Drug-Coated Stents as Good as Bypass Surgery
Study finds complication, survival rates essentially same
THURSDAY, April 19, 2007 (HealthDay News) -- Drug-eluting stents had roughly the same risk and the same outcomes as bypass surgery for patients with coronary artery disease, researchers report.
"What it means is if you find yourself in a situation where a bypass surgery is refused and the patient elects to have percutaneous treatment rather than bypass, we can do it," said senior study author Dr. James Wilson, program director of the cardiology fellowship program at St. Luke's Episcopal Hospital/Texas Heart Institute in Houston. "We're not causing harm by doing it."
The patients in the study tended to be sicker, Wilson said, but that suggests that if drug-eluting stents were used in lower-risk patients, outcomes might be even better.
The findings, presented Thursday at the American Heart Association's annual conference on Arteriosclerosis, Thrombosis and Vascular Biology in Chicago, are part of a larger scientific effort to figure out which technologies are the best fit for individual patients.
In other words, one size does not fit all.
Individuals whose coronary arteries have been narrowed by atherosclerosis ("hardening of the arteries") can usually go one of two routes: bypass surgery to reroute the blood flow or the implantation of a stent, a tiny mesh tube placed into the arteries after angioplasty to prop them open and increase blood flow.
There are now two types of stents: conventional bare metal stents and, more recently, drug-eluting stents. The latter are coated with a medication intended to prevent re-blocking of the vessel, a common problem with bare metal stents.
Previous research showed that bare metal stents were safer than bypass surgery, although bypass had more long-term success because of a lower risk of vessels closing back up.
"We have, in the past, compared patients who got bare metal stents to bypass surgery and, and early on, [stents] looked pretty favorable because the procedure caused less problems," Wilson said. "It seemed like a safer procedure but, in the long term, bypass gave better protection."
There is little research comparing the newer drug-eluting stents with bypass surgery, however. Wilson and his colleagues hypothesized that drug-eluting stents might have an edge over bypass because they supposedly lower the chance of renarrowing.
In this study, the investigators analyzed 799 patients with drug-eluting stents and an equivalent number of patients who had undergone coronary bypass surgery. The trial was funded by Cordis Johnson & Johnson, which makes drug-eluting stents.
The risk of any complication happening in the hospital was found to be statistically equivalent between the two groups: 5.01 percent for those undergoing bypass and 3.78 percent for those getting drug-eluting stents.
The risk of heart attack was also similar in both groups, although patients undergoing bypass surgery had a higher risk of stroke (1.11 percent vs. 0.11 percent).
Three-year survival rates were essentially the same, at 6.6 percent in the bypass group and 9 percent in the stent groups.
"Our reaction was one of surprise," said study author Dr. Muhammad S. Munir, a nonclinical research fellow at the Texas Heart Institute. "This was, to me, indicative of the fact that if we have healthier, less sick patients, then drug-eluting stents would perform much better. My conclusion is that if the patients are selected in a careful manner, then drug-eluting stents would be safe and beneficial."
"What's happened is we've tried to tackle sicker patients and more difficult lesions, and we gave up the early edge we had," Wilson said.
The issue of patient selection is a critical one, agreed Dr. Stephen Lahey, director of cardiothoracic surgery at Maimonides Medical Center in New York City. But he wasn't sure this study answered the question.
"There are people it is absolutely appropriate they should get drug-eluting stents and some it's absolutely appropriate they should get surgery," Lahey said. "In the future, I think it's going to be a combination of both. I think the newer way to approach some of these patients would be a less invasive surgical approach to one artery and deployment of a drug-eluting stent in another artery. This particular paper did not really get down to that."
For more information on heart bypass surgery and stents, visit the American Heart Association.