STENTS: HEPARIN Stent Coatings 'Profoundly Decrease' Clotting, TRANILAST Inhibits Restenosis in Certain Porcine Arteries, DIABETICS Fare Worse than Nondiabetics After Stenting

April 1998

Media Contacts: Sarah Goodwin, 404/727-3366 -
Kathi Ovnic, 404/727-9371 -

(NOTE: Information on specific abstracts is embargoed for release until after each respective presentation; see below)

ATLANTA -- Since Spencer B. King III, M.D., implanted the nation's first coronary stent at Emory University in 1987, the design and appropriateness of stents to prop open damaged coronary arteries has continued to be researched and refined at Emory and other centers. Results of current stent research recently were presented at the American College of Cardiology (ACC) Scientific Sessions. Dr. King, who is among the presenters, was inducted as the first interventional cardiologist named president of ACC.

Efforts to reduce the risk of dangerous blood clotting that has plagued stent use since its inception are particularly relevant, says Nicolas A.F. Chronos, M.D., director of research for Emory's Gruentzig Cardiovascular Research Center, considering the enormous popularity of coronary stents as an adjunct to balloon angioplasty have gained since the promising results of studies with balloon-expandable stents became available in the United States around 1994. Since then, up to 80 percent of angioplasty procedures at some institutions have come to involve stents, estimates coronary stent developer Ulrich Sigwart of London, in the September/October issue of Science & Medicine.

The following is a sampling of ongoing coronary stent research at Emory's Gruentzig Cardiovascular Research Center:


Presented 11 a.m., E.S.T., Wed., April 1, 1998

"Surface Heparinization Profoundly Decreases Acute Thrombosis on Crown and Mini-Crown Stents in the Baboon Arteriovenous Shunt Model" Nicolas A.F. Chronos (Emory), Chris P. Markou (Emory), John Kocsis ( Cordis Corp.), Gerard Llanos (Cordis Corp.), Stephen R. Hanson (Emory). Session 1163; Poster No. 77 - Presentation: 9-11 a.m., April 1, West Exhibit Hall, GWCC

Heparin (a blood thinner) coating "abolished platelet thrombus (clot) formation for stents of all diameter, and under all flow conditions," reports Dr. Chronos and his colleagues in Abstract No. 77. "Thus, stent heparinization may profoundly inhibit thrombosis in the thrombogenic milieu associated with smaller vessels and acute coronary syndromes." The researchers integrated Crown and Mini-Crown stents covered in heparin-containing Carmeda BioActive Surface (CBAS) into arteriovenous shunts of baboons "under conditions which simulated stent applications in both small and medium-sized arteries... Thrombosis (clot, or emboli, development) complicates the use of metallic stents, yet stents are increasingly deployed in smaller vessels and in high-risk patients," the authors said.


Presented 4 p.m., E.S.T., Mon., March 30, 1998

"Tranilast Inhibits Neointima Formation in Balloon-Injured and Stented Pig Coronary Arteries, and Decreases Negative Remodeling after Balloon Injury" Sugao Ishiwata, Nicolas A.F. Chronos, George Lin, J. Jeffrey Marshall, Spencer B. King III, Keith Robinson (Division of Cardiology, Department of Medicine, Emory University School of Medicine)

Session 1063; Poster No. 103 - Presentation: 3-4 p.m., March 30, West Exhibit Hall, GWCC

"Tranilast (an anti-allergic, anti-keloid compound) is effective to inhibit neointima formation and adventitial remodeling in the pig coronary model of balloon restenosis, and inhibits neointima in stents; it may be useful clinically," reports Nicolas Chronos, M.D., and his colleagues in Abstract No. 103. "Studies to further define the mechanism are underway." The Emory team sought to replicate the findings of the recent TREAT multicenter Japanese clinical trial that showed an overall restenosis rate of 15 percent, about half the expected rate. "Tranilast significantly decreased neointima size normalized to the extent of injury and increased lumen size relative to overall vessel size in balloon-injured vessels; adventitia size as an index or remodeling, was decreased," the authors report.


Presented 10 a.m., E.S.T., Wed., April 1, 1998

"Clinical Outcome of Diabetic Patients after Palmaz-Schatz Stent Implantation"

Richard Blankenbaker, Ziyad Ghazzal, William S. Weintraub, Yannan Shen, Spencer B. King III (Division of Cardiology, Department of Medicine, Emory University School of Medicine)

Session 1163; Poster No. 88 - Presentation: 9-10 a.m., April 1, West Exhibit Hall, GWCC

"Despite similar procedural success rates and in-hospital complications, diabetics had a significantly higher mortality after stent implantation than the control group at follow-up," report Emory authors in Abstract No. 77, who evaluated survival rates for up to two years of patients who received the Palmaz-Schatz stent. The patients were comparable in all respects, except some had diabetes and some did not. Up to two years after stent implantation, 2.2 percent of diabetic patients had died compared with 0.5 percent of nondiabetic subjects (p = 0.064). The implications of this finding, according to the authors, parallels previous findings that diabetics have worse outcomes with balloon angioplasty alone. With a tendency toward high blood pressure, a higher incidence of congestive heart failure and a host of other cardiac and noncardiac complications, it would make sense that the arteries of patients with both diabetes and coronary artery disease would not adapt as well to stents, the authors say.


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