Medical Device Daily Associate Managing Editor

Have drug-eluting stent (DES) devices been over-hyped?

The benefits of switching from bare-metal stents to costlier DES systems to open/reopen blocked coronary arteries may be smaller than previous trials indicated, according to a study published in the August issue of Clinical Cardiology.

The findings, based on data provided by Goodroe Healthcare Solutions (Norcross, Georgia), are notable, particularly given ongoing discussions about the safety and effectiveness of DES, including indications from researchers last week at the European Society of Cardiology (ESC; Sophia Antipolis, France)annual meeting in Barcelona, Spain, indicating that DES devices may increase the risk of potentially fatal blood clots in the form of late thrombosis (Medical Device Daily, Sept. 6, 2006) and at the EuroPCR meeting this past May in Paris (MDD, May 17, 2006).

Bare-metal stents often require repeat treatment known as revascularization following reclogging, or restenosis, of the artery. DES devices, newer and more expensive, have been touted as reducing restenosis via the elution of a drug coating.

For their study, the researchers — interventional cardiology expert Spencer King, III, MD, from the Fuqua Heart Center of Piedmont Hospital (Atlanta); Cynthia Yock from the Center for Primary Care and Outcomes Research at the School of Medicine at Stanford University (Palo Alto, California); and Mike Isbill of Goodroe — reviewed outcomes from 17,000 bare-metal stent patients and found that less than 8% of the patients needed additional blockage treatment after the first follow-up month. This is less than half the rate originally reported in most DES trials.

Goodroe, focused on helping hospitals improve clinical quality and economic performance, looked at detailed clinical data from 17,000 people who received bare-metal stents from December 1998 through March 2003. The information was collected from 17 hospitals across the country that use Goodroe's CathSource Enterprise software, which feeds information into the Goodroe Data Warehouse, that the company says is one of the nation's largest warehouses of data on outcomes, costs and productivity measures for cardiac catheterization labs, as well as for cardiac and orthopedic surgery procedures.

“This study provides a real-life example of the importance of collecting and evaluating clinical data,” said Joane Goodroe, founder of Goodroe Health. “Now, we have information that questions the value of using expensive drug-eluting stents, rather than bare-metal stents, during cardiac catheterization procedures.”

The study, she noted, adds to a growing body of evidence that bare-metal stents are effective, and may in fact be more effective than earlier trials had suggested. “This effort demonstrates that hospitals must have access to better outcomes data to make smarter decisions about the resources they use to provide patient care,” Goodroe added.

Goodroe said that physicians' rapid acceptance of DES in 2002 was based on evidence from manufacturer-sponsored clinical trials that showed they reduced the need for revascularization by as much as 81% compared with bare-metal stents. However, the Stanford study, along with meta-analysis, which were published in The Lancet, shows there is no significant difference in serious events, such as mortality and post-stent heart attack, between patients receiving DES and those receiving bare-metal stents.

“Our most recent study indicates that while drug-eluting stents may be the latest technology for coronary disease, they do not provide the degree of improvement in clinical results that was suggested by the trials,” said King, former president of the American College of Cardiology (Bethesda, Maryland) and a pioneer in the development of the angioplasty procedure.

Because coronary disease is progressive in nature, many patients require additional catheterization procedures to clear blockages in other areas. However, the Stanford study by King et al. found that in 19 out of 20 subgroups of the bare-metal stent patients, 4% to 10% of the patients required repeat revascularization. With 90% of all stent patients now receiving DES devices to prevent further blockages, this study suggests that many of patients would be equally well served by using bare-metal stents.

It is starting to appear that the DES concerns voiced at the ESC meeting were not unfounded, as one of the primary makers of the devices, Boston Scientific (Natick, Massachusetts) disclosed to the Wall Street Journal last week that its hugely popular Taxus DES increases the risk of blood clots.

Paul Donovan, a spokesman for the company, emphasized that though the company has found some evidence for clots, the drug-coated stents do not significantly increase the risk of heart attack or death.

Boston Scientific said it has raised the issue with the FDA, which does not comment on discussions with regulated companies.

More than 6 million people worldwide have already been implanted with a DES device.