Drug-Coated Stents: The Real Risks
Use for Complex Heart Disease May Be Riskier Than Once Thought
May 8, 2007 - For about half of patients who've been getting them,
drug-coated stents are more risky than previously thought.
Drug-coated stents don't clog up as easily as bare-metal stents. They've
been tested -- and approved -- only in patients with relatively mild coronary
heart disease. But doctors have been using these devices "off label" in
far more complex cases.
What kind of risk does this off-label use mean for patients? Two new studies
look at the issue. Both show that "off-label" or "untested" use
of the drug-coated stent approximately doubled a patient's short-term risk of
death, heart attack, dangerous blood clot, or reclogging of the artery.
Neal S. Kleiman, MD, director of the cardiac catheterization lab at
Houston's Methodist DeBakey Heart Center, led a study of 3,323 patients at 42
different U.S. hospitals who got at least one drug-coated stent.
While still in the hospital, the off-label patients had a small (0.4%) but
higher risk of developing a dangerous blood clot in their stents. A year after
getting their stents, the off-label patients still had more than twice the risk
of death, heart attack, or reclogging (17.5%) as the on-label patients
"We knew before that patients who fell into these off-label categories
were at higher risk -- we just didn't know how much higher," Kleiman tells
WebMD. "Now we know their risk is 2.25 to 2.5 times higher. And we know
what patient characteristics confer the risk."
Charles J. Davidson, MD, director of the cardiac catheterization lab at
Northwestern Memorial Hospital in Chicago, and colleagues studied 5,541
patients who got drug-coated stents at 140 U.S. hospitals.
They found a greater than twofold higher risk of death, heart attack, and
stent clotting in the patients with off-label stents. But after adjusting for
disease severity, the safety of drug-coated stents was similar in both the on-
and off-label groups.
"We found that compared to standard [on-label] use, there was about a
half a percent higher risk of death or heart attack when patients got
[drug-coated] stents off label," Davidson tells WebMD. "At first glance
one would be concerned this was about twice that of the standard group, but at
second look, less than 1% of the off-label patients had any adverse event. The
difference was related to the patient factors. The device performed just as
well off-label as it did in standard indications."
Both studies appear in the May 9 issue of The Journal of the American
Putting Stent Risk Into Perspective
What does all this mean to the patient who is considering getting a
Robert A. Harrington, MD, professor of medicine at Duke University and
director of the Duke Clinical Research Institute, is an interventional
cardiologist who has studied the stent issue.