Fewer deaths, heart attacks found in 18-month study
WEDNESDAY, Jan. 23 (HealthDay News) -- Bypass surgery provides a lower risk of death and heart attacks than stents for people with blockages of at least two heart arteries, a large-scale study indicates.
The finding is far from the last word on the stent-versus-surgery debate in such cases, said study author Dr. Edward L. Hannan, associate dean for research at the State University of New York at Albany School of Public Health. "But there isn't any other study right now that is better than this," he added.
"Physicians need to inform patients about these results and need to engage in a dialogue that includes these findings to determine what is the proper treatment for multi-vessel disease," Hannan said.
Hannan and his colleagues studied the outcomes of more than 17,400 procedures for people with multiple blocked coronary arteries. The outcomes were consistently better in an 18-month follow-up for bypass surgery than for the artery-opening procedure called angioplasty followed by insertion of a drug-coated tube known as a stent.
For example, 92.1 percent of those who had surgery for three blocked arteries had no heart attacks and were alive, compared to 89.7 percent of those who got stents. For those with two blocked arteries, the comparable numbers were 94.5 percent for surgery and 92.5 for stent implants.
The study was not the kind of randomized, controlled trial regarded as the gold standard for medical research. It was observational, meaning that the researchers simply recorded what happened in medical practice rather than trying to control all the factors involved in choosing a treatment.
"But the randomized trials done in the past have not necessarily been better," Hannan said. "They were restricted to patients who were not very sick, and they also did not recognize that when you compare two treatments, some patients might not prefer the one that is more invasive."
Surgery is more invasive than angioplasty, since it requires the chest to be cut open. Angioplasty is done by threading a flexible wire called a catheter through a blood vessel into the heart.
One shortcoming of the study is the relatively short follow-up period of 18 months, said Dr. Joseph P. Carrozza, an associate professor of medicine at Harvard Medical School, who wrote an accompanying editorial. "One would like to see patients followed for up to five years," said Carrozza, who is an interventional cardiologist at Beth Israel Deaconess Medical Center.
"There is nothing in this study that makes us feel surgery is the treatment of choice for patients with multi-vessel disease," he added. Such a verdict will have to wait on the results of several randomized trials now underway, Carrozza said. "This is just one piece of evidence we have right now before we get the final word," he noted.
And yet, Carrozza conceded, "this is the first really large study to look at this issue now" and thus should be considered by doctors and heart patients requiring treatment for blocked coronary arteries.
Another report in the same issue of the journal compared the safety of bare-metal to drug-coated stents for so-called "off-label" uses -- implants for conditions where there is no formal government approval. About half of all stent implants are for such conditions.
Questions have been raised about the safety of drug-coated stents in off-label conditions, said a report by a group led by Dr. Oscar C. Marroquin of the University of Pittsburgh. But the study of 6,551 cases found a lower rate of complications and no increased risk of death or heart attack for drug-coated stents as compared to the bare-metal kind. "These findings support the use of drug-eluting stents for off-label indications," the researchers wrote.
That report comes on the heels of a study of off-label use of a different kind of stent, developed for use against bile duct obstructions in cancer patients. More than 1 million patients got stents for off-label conditions between 2003 and 2006, according to a report by Dr. William Maisel, director of the Medical Safety Device Institute at Beth Israel Deaconess. Some 1,000 malfunctions of the devices were reported, 81 percent of them in off-label uses.
You can learn more about why and how stents are used from the American Heart Association.
SOURCES: Edward L. Hannan, M.D., associate dean, research, State University of New York at Albany School of Public Health; Joseph P. Carrozza, M.D., associate professor, medicine, Harvard Medical School, Boston; Jan. 24, 2008, New England Journal of Medicine
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