Common Heart Medicine May Not Be Effective for Some: Study
One expert, however, says beta blockers have proven benefits
TUESDAY, Oct. 2, 2012 (HealthDay News) -- A common type of blood pressure drug called a beta blocker may not prevent heart attack, stroke or death, a new study suggests.
This is particularly true for patients at risk for heart disease, patients who have heart disease but who have never had a heart attack, or patients who have had a heart attack, the researchers added.
"We found in this group of patients there was no benefit from beta blockers," said lead researcher Dr. Sripal Bangalore, assistant professor of cardiology at the New York University School of Medicine.
Instead, among some patients, beta blockers increased the risk of a bad outcome, he said.
Specific types of patients taking the drugs had a higher risk of death or hospitalization for a heart procedure. One group, however, had a lower risk of being hospitalized.
These findings may be due in part to the nature of beta blockers themselves, Bangalore said. Compared to other blood pressure drugs, beta blockers are less effective and are not considered first-line treatment, he said.
In addition, beta blockers increase the risk of diabetes and increase cholesterol levels, Bangalore said.
"The combination of all these may be responsible for the worse outcomes," he said.
Bangalore, however, believes beta blockers -- which include carvedilol (Coreg), propranolol (Inderal) and atenolol (Tenormin) -- do have a role in treating heart failure, irregular heart rhythms and migraines.
"This study is not about patients who have heart failure, this is not about patients who have arrhythmia or migraine," he said. "For all these patients, beta blockers are beneficial."
Bangalore said he doesn't want patients to stop taking beta blockers, but rather to talk with their doctor about why they are taking them and see if they should be switched to an alternative drug.
The report was published in the Oct. 3 issue of the Journal of the American Medical Association.
For the study, Bangalore's team collected data on more than 44,000 people who were part of an international study and registry focused on risk for atherosclerosis, or hardening of the arteries.
Among these patients, more than 14,000 had had a heart attack, more than 12,000 had heart disease but not a heart attack, and more than 18,000 had risk factors for heart disease.
For those with heart disease or who had a heart attack, the researchers found no difference between those taking beta blockers and those not taking them when it came to death, heart attack or stroke. The rates for being hospitalized for a cardiac procedure, however, were higher among those taking beta blockers.
Among patients who had risk factors for heart disease, those taking beta blockers were at higher risk for dying or being hospitalized for a cardiac procedure, compared to those not taking them, the researchers noted. They were, however, not at higher risk of heart attack or stroke.
Patients who had a recent heart attack and who were taking beta blockers had a lower risk of being hospitalized, the study found.
One cardiologist said he didn't think this study was definitive because it had limitations, and added that the finding runs counter to findings from some clinical trials.
"Beta blockers have been demonstrated in randomized clinical trials to remarkably reduce mortality and prevent recurrent events in patients after a heart attack and those with heart failure," said Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles, and a spokesman for the American Heart Association.
Beta blockers have been less well studied in patients with stable coronary artery disease and those with risk factors for coronary artery disease in terms of their effect on heart attack and death, he said.
This new observational study did not find that use of beta blockers was associated with better outcomes, Fonarow said.
"However, this registry was not designed to evaluate the role of beta blockers and vital data including blood pressure, heart rate, contraindications and intolerance to beta blockers," he said. "Specific agent [beta-blocker] and dose were not available and could not be adjusted for."
"As a result of these limitations, these findings add little to the current evidence," Fonarow concluded. "Beta blockers continue to be guideline-recommended and should continue to be prescribed for patients long-term after a heart attack."
To learn more about heart disease, visit the American Heart Association.