, the number of mitral valve operations performed per year increased by 24%, from 14,442 in 2011 to 17,907 in 2016, with a 44% increase in primary mitral operations performed for degenerative disease.
Study investigator Vinay Badhwar explained in the STS press release, “This suggests that the mitral valve disease may have reached a chronic stage prior to referral for operation, which means that heart and lung damage may not be fully reversible. In these patients, their symptoms may improve after surgery, but their life expectancy may be reduced.”
Dr. Badhwar continued, “Once the leakage is severe, heart damage may result, thus mitral valve operation is recommended. The preferred operation is mitral repair, whenever possible. If performed in a timely manner, the patient’s heart function and life expectancy may return to normal.”
According to the STS, the study showed that the overall repair rate was 65.6% (57,244) and the replacement rate was 34.4% (29,970). Overall operative mortality was 2% (1,762).
Dr. Gammie stated, “We found that the number of operations performed for mitral valve disease is growing faster than any other category of heart operation and that the results were excellent with low risks of death and complications.”
Additionally, the investigators noted that while the prevalence of mitral valve disease and the number of mitral valve operations performed per year are increasing, overall aortic valve operations were performed 1.6 times more commonly than mitral valve operations during the study period. Dr. Gammie commented, "This may suggest important underreferral and undertreatment of mitral valve disease, which may be related to the slower progression of signs and symptoms of mitral compared to aortic disease, as well as potential lack of adherence to guidelines for intervention.” He concluded, “So although contemporary outcomes are excellent, there remains an important and substantial opportunity to improve results for patients with mitral valve disease by following established guidelines and encouraging earlier referral for operation.”