People who undergo mitral valve surgery and also have less than severe leakage of the tricuspid valve may benefit from having both valves repaired at the same time, according to a new international study of more than 400 adults, which found that simultaneous repair decreased the risk of future severe leakage of the tricuspid valve.

“There’s a general agreement among surgeons that if there is severe leakage of the tricuspid valve, then we should fix it,” says Johns Hopkins cardiologist James Gammie, co-director of the Heart and Vascular Institute. “However, there has been considerable uncertainty as to whether the tricuspid valve needs repair at the time of mitral valve surgery when the leakage is only moderate or less.”

To study the potential effectiveness and safety of less than moderate tricuspid valve repair during mitral valve surgery, researchers conducted an international randomized controlled trial at 39 locations across the U.S., Canada and Germany between 2016 and 2018. A total of 401 adults were included in the study; 203 had only the mitral valve operation, while 198 had mitral valve surgery plus tricuspid valve repair.

After a two-year follow-up of participants, the researchers found that, overall, those who had both their mitral valve and their tricuspid valve problem repaired at the same time experienced better outcomes, such as less progression to moderate or severe leakage and improved treatment success than those who had only their mitral valve repaired. The team published their results in November in The New England Journal of Medicine.

Among the team’s key findings: Only 3.4 percent of people who had both valves repaired progressed to moderate or severe tricuspid regurgitation after two years, compared with 25 percent of those who had the mitral valve surgery alone.

The researchers also found disadvantages, Gammie notes. The addition of tricuspid valve repair prolonged the length of surgery time and time spent on a heart-lung machine by 34 minutes. Patients had a longer median hospital stay by two days. And permanent pacemakers were needed in 14% of patients in the tricuspid valve repair group compared with 2.5% of patients who had the mitral-only surgery. (Researchers note this did not appear to have a negative impact on patients.)

“We clearly need to better understand the risk factors for needing a permanent pacemaker implanted after tricuspid valve repair and how to best mitigate the risk with technique modifications or different postoperative management strategies,” says Gammie.

“But for the first time, we have high-level evidence to help us understand what to do in the operating room when it comes to tricuspid valve repair in those with less than severe regurgitation.”