Combining Heart and Stroke-Prevention Surgeries Raises Death Risk
Researchers say more investigation is needed into linking the procedures
MONDAY, Jan. 15, 2007 (HealthDay News) -- Combining heart-bypass surgery with surgery to prevent stroke increases the risk that a patient will die or suffer a post-operative stroke, a new study has found.
"This means that the benefit of combining the two-in-one operation or one hospital stay hasn't been proven," said study lead author Dr. Richard M. Dubinsky, associate professor of neurology at the University of Kansas Medical Center in Kansas City. "This is something that would be worthy of a randomized controlled trial."
Heart-bypass surgery reroutes blood flow around clogged arteries, while carotid endarterectomy, the most commonly used stroke-prevention surgery, removes plaque in the carotid arteries, which supply blood to the brain, the study authors said.
The idea behind combining the procedures is to protect the carotid artery from becoming blocked during the heart-bypass surgery and to reduce the overall risk by having just one surgery. But while the frequency of combined surgery has increased, evidence of any real benefit is unclear.
According to the American Academy of Neurology, about 700,000 people have a stroke each year. Some 80 percent of these are due to a blood vessel being blocked.
For this study, published in the Jan. 16 issue of Neurology, the researchers reviewed hospital discharge data on almost 658,000 patients from the Nationwide Inpatient Sample, all of whom were admitted to U.S. hospitals for carotid endarterectomy or coronary bypass artery surgery from 1993 to 2002.
Because of limitations of the database, some of the patients may have had the procedures a few days apart, while others had both at the same time. For the purposes of this study, however, all were grouped together.
Patients who combined the two procedures had a 38 percent greater chance of death or postoperative stroke than patients who underwent coronary artery bypass surgery alone, the study found.
However, one problem with the study is that the authors weren't able to compensate for disease severity. "The excess of mortality may just be that they're sicker," Dubinsky said.
Women had a lower risk of postoperative death or stroke than men, the researchers noted. This is the first study to show this, the team said.
A second study in the same issue of Neurology found that fewer elderly people are undergoing carotid endarterectomy for the wrong reasons. This apparently is the result of publication of randomized controlled trials that concluded that about one-third of these surgeries were unnecessary.
"Fewer patients are undergoing stroke prevention surgery for the wrong reasons and this can be viewed as a success of evidence-based medicine and public investment in rigorous evaluation of surgical procedures," said Dr. Ethan Halm, lead author of the study and associate professor of medicine and health policy at the Mount Sinai School of Medicine in New York City.
Only 8.6 percent of procedures were deemed unnecessary, the study found. That's still a large number, however -- 11,500 in the United States annually, the study concluded.
Still, more patients without symptoms are undergoing the operation. "That's a concern because asymptomatic patients have less to gain from the surgery," Halm said.
The American Heart Association has more on carotid endarterectomy.