by Matt Scanlan

Researchers may be on the trail of a new weapon in the war against heart disease _ antibiotics.

Evidence that a bacterial infection may play a role in heart disease is prompting researchers at Vanderbilt University Medical Center to investigate whether antibiotics can protect heart attack survivors from having another one.

Cardiologists at VUMC are participating in a multi-center study of the antibiotic azithromycin as a potential means to keep coronary artery disease in check in people who have had heart attacks.

"This stimulates a whole new area in heart disease prevention that could be very important," said Dr. David J. Maron, assistant professor of medicine, one of the VUMC investigators in the study.

"It's also important because of the simplicity and the safety of the treatment."

Maron's co-investigators in the study _ dubbed WIZARD for Weekly Intervention with Zithromax for Atherosclerosis and its Related Disorders _ are Drs. John H. Dixon Jr., associate clinical professor of medicine; F. Andrew Gaffney, professor of medicine; and William B. Hillegass Jr., assistant professor of medicine.

Cardiovascular disease which affects about 50 million Americans, is the most common cause of death in the United States. Heart attacks claim more than 925,000 American lives each year. There are about 11.2 million survivors of heart attacks.

It is believed that atherosclerosis, the build up of cholesterol plaque that narrows the arteries, results from an inflammatory response to injury of the lining of these blood vessels, Maron said.

"That injury can result from several things, including the `bad cholesterol' LDL, high blood pressure, cigarette smoking, diabetes and a chemical process known as oxidation," Maron said.

More than 10 years ago, it was proposed in medical literature that an infectious agent could be one of the causes of artery wall injury. The bacteria Chlamydia pneumoniae has since been implicated as a cause of atherosclerosis. Studies have found evidence of C. pneumoniae in the arteries of people with atherosclerosis.

A study reported earlier this year in the journal Circulation demonstrated that azithromycin reduced the risk of subsequent cardiovascular events among men who had survived a heart attack and who had evidence of infection with C. pneumoniae.

Reducing the inflammatory response initiated or perpetuated by the bacterial infection may be the key, Maron said.

"Anything that can initiate or perpetuate inflammation in the artery wall may be a factor in atherosclerosis, and anything that will reduce that response may help," Maron said.

The WIZARD study will include a total of 3,300 adults who have had a heart attack at least six weeks earlier. The primary goal is to assess whether azithromycin is effective in preventing the progression of clinical cardiovascular disease in this group. This would include such "events" as unstable angina requiring hospitalization, a subsequent heart attack, the need for a revascularization procedure such as bypass surgery or angioplasty and death.

A secondary goal will be to assess prevention of other cardiovascular events such as stroke, transient ischemic attacks, peripheral vascular disease and congestive heart failure.

For more information about the WIZARD trial, call 343-1700.