MONDAY, Oct. 28, 2002 (HealthDayNews) -- The lifesaving effects of beta blocker drugs for many people who have heart attacks or major heart rhythm disturbances last a lot longer than has been thought, a study finds.
It's long been known that beta blockers, so called because they reduce the work of heart muscle by blocking activity of stress-related neurotransmitters such as epinephrine, lower the death rate in the hours and days after a heart attack. Now a report in tomorrow's issue of Circulation: Journal of the American Heart Association shows that lives are saved even years later, not only for heart attack patients but also for those whose heart rhythm is irregular enough to raise the risk of sudden, fatal cardiac arrest.
"What we have added is that they have ongoing benefits remote from an immediate myocardial infarction [heart attack]," says Dr. Kristin E. Ellison, assistant professor of medicine at Brown Medical School and lead author of the journal report. "The median time of enrollment in our study was 30-something months."
Over that period, heart attack patients who were given beta blockers consistently did better than those who weren't. The death rate for beta blocker patients was 16 percent lower after two years and 34 percent lower after five years, compared to patients who didn't get the drugs.
The finding won't cause any dramatic change in treatment, but it adds powerful reinforcement to current recommendations for use of beta blockers in a specific patient group, Ellison says. "Hopefully, everyone is prescribing beta blockers to this patient population," she says. "There are no harmful effects and clear benefits, so the drugs should not be withheld from this patient population."
All of the more than 2,000 patients in the study had suffered heart attacks that substantially reduced the heart's ability to pump blood. Some were also found to have abnormally fast, irregular heartbeats, or tachycardia, which can cause sudden death.
The primary purpose of the study was to see whether careful monitoring of the heart's activity could save lives, but the researchers also compared survival rates of patients who did or didn't get beta blockers and came up with the successful results.
One reason why beta blockers save lives is that they prevent fatal arrhythmias, Ellison says, but that is not the complete explanation. "It is probably a combination of all of the effects of beta blockers, since the study found not just a specific anti-arrhythmia benefit but a total mortality benefits," she says.
"This is adding to the body of knowledge we already have," says Dr. Robert Bonow, professor of medicine at Northwestern University and president of the American Heart Association. "These drugs are very helpful in patients who have a damaged heart or weak heart function."
Bonow says he would be inclined to prescribe a beta blocker for any heart attack patient. But the evidence of the new study shows that the effect is strongest in cases when the heart is damaged enough to reduce its pumping ability by 40 percent, he says.
What To Do
You can learn about irregular heartbeats and their treatment from the American Heart Association, which also has a page on ways to prevent a second heart attack.
