Emory Report

 December 1, 1997

 Volume 50, No. 14

Study finds arteries remain
clear 6 months after radiation

Coronary arteries remain open six months after mild irradiation in 90 percent of postangioplasty patients, reported Emory's Spencer King, principal investigator for "Beta Radiation for Restenosis Trial" (BERT-1), at the American Heart Association Scientific Sessions Nov. 10.

These findings suggest radiation treatment blocks restenosis-the process by which coronary arteries widened by balloon angioplasty eventually renarrow. BERT-1 is the first human trial to test the use of low doses of locally delivered beta radiation for preventing restenosis, which occurs in about one-third of patients who undergo angioplasty. A phase III clinical trial based on BERT-1 preliminary data is now evaluating the technique in 1,100 patients at 26 medical centers in North America and Europe.

During the study, specially fitted catheters delivered minute amounts of radiation to angioplasty sites in the coronary arteries of 35 patients. The researchers measured the diameter of vessel openings before angioplasty, just after angioplasty and at six months' followup. Subjects' vessels were, on average, 73 percent closed before angioplasty, 25 percent closed just after angioplasty and 25 percent closed at the six-month followup.

The increase noted in the diameter of the vessel's opening several months after angioplasty when compared to the opening just after angioplasty is referred to as "late loss." The team found radiation reduced the late loss and late-loss index by 85-90 percent.

"Using this system, intracoronary beta radiation was feasible without disrupting the normal [cardiac catheterization] lab routine or producing complications," King and his colleagues reported. "As illustrated, the usual late loss was eliminated in most patients."

During angioplasty, a balloon-tipped catheter is threaded through arteries. As the balloon expands, it pushes plaque against vessel walls and frees blood flow. Unfortunately, that same lifesaving procedure (as well as the use of tiny metal stents to prop open vessels) triggers an inflammatory response in about one-third of patients, putting them at risk for restenosis and further cardiac complications.

About 500,000 coronary angioplasties are performed domestically each year, and another 500,000 are performed annually outside the United States; so roughly 300,000 persons are at risk each year for restenosis after angioplasty. In the United States, repeat angioplasties cost billions of dollars.

King directs the Gruentzig Cardiovascular Disease Research Center and is professor of medicine at the School of Medicine. Other Emory researchers included Larry Klein, Ron Waxman, Keith Robinson, Kris Anderberg, Judy Scruby and Ian Crocker, all of the School of Medicine. BERT-1 was funded by the National Institutes of Health.

-Lorri Preston

Analyses show better recovery at lower costs

Sicker heart patients are more likely to survive coronary intervention, are spending less time in the hospital recovering and are doing better once at home-all this at about one-third the cost of similar care in the 1980s, according to cost benefit analyses presented by William Weintraub, associate professor of Medicine, at the American Heart Association Scientific Sessions, Nov. 11.

Weintraub and his Emory colleagues profiled all 12,265 patients who underwent coronary artery bypass graft surgery at Emory and Crawford Long hospitals from 1988-96 as well as all 12,978 patients who received balloon angioplasty at Emory from 1991-96. While the numbers of the two analyses differ, the trends uncovered do not.

The researchers report that hospital costs in 1996 dollars fell 30 percent in the coronary bypass surgery analysis (from mean per-procedure costs of $22,689 in 1988 to $15,987 in 1996). Other statistically significant changes noted during that time period indicate that patients were older and more likely to have high blood pressure, to have had a heart attack, to have diabetes and to have had congestive heart failure (6.5 to 7.9 percent). Death rates in the study population decreased from 4.7 to 2.7 percent.

"Over the last several years the patients have become sicker and by several measures outcome has improved," Weintraub reported. "These changes have been accomplished while at the same time resource use has decreased as measured by length of stay (down from 2.8 days in 1991 to 1.9 days in 1996) and cost. The decrease in cost was 26 percent, almost entirely in the last two years while stent utilization increased. Whether these favorable trends can continue or if care is already optimal remains to be seen." -L.P.

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