Many Patients With Coronary Artery Disease Still Fail to Use Aspirin Therapy
DURHAM, N.C. – Despite substantial evidence that aspirin
saves lives and reduces the risk of heart attacks, a study
conducted by Duke University Medical Center researchers
indicated that, as of 1999, one in five people with coronary
artery disease still did not take aspirin regularly.
In the study, published in the March 15, 2002, issue of the
American Journal of Cardiology, 80.5 percent of patients
questioned used aspirin in 1999. The 25,049 patients involved
in the study, who were pulled from the Duke Databank for
Cardiovascular Disease and had coronary artery disease
diagnosed by angiography at Duke, were questioned on their
aspirin use between 1995 and 1999.
While the 80.5 percent figure was a substantial increase
from the 59.2 percent of patients using aspirin in 1995, Robert
Califf, M.D., the study's lead author, said the percentage seen
in the 1999 data was "disappointingly low" considering the
wealth of information supporting aspirin's benefits in addition
to it being inexpensive and available without prescription.
"Given the strong evidence for the benefit of aspirin
combined with its low cost, the failure to achieve greater than
95 percent use of aspirin, or other antithrombotic therapy in
this population, is disappointing. Adherence should have been
greater," said Califf, who is director of the Duke Clinical Research
Institute. He and his colleagues plan further studies to
continue to follow the trend in aspirin use after 1999, the
latest year for which data were available.
The study also showed that coronary artery disease patients
who never used aspirin had nearly twice the risk of death (risk
ratio of 1.85) than those patients who used aspirin, Califf
Men were more likely than women to be taking aspirin,
according to the study results. Higher use also was seen among
younger patients, nonsmokers and patients with a prior heart
attack or who underwent revascularization, a procedure in which
clogged coronary arteries were unblocked. Higher use also was
recorded in patients seeing cardiologists for follow-up care
and among patients whose physicians referred a large number of
patients for coronary angiography at Duke.
Those patients who were less likely to be using aspirin
therapy included those with heart failure, diabetes and
Califf especially urged patients with diabetes to consult
their physicians concerning the use of aspirin; since previous
research findings have emphasized the substantial benefits
aspirin use can offer these patients.
"Too many patients without contraindications to aspirin fail
to take it regularly. The health care system currently lacks
effective methods to ensure that patients who have coronary
artery disease have adequate follow-up concerning aspirin use,"
A small proportion of people should avoid aspirin use,
Califf said. These include people with allergies to aspirin and
with a history of significant gastrointestinal bleeding or
As recently as January 2002, the U.S. Preventative Services
Task Force, part of the Public Health Service, strongly
that doctors discuss aspirin therapy with their patients,
especially those at risk of coronary artery disease. These
patients include men over the age of 40, postmenopausal women
and younger people with risk factors for heart disease
(smoking, diabetes, hypertension).
Every year, more than 1 million Americans die from heart
attacks and other forms of coronary artery disease.
"Physicians and patients simply may forget this ubiquitously
available treatment," Califf said, adding that further
evaluation is needed on why patients fail to take aspirin.
"There is an absence of mechanisms and systems to remind
patients about the need to adhere to routine secondary
Califf said Duke soon will implement systems that will
provide a safety net of reminders for patients regarding
aspirin use. "This study was one of the things that helped
prompted us to look into this," he said.
Califf noted that the number of patients using aspirin in
this study might be higher than other populations because of
the amount of data maintained by the Duke Databank for
The study was conducted under the auspices of the Center for Education and
Therapeutics (CERTs), a research program administered by
the Agency for Healthcare
Research and Quality (AHRQ) in consultation with the
federal Food and Drug Administration to conduct research and
provide education that will advance the optimal use of drugs,
medical devices and biological products. The study was
supported in part by a grant from the AHRQ.
Joining Califf in the study were Duke colleagues Elizabeth
DeLong, Ph.D., Truls Ostbye, M.D., Lawrence Muhlbaier, Ph.D.,
Anita Chen, Bradley Hammill, Charles McCants, Judith Kramer,
M.D., and Nancy LaPointe, PharmD.