Medical Device Daily Senior
Limiting the use of drug-eluting stents to a selected group of patients is cost efficient and did not increase risk of death or heart attack within a year, according to a new analysis published in Circulation: Journal of the American Heart Association.
The researchers said the selective use of drug-eluting stents, which began in 2007, is saving the U.S. healthcare system about $400 million a year.
Stents are metal scaffolds inserted into an artery after angioplasty to prop it open. Drug-eluting stents are coated with medicine to help prevent blood clots. Compared to bare-metal stents, drug-eluting stents can reduce recurrent artery narrowing, research shows.
In this analysis, researchers compared the use of drug-eluting stents in 2004 through 2006 to their use in 2007, using data from the Evaluation of Drug-Eluting Stents and Ischemic Events registry. This U.S.-based registry of percutaneous coronary interventions — also known as PCI or angioplasty — included 10,144 patients undergoing angioplasty at 55 medical centers.
The use of drug-eluting stents decreased from 92% in 2004 through 2006 to 68% in 2007. At the same time, rates of death and heart attack remained virtually unchanged, while procedures to re-treat a blockage at the same coronary artery site increased slightly, from 4. 1% to 5. 1%.
“The bottom-line was that using drug-eluting stents in a relatively unselected way was only resulting in marginal improvement compared to more selective use,“ said David Cohen, MD, senior author and director of cardiovascular research at Saint Luke's Mid America Heart and Vascular Institute (Kansas City, Missouri).
In the earlier years of broader use, “we were putting a lot more drug-eluting stents in and we benefited very few additional patients,“ he said.
Several studies in late 2006 reported a higher risk of clotting, heart attacks and deaths in patients with drug-eluting stents compared to bare-metal stents. That year, at the World Congress of Cardiology (WCC; Sophia, Antipolis, France) annual meeting in Barcelona, Spain, researchers issued reports indicating that drug-eluting stent (DES) devices may increase the risk of potentially fatal blood clots (Medical Device Daily, Sept. 6, 2006).
At that time, nearly 6 million patients worldwide had received a DES since the devices were first launched in 2002, creating a $5-billion-a-year business for then market leaders Boston Scientific (Natick, Massachusetts) and Johnson & Johnson (J&J; New Brunswick, New Jersey), the only two companies at that time that sold the devices in the U.S.
At that meeting, Salim Yusuf, MD, of McMaster University (Hamilton, Ontario), called the findings disconcerting. “Now that we are having this concern, I would urge limited use,“ he said. “As clinicians we seem to have lost our clinical judgment, let alone our ability to view data and evidence. We therefore need a thoughtful and selective approach to PCI, complementing full medical therapy . . . The whole field of angioplasty has been led astray by a preoccupation with restenosis, for which study after study has shown has no prognostic value.“
Soon after that WCC meeting, an editorial published on the web site of the American College of Cardiology (ACC; Washington) added fuel to that fire, charging that 2,000 patients were dying needlessly each year as a result of DES use.
Written by Sanjay Kaul, MD, and George Diamond, MD, of Cedars-Sinai Medical Center (Los Angeles), the guest editorial, “Drug-eluting stents: An Ounce of Prevention for a Pound of Flesh,“ said patients face a lower risk if treated with older, less costly, bare-metal stents (BMS) that might work, in many cases, just as well.
“I think the debate here is not the drug-eluting stent vs. the bare metal stent,“ Kaul told Medical Device Daily in 2006. “There's a bigger debate here, and that is our obsession with revascularization as the primary therapy for treating stable angina.“
He said that drug therapy should be the first avenue for treating chronic stable angina “and only in those who don't respond to [drug] therapy should revascularization therapy — whether stenting, angioplasty or bypass surgery — be offered.“ He said that in a “quick fix society,“ patients demand that approach, and “we are too eager to please them.“
With more than one million Americans annually receiving the stents at that time, and at least 80% of them getting DES devices, this works out to an additional 2,160 deaths each year, the doctors calculated. The figure assumed that 45% of the people who suffered such clots had died.
Kaul also said during that time that DES is the proper application for many patients, but that the devices were used far too often in cases where clinical data suggested that BMS use or long-term drug therapy was safer. Only about 20% of DES devices were being inserted in patients who have the kinds of conditions studied in the clinical trials that led federal regulators to approve them, he said.
The 2006 studies led to the FDA examining the issue later that year (MDD, Dec. 11-12, 2006).
“These concerns led to a stair-step reduction in the use of drug-eluting stents, which had expanded rapidly since their introduction in 2003,“ said Cohen, also a professor of cardiovascular research at the University of Missouri-Kansas City. “Because of the safety concerns, we were able to verify what many of us had suspected — that using drug-eluting stents in virtually all patients is not that efficient.“
While Cohen believes the FDA concern was appropriate at the time, newer evidence with longer follow-up and more data has indicated that drug-eluting stents are safe. “Our current understanding is there is no real excess risk,“ he said. Later risk of dangerous clots might be balanced by earlier benefits.
Researchers found that when use of drug-eluting stents declined in 2007, the stents were more likely to be placed in patients who were at highest risk of re-blockage — including younger patients with smaller vessels or with longer problem areas in the vessels being treated. “Because we were selectively targeting the highest-risk patients, we were able to use far fewer drug-eluting stents while preserving the clinical benefit,“ Cohen said.
Researchers estimated that when compared with less selective use of drug-eluting stents in 2004-2006, more selective use in 2007 reduced healthcare costs by an average of $401 per patient. Per-patient cost is magnified into hundreds of millions of dollars each year, given the nearly one million angioplasty procedures performed in the U.S., the authors noted.
Policy makers should appreciate that more targeted use of drug-eluting stents produces comparable clinical outcomes at a lower cost, Cohen said. “There are ways that we can enhance this treatment pattern through healthcare policies, professional guidelines or appropriate use criteria.“
The new analysis doesn't directly identify which patients are the best candidates for drug-eluting stents, although other studies are currently underway using similar patient registries to answer these related questions. The analysis was also limited to one year, although restenosis usually occurs within that timeframe.