Clinical trial being conducted at Rush-Presbyterian-St. Luke's Medical Center
A clinical trial on a procedure that delivers radiation to arteries to prevent them from re-closing after patients are treated with angioplasty and stenting has been so successful that the Food and Drug Administration (FDA) announced that the trial can be expanded. Now, cardiologists at Rush-Presbyterian-St. Luke's Medical Center, who were among the original investigators in the clinical trial, can treat all patients who met the enrollment criteria for the clinical trial with the low-dose radiation. In the clinical trial begun two years ago, patients enrolled were given either radiation or standard angioplasty to treat arteries that reclosed (restenosis) after prior angioplasty or stenting. Stents are spring-like devices that keep blood vessels open that might otherwise close after angioplasty. With the FDA approved expansion, many patients with restenosis can now receive the radiation. Restenosis is the primary limitation of current therapies used to open blocked arteries.
Studies show that 30-50 percent of people who undergo angioplasty to open blocked arteries may experience restenosis within six months of the procedure. "The initial phase of the research trial showed a dramatic 66 percent reduction in in-stent restenonsis, documented by angiography," said Dr. Gary Schaer, co-principal investigator and director of the cardiac catheterization laboratory at Rush. Dr. Schaer is co-principal investigator along with Dr. Jeffrey Snell.
"This re-narrowing happens because cells in the artery wall divide and proliferate as a healing response to the injury caused by the angioplasty balloon or stent placement. Low-dose local radiation therapy actually inhibits the cells' ability to respond in this way, thereby substantially reducing the re-narrowing response," Schaer said.
During angioplasty, a cardiologist threads a balloon catheter through the femoral artery - accessed in the thigh - to the coronary artery in the heart. Once the catheter is positioned at the site of the blockage, the balloon is expanded, pressing plaque against the artery wall to open the artery and restore blood flow.
Immediately after the balloon procedure, cardiologists use the Beta-Cath System to advance tiny metal beads within the catheter to the section of artery previously opened by the balloon catheter. The metal beads emit beta radiation to the inside of the artery for fewer than five minutes and are then withdrawn from the body. The amount of radiation exposure is considerably less than what a patient would receive during a chest x-ray.
The Beta Cath device could reduce the need for bypass surgery or other cardiac treatment procedures for people with coronary artery disease, according to cardiologists at Rush. Rush is one of 50 sites nationwide participating in a clinical trial testing the safety and efficacy of the device under direction of the FDA.
"Rush is in a good position to offer this promising new treatment because we have performed well over 100 Beta Cath procedures," Snell said. More than 13 million people in the United States have been diagnosed with coronary artery disease, the leading cause of death in this country. This year alone, an estimated 1.8 million patients will undergo procedures such as coronary bypass surgery and balloon angioplasty to reopen their arteries.
Rush-Presbyterian-St. Luke's Medical Center includes the 809-bed Presbyterian-St. Luke's Hospital; 154-bed Johnston R. Bowman Health Center for the Elderly; Rush University (Rush Medical College, College of Nursing, College of Health Sciences and Graduate College); and seven Rush Institutes providing diagnosis, treatment and research into leading health problems. The medical center is the tertiary hub of the Rush System for Health, a comprehensive healthcare system capable of serving about two million people through its outpatient facilities and five member hospitals.