Aspirin, Beta Blocker Usage Up, But Not Enough
WASHINGTON -- While the use of inexpensive aspirin and beta
blockers by heart patients to prevent death has shown steady
improvement, Duke University Medical Center cardiologists
believe there is still much room for improvement, particularly
in consistency of long-term use.
The medical community needs to focus its attention on
educating physicians and patients on the importance of taking
these medications on a long-term basis, said the cardiologists.
While many clinical trials have consistently proven the ability
of aspirin and beta blockers in forestalling future heart
attacks, the new Duke analysis is the first to link consistent
use of these drugs with improved outcomes.
The researchers found that consistent use of these drugs led
to risk reductions of greater than 40 percent.
"Although most studies have documented the use of these
evidence-based medicines while patients are in the hospital and
at discharge, very few have actually documented the patterns of
use once patients return to their communities," said Duke
Clinical Research Institute cardiologist Kristin Newby,
M.D. She presented the results of the Duke analysis May 16,
2004, at the American Heart Association's 5th scientific forum
on Quality of Care and Outcomes Research in Cardiovascular
Disease and Stroke.
"This is one of the first and largest to evaluate the
long-term usage trends for these important preventative
medications," Newby said.
Newby was able to perform this analysis because the Duke
Databank for Cardiovascular Disease has been collecting
detailed clinical information on all its cardiac
catheterization patients since 1969. Every Duke heart patient
with coronary artery disease is contacted once a year following
discharge from the hospital. Since 1995, researchers began
asking detailed questions about medications.
Specifically, the researchers found that 59 percent of
patients were taking aspirin in 1995, increasing to 83 percent
in 2002. As for beta blockers, the percentage of patients
taking the medication increased from 34 percent to 61 percent.
Those taking both medications increased from 24 percent to 54
percent. However, only 72 percent of patients consistently took
aspirin over this period, only 46 percent a beta blocker and
only 36 percent both drugs.
The analysis also found that patients who consistently took
aspirin had a 45 percent less risk of dying. The mortality risk
was 40 percent less for consistent beta blockers use and 42
percent less for the combination therapy.
"While the progress during that time has been steady,
compliance is still not where it should be," Newby continued.
"We found in our analysis a strong association between
consistent long-term use and lower mortality. We as physicians
have spent a great deal of time studying how best to treat our
patients while in the hospital, so now we need to focus on
better understanding the barriers to improved compliance
outside of acute medical settings."
Ironically, the higher risk patients who stand to benefit
the most from aspirin and beta blocker therapy were the least
likely to be taking aspirin and/or beta blockers.
"Increasing age, diabetes, heart failure and smoking were
associated with a lower likelihood of consistent use of each
agent and their combination, while more recent entry into the
DDCD, receiving a revascularization procedure or use of other
evidence-based medicine predicted higher usage," Newby
The solution to improving the rates of aspirin and beta
blockers should involve behavioral changes for both physicians
and patients, Newby said.
"There are still doctors who are reluctant to prescribe
these drugs to their patients, maybe not realizing that
potential side effects are far outweighed by the benefits," she
said. "It also should be second nature for physicians to see if
certain of their patients should be taking these drugs after
The researchers plan further studies to determine the
factors that lead patients to discontinue the medications. For
aspirin and beta blockers, which have been on the market for
decades and are relatively inexpensive, Newby doesn't believe
that cost is a major factor.
"Part of the problem may be that patients don't realize, or
are not told, that these agents need to be taken on a long-term
basis," she said. "Finding the solution to these issues is the
highest hurdle we face, but it's the one that when solved can
make the biggest impact on outcomes."
Duke is planning other efforts to better understand the
issues surrounding long-term patient compliance with
evidence-based medicines, including a pilot project that will
link Duke cardiologists and pharmacists with physicians and
pharmacists in the community.
Newby's analysis is part of the Centers for Education and
Research on Therapeutics (CERTS) demonstration program, a
national initiative to conduct research and provide education
that advances the optimal use of therapeutics, including drugs,
medical devices, and biological products. The program, which
consists of seven centers and a coordinating center, is
administered as a cooperative agreement by the Agency for
Healthcare Research and Quality (AHQR), in consultation with
the U.S. Food and Drug Administration (FDA). Duke is the
coordinating center for the cardiovascular CERTs.
Other members of the Duke team were Nancy Allen-LaPointe,
Pharm.D., Judith Kramer, M.D., Anita Chen, Bradley Hammill,
Lawrence Muhlbaier, Ph.D., Elizabeth DeLong, Ph.D., and Robert