Discussion on the explosive growth and the potential risks of drug-eluting stents

Aug 9 2007

The Summer 2007 issue of The American Heart Hospital Journal explores one of the pivotal issues in cardiology, the drug-eluting stent (DES).

Through commentaries from ten leading national and international specialists, the issue presents a comprehensive discussion on the explosive growth and the potential risks of DESs.

The issue reports on the initial enthusiasm for drug-eluting stents, the great advances made possible by their use, and explores the significance of the benefits and disadvantages revealed through their high-volume adoption.

Dr. Ulrich Sigwart of University Hospital in Geneva, Switzerland, author of one of the studies, examines the sobering current appraisal of DES use, in contrast to the triumphs of their early success. "Subacute stent thrombosis due to incomplete intimal coverage, the formation of blood clots that can occur when the inner layers of blood vessels are not fully treated, remains the Achilles heel of DES use," says Dr. Sigwart. "The polymer matrix used for the delivery of drugs, which clearly induces inflammatory responses, may, in part, be responsible for very late thrombosis."

Dr. Renu Virmani and colleagues at the CVPath Institute of Gaithersburg, Maryland base the judgments in their article on the evidence obtained through pathologic studies of patients dying after stent implantation. "These data indicate that DESs cause both substantial impairment in arterial healing characterized by lack of complete re-endothlialization (the re-healing of the inner surfaces of vessels after stenting) and persistence of fibrin, a protein that indicates blood clotting, when compared with bare metal stents. This delayed healing is the primary substrate underlying all cases of late DES thrombosis at autopsy."

In contrast, Drs. Williams and Abbott, of Brown Medical School and affiliated with Rhode Island Hospital, note, "DESs are a revolutionary advancement in interventional cardiology and are here to stay. Recognizing that they are different from bare metal stents, it is prudent to exercise caution with these devices and avoid using them in patients in whom dual antiplatelet therapy, a common practice used to reduce blood clotting, is unlikely or impossible."

Dr. Peter Fitzgerald of Stanford University Medical Center, who writes with his colleagues, Drs. Shimohama and Honda of the Center for Cardiovascular Technology, offers his view of the future of DESs. "While first generation DESs place great emphasis on efficacy, long-term safety issues have arisen, making DESs stand in an exquisite balance among occasionally conflicting effects. Careful reexamination of research findings, as well as redefinition of safe and effective outcomes, will lead future stent technology in the optimal direction."

http://www.blackwellpublishing.com