TUESDAY, Nov. 14, 2006 (HealthDay News) -- Opening a patient's arteries with angioplasty plus a stent three to 28 days after a heart attack does not cut the risk of having another heart attack, going into heart failure or dying, new research shows.
"These particular patients do not benefit from angioplasty," said study author Dr. Judith Hochman, clinical chief of cardiology at New York University School of Medicine in New York City.
"Early treatment with angioplasty or blood clot-dissolving drugs in the early hours of a heart attack is proven care," Hochman stressed. "It saves lives. It saves heart muscle. This study doesn't bear on that. The standard accepted time window for all comers is 12 hours but if a patient is unstable or has recurrent chest pain, then we would do angioplasty even after the 12 hours." The patients in Hochman's study were considered stable.
The findings are being published early online in the New England Journal of Medicine to coincide with a presentation Tuesday at the annual meeting of the American Heart Association, in Chicago.
The trial is considered a "negative" study because it failed to show a benefit.
"Negative studies contribute to our understanding of what is really important," Dr. Ray Gibbons, president of the American Heart Association, said at a Sunday news briefing. "This is a good example of a negative study that will improve the efficiency of health care in this country. The U.S. health-care system is remarkably inefficient."
Right now, standard practice is to open arteries that are 100 percent blocked in the first 12 hours after a heart attack. But according to an accompanying editorial in the journal, the practice has been widely adopted even after that time window closes, despite the absence of good evidence to support it.
The current study sought to define the window of opportunity more specifically.
"We hypothesized that patients with a totally blocked artery would benefit from opening it in addition to using proven medications [after the initial 12 hours]," Hochman stated.
The 2,166 stable patients in this study had 100 percent blockage of the heart attack-related artery three to 28 days after the initial heart attack. Because of this, they were considered at high risk for further cardiovascular events.
"I want to be extremely clear," Hochman said during a Tuesday news conference. "We're only drawing conclusions related to the population that we enrolled."
Participants were randomized to receive either angioplasty (percutaneous coronary intervention or PCI) and stenting with drug therapy or drug therapy alone.
The results turned out to be the opposite of what the researchers expected.
During an average three years' follow-up, they found no statistically significant difference between the two groups in rates of repeat heart attacks, heart failure or death. In fact, the group that received angioplasty showed a troubling trend toward repeat heart attacks, although it was not clear if this was due to chance.
"We expected that the chance of death, development of severe heart failure or another heart attack would be reduced 25 percent by adding angioplasty to optimal medical therapy. We didn't find that," Hochman said. "It turns out that both groups were on excellent medical therapy, so we now emphasize secondary prevention such as stopping smoking, losing weight and controlling diabetes and high blood pressure."
It's not clear why the findings turned out the way they did, although it's possible that opening a blocked artery may interfere with the ability of smaller vessels to make up the deficit.
For more on heart attacks, visit the American Heart Association.