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. Dr. Grubb, who is on an advisory board for Abbott and is a speaker for Edwards, 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 Sorajja chairman of the valve science center at the Minneapolis 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.