New Treatment Could Help Fix the Heart’s ‘Forgotten Valve’
For the first time, patients with damaged tricuspid valves in their hearts might have a safe treatment that actually helps.
More than 1 million mostly older Americans have seriously leaking tricuspids, a valve on the right side of the heart that lets deoxygenated blood flow between the right atrium and the right ventricle. When the valve leaks, blood flows backward. As a result, fluid accumulates in vital organs while legs and feet get swollen. The eventual outcome is heart failure.
Patients’ symptoms often are severe — fatigue, abdominal distention, swollen legs and general feelings of malaise. Even their eyes can get swollen, said Dr. Gregg Stone, an interventional cardiologist at Icahn School of Medicine at Mount Sinai.
“Imagine a beach ball filled with fluid in your stomach all the time,” said Dr. Joseph Cleveland, Jr., a cardiothoracic surgeon at the University of Colorado School of Medicine.
Medicine to mitigate the injury causes perilous side effects, and surgical repair of the valve has usually been too dangerous to attempt.
Now the medical device company Abbott is reporting results from a clinical trial of a treatment that involves clipping the floppy tricuspid valve to make it smaller and better able to function. The clipping device used is similar to a successful one used to treat patients with damage to another part of the heart, the mitral valve.
The results were published Saturday in The New England Journal of Medicine to coincide with a presentation at the annual meeting of the American College of Cardiology. And patients may soon have a different option for treatment when another company, Edwards Lifesciences, completes a clinical trial of a different approach that is now underway.
For the study financed by Abbott, researchers report that the clip stopped much of the leakage and allowed many patients who had been debilitated by symptoms to get their lives back. “It’s really nice to see quality of life improvement,” said Dr. Cleveland, who was not involved in the Abbott trial. “This gives an option which is great.”
The treatment was also safe, with a less than one percent mortality risk in these very sick patients and, on average, a one day hospital stay. The price of the procedure is not yet known.
Patients in the Abbott study have now been followed for at least one year. The clip did not extend life but, said Dr. David Adams, cardiac surgeon in chief at Mount Sinai Health System and co-principal investigator for the study, “we would never see a mortality difference — one year was not enough time.”
“This is a huge win,” said Dr. Kendra Grubb, a heart surgeon and director of the structural heart center at Emory University who was not involved in the study. She added that although doctors have been able to keep patients alive with medical therapy, “it’s a miserable way to live.”
The clinical trial by Edwards is testing a different method. It replaces the tricuspid valve by threading a new valve into the heart, pushing aside the old in a manner similar to a method called transcatheter aortic valve replacement. The aorta controls blood flow from the heart, and the TAVR method has been used to replace the valves of hundreds of thousands of patients.
The developments come after years of inattention to the tricuspid problem. The valve was long known as the forgotten valve. Cardiologists had assumed that if they fixed problems on the left side of the heart — like a leaky mitral or aortic valve — the tricuspid valve would fix itself.
Their assumption was wrong.
Patients and cardiologists have long sought an effective treatment for tricuspid leakage. The only medical treatment today is with drugs called loop diuretics. They flush excess fluid out of patients’ body, but only temporarily. As the diuretic treatment is repeated, patients’ fluid retention gets worse and worse until the kidneys fail and eventually even the tricuspid valve itself gets engorged with fluids.
“Patients get more and more miserable,” said Dr. Paul Sorjja chairman of the valve science center at the Minnesota Heart Institute Foundation and co-principal investigator for the Abbott study.
Few attempt surgery, which is used to repair — not replace — the delicate valve. Most patients have so many other medical problems, often stemming from their tricuspid leakage, that an open-heart surgery would be too risky. The death rate from surgery is 10 percent, which is 10 times higher than the rate with aortic valve replacement.
The Abbott study involved 350 patients with an average age of 78 who had debilitating valve leakage, also known as regurgitation, ranging from valve failure classified as severe to what is known as torrential regurgitation. They were randomly assigned to the clip or to medical therapy with a loop diuretic.
A month after having the clip implanted, 87 percent of patients’ tricuspid regurgitation had been downgraded to mild or moderate as compared to 4.8 percent in the group getting loop diuretics.
Patients who got the clip said their disabling symptoms receded and they could enjoy life again.
“I felt better immediately,” said Adelaide Effertz, 86, who lives on a farm in Pine City, Minn., and was one of the first patients treated in the study. “It’s just wonderful.”
She says she no longer has the intense and unrelenting fatigue that forced her to nap a couple of times each afternoon.
If the Edwards valve replacement study is successful and both it and the Abbott clip receive regulatory approval, some patients may face a dilemma over which procedure they should have. If they choose the clip they cannot have the replacement later, because it would impede the process of pushing the old valve aside, said Dr. Howard Herrmann, director of interventional cardiology at the University of Pennsylvania, who enrolled patients in the Abbott trial.
That, though, is a good dilemma to have for patients who have had almost nothing.
“It’s an exciting beginning,” Dr. Adams said.