Restenosis, as the process is known, is a huge problem. Doctors already routinely use a two-pronged approach to treat blocked coronary arteries. In angioplasty, a balloon at the tip of a catheter is inflated to widen the blocked coronary artery and improve blood flow. At the same time, doctors insert tiny coils called stents into the artery to keep it propped open. However, in 20 to 30 percent of patients, plaque-like blockages form within the stent, restricting blood flow.

Examining the efficacy of ultrasound in preventing restenosis
The new trial will attempt to find out if ultrasound will help prevent restenosis. The Jefferson team is working with a company, PharmaSonics Incorporated of Sunnyvale, Calif., to use ultrasound – or “sonotherapy” – immediately after angioplasty and stent insertion.

The new Phase II clinical trial, dubbed SWING, involves 60 centers in the United States, Canada and Brazil. Researchers at Jefferson plan to look at approximately 20 to 30 patients with newly found clogged arteries. In all, approximately 1,200 patients are expected to participate. One-half of the patients will receive angioplasty and stents to treat their clogged artery; the other half will receive angioplasty, stents and ultrasound.

Researchers hope to see at least 30 percent fewer “major cardiac events” – including angina, heart attack, new bypass surgery, angioplasty, and death – over nine months, says Michael Savage, MD, Associate Professor of Medicine at Jefferson Medical College of Thomas Jefferson University and director of the Cardiac Catheterization Laboratory at Thomas Jefferson University Hospital.

“We hope it will be another technology to further reduce restenosis,” says Dr. Savage, who along with David Fischman, MD, Director of Jefferson’s Core Angiography Laboratory in the Division of Cardiology and Associate Professor of Medicine at Jefferson Medical College of Thomas Jefferson University, leads the Jefferson team. It will soon begin a new trial aimed at patients who already suffer from restenosis. They will test the effectiveness of ultrasound in clearing away plaque from inside the artery, similar to the way radiation has begun being used.

Assessing complication rate
Dr. Savage hopes ultrasound will have fewer potential complications than radiation, which was recently approved by the Food and Drug Administration for use with angioplasty in treating and preventing restenosis. Sonotherapy is logistically simpler because it does not involve ionizing radiation and in contrast to brachytherapy, does not require a radiation oncologist and radiation physicist to be present. Sonotherapy takes only 10 minutes in the average patient.

“Using ultrasound in this way could be a breakthrough,” says Dr. Savage. “It will be exciting if it works.”