By Kim O’Brien Root
A research trial being conducted at Sentara Heart Hospital in Norfolk is testing a device that could be a major advance in cardiology.
The device is a dissolvable stent that would replace the metallic stents that have been used by doctors for decades to treat blockages in the heart vessels. While metal stents are effective in treating coronary heart disease, this next generation of stents is being seen as a major advance.
Stents are tiny tubes, usually made of metal mesh, that expand to open blocked vessels and restore blood flow to the heart. They’re used to reduce chest pain and treat heart attacks. But these tiny little scaffolds aren’t needed indefinitely—just long enough for the artery to remake itself into a normal artery, according to Dr. Paul Mahoney, a cardiologist and the principal investor for the Sentara study.
Unlike metal stents that remain in the blood vessel, potentially causing clots and limiting further chances to fix the artery through surgery, dissolvable stents are absorbed into the body over time.
The placement of metal stents means that a patient has to be on blood thinning medication such as aspirin or Plavix, and new clots can sometimes form in the stent. The use of a dissolvable stent could mean less time a patient has to be on blood thinners and make it safer to do other heart procedures, Mahoney says.
“Stents themselves were a major advance,” Mahoney said. “Drug-coated stents were a major advance. This would be another major advance in cardiology.”
Coronary artery disease is the leading cause of death in men and women in the United States, with about 785,000 Americans having a first heart attack every year.
The dissolvable stents—called Absorb—are made of a bioresorbable polymer, the same substance used in dissolving sutures. The stents remain rigid for four to six months, and gradually are metabolized by the body and absorbed over 12 to 18 months, returning the vessel to a more natural state. They’ve been used in Europe for about five years, Mahoney says.
Sentara Cardiovascular Research Institute began enrolling heart patients in the study in May, joining about 20 other medical facilities around the country taking part in this clinical research trial. The study is designed to test the safety and effectiveness of the new stents as compared to the current medicated metallic stents, which are called drug-eluting stents.
Stents placed in the coronary blood vessels deliver a medication called everolimus, an immunosuppressant that helps prevent the vessel from narrowing. The new dissolvable stent also carries this medication.
The pivotal trial is the last step in determining whether the Federal Drug Administration approves the new stents for use in the U.S. The health care company Abbott sponsors the trial.
About 2,250 patients are expected to be enrolled in the double-blind study by the end of the year, including about 200 at Sentara Heart Hospital. Half of the patients will receive the new dissolvable stent, while the other half receives a metal stent. The results of the two groups will then be compared.
The study is estimated to be completed by 2018, according to www.clinicaltrials.gov. Sentara Heart Hospital is the only medical facility in southern Virginia participating in the study.
“It’s very exciting,” said Chelle Zulick, a registered nurse and research coordinator with Sentara Cardiovascular Research Institute. “It’s the next generation. It’s really moving into a new era of a stent.”
Only one local patient has been enrolled in the study so far, Mahoney says. The patient, a man in his 50s who had been experiencing chest pain, received the stent about three weeks ago and is doing well, he says
Just like a metal stent, the dissolvable stent is inserted using a catheter and balloon during a procedure called an angioplasty.
Anyone interested in participating in the study can contact the Sentara Cardiovascular Research Institute at 757-388-5480. Participants must be at least 18 years old and have some blockages in the vessels leading to the heart. Sentara will conduct a screening to determine a person’s eligibility.