DURHAM, N.C. -- Fewer than half of the patients who were prescribed beta blocker drugs following a heart attack and who had some prescription drug coverage were regularly taking them during the first year after leaving the hospital, according to a Duke University Medical Center analysis of more than 17,000 patients nationwide.
This low rate of adherence is disturbing, since numerous large-scale clinical trials have proven that beta blockers can reduce the risk of future heart attacks, the researchers said. They said the finding also suggests that cost may not be the only issue that influences whether heart attack patients continue to take the drugs.
Beta blockers blunt the normal stimulatory effects of the hormones epinephrine and norepinephrine on the heart, thereby reducing stress on the heart. The drugs also limit the increase in heart rate and reduce the heart's need for oxygen when people exert themselves.
In the study, the researchers found that only 45 percent of heart attack patients regularly took beta blockers during the first year after leaving the hospital. The biggest percent drop in adherence occurred during the initial months after discharge, suggesting that physicians need to step up efforts during this period to improve usage rates, the researchers said.
In particular, younger women with commercial insurance were less likely to continue taking beta blockers following a heart attack, compared to men their age and to older women, the study found.
"In the population of patients we studied with health insurance and prescription drug coverage, we found adherence to beta blockers during the first year following a heart attack to be quite poor, indicating that factors other than the cost of the medicine are important to long-term adherence," said study leader Judith Kramer, M.D., an associate professor at the Duke University Medical Center.