May 30, 2007 -- As concern and investigation continue concerning the link between drug-eluting stents and late-stent thrombosis, focus is now turning to the issue of improperly implanted stents by physicians. "The Wall Street Journal" reports this week that cardiologists' overconfidence in the benefits of drug-coated stents may have contributed to sloppy technique.
A recent study sponsored by a stent maker, states the Journal, found that two-thirds of the stents were implanted incorrectly.
In response, the Cardiovascular Research Foundation, a prominent advocate of stent technology, is launching an 11,000-patient study that is designed in part to examine whether less-than-optimal deployment of a stent is linked to the type of clots at the center of the debate, those that occur more than a year after implantation.
"We went through a period with drug-eluting stents thinking that it might not be so important to put them in perfectly," says Kirk Garratt, cardiologist at Lenox Hill Hospital, New York. "There was so much optimism and confidence about the stents that people might have gotten a little lazy," he says. Dr. Garratt and the other cardiologists quoted in this article consult for or get research-grant support or speaking fees from companies that make products used in stent procedures; in some cases, grants or fees are paid to the institution and not directly to the doctor.
The clotting problem, known as very late thrombosis, is rare, occurring in probably less than 0.5 percent of the roughly one million stent procedures done in the U.S. each year. But it happens long after doctors have believed patients were out of such danger, and the result is often either death or a major heart attack. The chief remedy is to keep patients for at least a year on both aspirin and a second drug called Plavix to prevent clots. But cost and bleeding risks are among the drawbacks to that strategy.
The Journal adds that not all experts agree that physician technique is a big culprit, and that most believe very late thrombosis has multiple contributors. Gary Mintz, a cardiologist at Cardiovascular Research Foundation, says that over time, the body's healing process covers over the stent, as well as placement shortcomings. "The effect of poor technique diminishes as time gets longer from implantation," he says.