On November 25, UCLA Health System announced that it is seeking patients with heart disease for a study that will compare safety and effectiveness of absorbable and metallic stents. Specifically, UCLA researchers are seeking patients with coronary artery disease who are scheduled to undergo interventional coronary artery procedures. The study will compare the safety and effectiveness of Absorb, a naturally dissolving stent that is an investigational device in the United States, with XIENCE, an already-approved commercially available metallic stent.
The researchers will enroll approximately 3,000 subjects at 140 US sites and will follow patients for five to seven years. Coronary arteries are the main blood vessels that supply oxygen and nutrients to the heart; they sometimes become narrowed, which restricts blood flow to the heart and can cause chest pain and other symptoms.
To increase the blood flow through a narrowed heart artery, doctors can perform a procedure called an angioplasty, in which a balloon is inserted and temporarily inflated where the artery is narrowed or blocked. The balloon pushes the blockage against the artery wall and opens up the heart artery to improve blood flow to the heart. The procedure is often followed by the placement of a drug-releasing stent, which is a small metal mesh tube coated with medication, in the narrowed area of the artery to help keep the artery open and decrease the chance of the artery narrowing again. The stent stays in the heart artery wall permanently.
In this study, XIENCE, an FDA-approved drug-eluting stent, will be compared to Absorb Bioresorbable Vascular Scaffold system, or Absorb BVS, a temporary device that functions like a drug-releasing stent but is not made out of metal. “Absorb is made of polylactide, a naturally dissolvable material that is commonly used in medical implants, such as dissolving sutures, and completely dissolve over time,” explained principal investigator Jonathan Tobis, MD, a clinical professor of cardiology at the David Geffen School of Medicine at UCLA. He added, “After two years, the artery heals and expands with each heartbeat, unlike after a metal stent is placed where the stented artery remains rigid. Over time, the BVS material will gradually break down and be resorbed into the artery wall, leaving behind no permanent implant. The absorbable stent is a combination of a scaffold that helps to keep the artery open and the drug everolimus mixed with a bioresorbable polymer that helps prevent re-narrowing of the heart arteries.”
Dr. William Suh, MD, assistant clinical professor of medicine in the division of cardiology at the Geffen School of Medicine, noted, “This may help determine whether there is benefit from the absorbable stent in decreasing the rate of the re-narrowing as well.” The study participants will be followed five to seven years, include a total of up to 10 visits after the study procedure including a telephone call or office visit after one, three, six, and nine months, and at the end of each year. Study volunteers will be randomly assigned to treatment. They will find out which device they have received only at the end of the study.
Before undergoing the procedure, the participants will complete an interview, blood tests, an electrocardiogram and a health assessment questionnaire. Women of childbearing potential will also undergo a pregnancy test. During the procedure, all study subjects will receive a coronary angiogram to look at the narrowed heart arteries and determine whether the volunteer can be registered in the study. Volunteers will meet with a registered dietician who will provide instruction in following an American Heart Association low-fat diet during the study.
The clinical trial is funded by the vascular business of Abbott, the maker of both devices. For more information and to discuss potential risks and benefits, please call the UCLA division of cardiology at 310-794-4797.