[April 09, 2014]

John Muir Health Studying Next Generation Treatment for Blocked Arteries Using a Dissolvable Scaffold

John Muir Health is one of a very select group of health systems across the country participating in a clinical trial of a medical device that could change the way people are treated for coronary artery disease, which is the narrowing of one or more arteries that supply blood to the heart.

The ABSORB III clinical trial is focused on a new type of medical device called a bioresorbable vascular scaffold (BVS), similar to a stent, that is used to open blocked arteries and leaves no foreign body inside the patient except two tiny markers to identify where the device was originally placed.

"This is the Holy Grail of interventional cardiology," said Gary Gershony, M.D., interventional cardiologist and director of cardiovascular research, education and technology at John Muir Health's Cardiovascular Institute. "It's something that we dreamt about being able to offer patients for more than 20 years."

The device, called Absorb and made by healthcare company Abbott, works much like its metallic counterpart, which is currently the standard of care. Absorb opens a blocked artery and allows blood to flow through to the heart. Also like a medicated metallic stent, the BVS delivers medications intended to prevent the artery from scarring and re-narrowing.

Unlike the current stents in use, however, the BVS is made of polylactide, a naturally dissolvable material that is commonly used in medical implants like dissolving sutures, so that it dissolves harmlessly, becoming water and carbon dioxide over time. This process has the potential to allow the artery to regain motion -- expanding and contracting in response to normal activities such as exercise.

In the 1970s, patients underwent open heart surgery for artery blockages, which meant a long recovery. Treatment then evolved into balloon angioplasty, but with unpredictable results. In the late 1980s and early 1990s, bare metal stents implanted usin minimally invasive techniques became the standard with more positive results, but re-narrowing of arteries occurred 20-30% of the time. In 2003, drug eluting stents reduced that rate to less than 10%, but patients still have a permanent metal stent in their heart. A dissolvable stent is the latest innovation being tested for the treatment of blocked arteries.

"This has the potential to be the next quantum leap in interventional cardiology," Dr. Gershony said. "Even though patients don't know which stent they are receiving, they are excited to be part of the study and have a chance to receive something that won't remain in their body indefinitely."

The BVS dissolves completely except for two pairs of tiny metallic markers, which help guide placement and remain in the artery to enable a physician to see where the device was placed. From a patient perspective, the procedure that involves the new dissolvable scaffold is similar to the procedure used to place the older metallic stents. Both are placed using a minimally invasive surgical technique called percutaneous coronary intervention (PCI (News - Alert)), which involves inserting a catheter through a small opening in a patient's groin or wrist. The stent is crimped onto a deflated balloon at the end of the catheter and moved into position at the blockage site where the balloon and stent are expanded. Once the stent is placed, the balloon is deflated and the catheter is removed. Patients generally spend a night in the hospital for observation and are released the next day.

The BVS has been studied and approved in Europe, as well as parts of Asia and Latin America, but ABSORB III is the first major clinical trial in the United States. It is a multi-hospital, randomized, controlled trial eventually involving approximately 2,250 patients across the country. The U.S. Food and Drug Administration (FDA) will review the trial data after one year results are available and consider approval. If approved by the FDA, the device will be the first bioresorbable scaffold available in the United States.

John Muir Health has been involved in the study since August of 2013 and has so far enrolled 18 patients. Patients interested in the trial who meet the clinical inclusion criteria should consult with their cardiologist about participating. More information is also available by calling the John Muir Health Clinical Research Center at (925) 674-2580.

Coronary Artery Disease is a leading cause of death for men and women in the United States. According to the Centers for Disease Control, each year, about 785,000 Americans have a first heart attack. Another 470,000 who have already experienced one or more heart attacks will have another. Heart disease accounts for one of every six deaths that take place in the United States.

About John Muir Health

John Muir Health is a nationally recognized, not-for-profit health care organization east of San Francisco serving patients in Contra Costa, eastern Alameda and southern Solano Counties. It includes a network of 950 primary care and specialty physicians, more than 5,500 employees, medical centers in Concord and Walnut Creek, including the county's only trauma center, and a Behavioral Health Center. The health system also offers a full-range of medical services, including primary care, outpatient and imaging services, and is widely recognized as a leader in many specialties - neurosciences, orthopedic, cancer, cardiovascular, emergency and high-risk obstetrics care. For more information, visit johnmuirhealth.com.

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