Interventional cardiology is feeling its way toward a new consensus on when to use drug-eluting coronary stents, or coronary stents of any type, be they drug eluting or bare metal.
Fueled by concern about an increased risk of thrombosis in patients who receive drug-eluting stents (DES), compared with the bare-metal variety, cardiologists agree that DES should not be placed in patients who are not sure to stay on dual antiplatelet therapy with aspirin and clopidogrel (Plavix) without interruption for at least 1 year.
Adding to the flux was a landmark report last March at the annual meeting of the American College of Cardiology on the safety of deferring coronary stenting in selected patients with stable coronary disease. Results from the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial (N. Engl. J. Med. 2007;356:1503–16) may have contributed to a small drop in stent use overall.
Other shifts in use of DES have also been occurring but are harder to pin down. Off-label use of DES in complicated patients has drawn increased scrutiny in recent months because their risk of thrombosis is higher than the risk in patients for whom DES have labeled approval. But cardiologists are quick to add that complicated patients are the ones who stand to gain the most from the reduced incidence of restenosis with DES.
Aside from avoiding placement of DES when dual antiplatelet therapy can't be assured, “the only consensus is that everyone has become much more deeply thoughtful” about using them, said Dr. Mitchell W. Krucoff, a cardiologist and professor of medicine at Duke University, Durham, N.C. DES use is no longer the “runaway train” it was a couple of years ago, when virtually all coronary stents placed in U.S. patients were drug-eluting stents.
“I've been a little more thoughtful about which stent I use,” agreed Dr. Eric R. Bates, a cardiologist and professor of medicine at the University of Michigan, Ann Arbor. “In the past, I was just using DES in everybody.”
“It's a pullback from what was probably too much [DES use] to what's probably right,” said Dr. Deepak L. Bhatt, a cardiologist at the Cleveland Clinic.
The drop is documented in recent statistics on DES use.
This past June, DES were used for about 71% of all patients receiving a coronary stent, according to data collected in 75 representative hospitals throughout the United States by Goodroe Healthcare Solutions LLC. A year earlier, in July 2006, about 86% of all coronary stenting at the same hospitals used DES.
Expressed a different way, Goodroe found that last January about 72% of all coronary intervention procedures used a DES, about 22% used bare-metal stents (BMS), and about 6% involved balloon angioplasty only with no stent. Five months later, in June, DES use had dropped to 66% of all coronary procedures, with BMS use rising to 26% and balloon angioplasty up to 8%. (See box.)
DES manufacturers report a similar picture. In July, Johnson & Johnson, which markets the sirolimus-eluting coronary stent (Cypher), and Boston Scientific Corp., which sells the paclitaxel-eluting stent (Taxus), both reported that U.S. sales of these stents during April-June 2007 were down by about 40%, compared with the same quarter in 2006.
An informal survey of a handful of cardiologists showed the clinical side of the story. At Piedmont Hospital in Atlanta, the use of DES has shifted from “close to 90%” of patients receiving coronary stents a few years ago to “about 70%–75%,” said Dr. Spencer B. King III, chairman of interventional cardiology at the hospital. At Duke, DES use dropped from about 85% of all coronary stents a year or so ago to about 75%, Dr. Krucoff said in an interview. Dr. Bhatt estimated the change in use at the Cleveland Clinic to be about 10%–15% less than a year ago.
Which patients were receiving DES last year but are now getting BMS instead?
One clear answer: those who can't be relied on to take aspirin and clopidogrel for at least 1 year, the length of treatment that's now recommended to prevent stent thrombosis and the death or MI that could result from a clot forming in a stented artery. A patient's ability to stay on the regimen might be suspect because of a history of poor compliance; anticipated difficulty in affording expensive clopidogrel (about $4 a day); a history of bleeding problems, such as a chronic ulcer; an existing warfarin regimen because of atrial fibrillation; or pending surgery that might mean stopping one or both drugs for a few days. Patients undergoing stenting for an acute myocardial infarction also usually get BMS because their ability to stick with long-term antiplatelet therapy is uncertain as they receive emergency treatment.