A heart stent is a simple piece of technology: a collapsed metal tube a little bigger than a spring in a ballpoint pen. The idea behind its use in heart care is simple too: The stent is inserted into a blocked vein or artery and expanded to hold the passage open and allow blood to flow.
But like many procedures dealing with the human body, it’s more complicated than that. The body’s natural response is to fight foreign objects, and researchers have worked for years to craft a stent that would assimilate into the body with few negative affects. Now, as part of an international study taking place at the Louisiana Heart Hospital in Lacombe, doctors hope a new design and coating will reduce the post-op treatment regimen for patients and significantly improve their quality of life.
When first introduced, stents were bare pieces of metal. When doctors inserted them into patients’ arteries, scar tissue would build up around the stents, gradually closing off the vessels. In 2002, the FDA approved a new generation of stents coated with drugs to prevent the buildup of scar tissue. Those, however, can cause blood clots to form abruptly, blocking the stent and causing a heart attack.
Patients who have these scar-tissue-resistant stents are required to take an anti-clotting medication, such as Plavix, for a full year or more after the stent is inserted. That can be a problem for various reasons, including that other needed surgeries may have to be postponed while a patient is taking the medication.
Lewis Addison, a participant in the study at the Louisiana Heart Hospital, said he knew he needed a stent but was nervous about taking the anti-clotting medication.
“My dad bumped his head and he was on Plavix,” he recalled. “He had a bleed on his skull, and when they discovered it, it was still four days until they could do anything about it.”
The heart hospital study uses a new, thinner stent design by CeloNova that should be less prone to scar tissue. The stent is also coated with an anti-clotting medicine. If successful, the stent could reduce the required course of anti-clotting medication from one year to three months, said Pramod Menon, a cardiologist at the Heart Hospital who is the study’s principal investigator in Louisiana.
The new stent could be a “game changer,” he said, and critical for those who need other surgeries or who are at risk for bleeding.
The study, headed by Dr. Donald Cutlip at Beth Israel Deaconess Hospital at Harvard University, will include placing the stents in about 300 patients worldwide. The Louisiana Heart Hospital does about 800 stent procedures per year, Menon said.
Louisiana is a natural place for part of the trial: Heart disease is the No. 1 killer in the state and was responsible for one-quarter of all deaths in 2010, according to data from the American Heart Association.
If the trial — which is funded by the stent’s manufacturer — is successful, the results will be submitted to the Food and Drug Administration for approval.
Subsequent studies would be needed to determine if the course of anti-clotting medication could be shortened even further, Cutlip said.
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