Danger is greatest in first six weeks, study finds
WEDNESDAY, May 5 (HealthDay News) -- People who've had a stent implanted to keep a coronary artery open face an increased risk for heart complications and death if they have non-cardiac surgery in subsequent weeks, a new Scottish study has found.
"We looked at the risks connected to four and six weeks after surgery," said study author Nicholas L.M. Cruden, a former cardiology lecturer at the University of Edinburgh and now a consultant for the National Health Service in Scotland. "Most of the risk was in the first six weeks. Between six weeks and one year, the risk was somewhat reduced, but still higher than expected."
The study, published online May 4 in Circulation: Cardiovascular Interventions, found that 42 percent of people undergoing non-cardiac surgery within six weeks of stent implantation were more likely to have such complications as decreased blood flow to the heart and heart attacks or to die. These outcomes were found in just 13 percent of those whose surgery was done more than six weeks after stent implantation.
The risk of heart problems after non-cardiac surgery was even greater for the 65 percent of people whose stents were inserted because of a recent heart attack, compared with those had stable but chronic heart disease when they were given stents, the study found.
There are no formal British guidelines about surgery after stent implantation, Cruden said, but in France, he said, guidelines recommend that such surgery be postponed at least for a year.
Guidelines issued by the American Heart Association and other organizations in the United States recommend delaying surgery for at least a year after a stent implant, said Dr. Charles W. Hogue Jr., associate professor of anesthesiology at Johns Hopkins University School of Medicine.
The pros and cons of using clot-preventing drugs such as Plavix after stent implants have been debated for years, Hogue said. "The guidelines set antiplatelet therapy for a year or maybe indefinitely," he said. "If you stop, you run the risk of stenosis [artery blockage]. But what happens if you have a tendency to bleed? That can cause all kinds of problems, particularly for the brain or the eye."
Use of clot-preventing medication has to be decided patient by patient, Hogue said. "You have to judge risk vs. benefit on an individual basis," he said. "This is a big public health issue because a lot of stents are being implanted."
About 1.3 million artery-opening procedures are performed annually in the United States, Hogue said.
The Scottish study is the largest done to date on the effects of surgery after stent implants, Cruden said. The study shows a 50 percent increase in the risk for bleeding in such cases but no impact on surgical mortality, he said.
The American Heart Association has more on stents.
SOURCES: Nicholas L. M. Cruden, Ph.D., consultant, National Health Service, Glasgow, Scotland; Charles W. Hogue Jr., M.D., associate professor, anesthesiology, Johns Hopkins University School of Medicine, Baltimore; May 4, 2010, Circulation: Cardiovascular Interventions, online
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