TUESDAY, June 14, 2005 (HealthDay News) -- People who came to a hospital many hours after suffering a heart attack did better with invasive artery-opening treatment that included the implant of a stent than with clot-dissolving drug therapy.
That's the conclusion of a new German study that might one day challenge current treatment guidelines.
The amount of heart tissue destroyed by the heart attack was smaller in patients who got the invasive treatment, and they were also less likely to die, have a second heart attack or suffer a stroke than those given noninvasive clot-dissolving treatment, the researchers found.
"This finding increases the level of evidence in support of the invasive strategy and deserves consideration when current treatment guidelines for this category of patients will be reassessed," the report concluded.
Current guidelines are based on previous studies that found that reopening arteries more than 12 hours after a heart attack is not effective because of damage already done to the blood vessel by a complete stoppage of blood flow.
But many of the 365 patients in the German trial, all of whom were treated 12 to 48 hours after the heart attack began, did not suffer a total stoppage of blood flow, pointed out Dr. Sidney C. Smith Jr., a spokesman for the American Heart Association and a professor of medicine at the University of North Carolina.
"In this group, 50 percent of the patients had some blood flow in the blocked artery," Smith said. "In the group that had a totally blocked artery, half of them had blood flow coming in from collateral vessels."
The study, by cardiologists at Technische University in Munich, appears in the June 15 issue of the Journal of the American Medical Association.
An accompanying editorial by Drs. Raymond J. Gibbons and Cindy L. Grines, cardiologists at the Mayo Clinic, in Rochester, Minn., and William Beaumont Hospital, in Detroit, respectively, questioned whether current treatment guidelines should be changed. Those guidelines place artery-opening procedures as a second choice.
Their answer: "Probably not yet."
The German trial results "are a noteworthy challenge to existing dogma and an important contribution to current knowledge," the physicians wrote. "However, the results do not yet justify a revolution in clinical practice."
Other studies now under way may decide whether such a revolution is justified, Smith said. At least one major study is trying to determine whether invasive artery-opening treatment is justified when patients show up many hours after a heart attack, he said.
But the real message of the German study is the need for earlier detection and treatment of heart attacks, Smith said. Studies have shown that up to 40 percent of people who have a heart attack do not go for treatment quickly because they do not recognize the symptoms, he noted.
"If we really want to increase the benefits of treatment, early symptom recognition and early opening of the artery still holds the greatest promise," Smith said.
More information
A guide to the sometimes-subtle symptoms of a heart attack is offered by the American Heart Association.
