AMD–Aspirin Link: Latest Hint Not the Last Word
Drug & Reference Information
Australian researchers analyzing data from a
large, population-based eye study reported this week finding a
statistically significant association between 15 years of regular
aspirin use and the development of neovascular age-related macular
degeneration (AMD).
Compared with others in the Blue Mountains Eye Study, participants who reported using aspirin at least once a week were twice as likely as nonusers to develop neovascular AMD in the subsequent 15 years, according to the report published online January 21 by JAMA Internal Medicine (formerly Archives of Neurology).
The odds ratio for developing wet AMD was 2.46 among the aspirin users (95% confidence interval [CI], 1.25 - 4.83), after adjustment for several possible confounding variables (age, sex, smoking, history of cardiovascular disease, systolic blood pressure, and body mass index). There was no such association for geographic atrophy, Gerald Liew, PhD, from the Centre for Vision Research, Department of Ophthalmology, University of Sydney, and the Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia, and colleagues report.
The report marked the third large study in the last year to suggest an association between aspirin use and neovascular AMD. Most recently, similar figures were reported for an analysis of data from the Beaver Dam Eye Study.
Frightened to Death?
Continuing publicity about the studies has heightened concerns that elderly people might be frightened literally to their deaths if they stop taking the aspirin they need to prevent heart attack or stroke, said Emily Y. Chew, MD, PhD, deputy director of the Division of Epidemiology and Clinical Applications at the National Eye Institute, Bethesda, Maryland.
"It's a public health issue, because it's clear that the protective effect from aspirin is high. People are going to die because of not taking aspirin for their heart disease. My patients are scared to death right now," Dr. Chew said to Medscape Medical News.
Even if aspirin use were confirmed as an AMD risk factor using more robust study data, Dr. Chew said, it already is apparent that the risk would be quite small in absolute terms, at about 1% for aspirin users, and 0.5% for nonusers.
" 'Doubling' the risk sounds terrible," she said. "But the real risk for late-stage AMD in these people who took aspirin [in the Beaver Dam Study] is 1%, vs half a percent for those who didn't, which is not clinically meaningful."
Dr. Chew noted that her preliminary look at data from a carefully controlled clinical trial that she leads found no extra risk for AMD in aspirin users. On the contrary, aspirin users in the second Age-Related Eye Diseases Study (AREDS2), in which Dr. Chew is principal investigator, had a lower risk for neovascular AMD than control patients, with an odds ratio of 0.61 (95% CI, 0.49 - 0.75; P < .0001), she found in this early analysis, which has been presented at meetings but not yet submitted for publication.
A senior coauthor of the current study acknowledged that the published evidence for an aspirin–AMD link remains inconclusive.
"Our study only generates a hypothesis of a possible side effect of aspirin use, but this needs to be confirmed by future studies. However, any single study adds to the evidence that we have so far," said Jie Jin Wang, PhD, also from the Centre for Vision Research, Department of Ophthalmology, University of Sydney, and the Centre for Eye Research Australia, University of Melbourne, in an interview with Medscape Medical News.
In a commentary that accompanied the Australian study, 2 cardiologists, Sanjay Kaul, MD, and George A. Diamond, MD, from the Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California, urged clinicians to be move cautiously in response as further research continues.
"From a purely science-of-medicine perspective, the strength of evidence is not sufficiently robust to be clinically directive," they write. "However, from an art-of-medicine perspective, based on the limited amount of available evidence, there are some courses of action available to the thoughtful clinician."
They suggest a middle course, individualized to the patient's needs:
JAMA Intern Med. Published online January 21, 2013. Article full text, Commentary full text
Compared with others in the Blue Mountains Eye Study, participants who reported using aspirin at least once a week were twice as likely as nonusers to develop neovascular AMD in the subsequent 15 years, according to the report published online January 21 by JAMA Internal Medicine (formerly Archives of Neurology).
The odds ratio for developing wet AMD was 2.46 among the aspirin users (95% confidence interval [CI], 1.25 - 4.83), after adjustment for several possible confounding variables (age, sex, smoking, history of cardiovascular disease, systolic blood pressure, and body mass index). There was no such association for geographic atrophy, Gerald Liew, PhD, from the Centre for Vision Research, Department of Ophthalmology, University of Sydney, and the Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia, and colleagues report.
The report marked the third large study in the last year to suggest an association between aspirin use and neovascular AMD. Most recently, similar figures were reported for an analysis of data from the Beaver Dam Eye Study.
Frightened to Death?
Continuing publicity about the studies has heightened concerns that elderly people might be frightened literally to their deaths if they stop taking the aspirin they need to prevent heart attack or stroke, said Emily Y. Chew, MD, PhD, deputy director of the Division of Epidemiology and Clinical Applications at the National Eye Institute, Bethesda, Maryland.
"It's a public health issue, because it's clear that the protective effect from aspirin is high. People are going to die because of not taking aspirin for their heart disease. My patients are scared to death right now," Dr. Chew said to Medscape Medical News.
Even if aspirin use were confirmed as an AMD risk factor using more robust study data, Dr. Chew said, it already is apparent that the risk would be quite small in absolute terms, at about 1% for aspirin users, and 0.5% for nonusers.
" 'Doubling' the risk sounds terrible," she said. "But the real risk for late-stage AMD in these people who took aspirin [in the Beaver Dam Study] is 1%, vs half a percent for those who didn't, which is not clinically meaningful."
Dr. Chew noted that her preliminary look at data from a carefully controlled clinical trial that she leads found no extra risk for AMD in aspirin users. On the contrary, aspirin users in the second Age-Related Eye Diseases Study (AREDS2), in which Dr. Chew is principal investigator, had a lower risk for neovascular AMD than control patients, with an odds ratio of 0.61 (95% CI, 0.49 - 0.75; P < .0001), she found in this early analysis, which has been presented at meetings but not yet submitted for publication.
A senior coauthor of the current study acknowledged that the published evidence for an aspirin–AMD link remains inconclusive.
"Our study only generates a hypothesis of a possible side effect of aspirin use, but this needs to be confirmed by future studies. However, any single study adds to the evidence that we have so far," said Jie Jin Wang, PhD, also from the Centre for Vision Research, Department of Ophthalmology, University of Sydney, and the Centre for Eye Research Australia, University of Melbourne, in an interview with Medscape Medical News.
In a commentary that accompanied the Australian study, 2 cardiologists, Sanjay Kaul, MD, and George A. Diamond, MD, from the Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California, urged clinicians to be move cautiously in response as further research continues.
"From a purely science-of-medicine perspective, the strength of evidence is not sufficiently robust to be clinically directive," they write. "However, from an art-of-medicine perspective, based on the limited amount of available evidence, there are some courses of action available to the thoughtful clinician."
They suggest a middle course, individualized to the patient's needs:
- Secondary prevention: Maintain the status quo, because there is strong evidence that its benefits outweigh the risks.
- Primary prevention: Carefully weigh potential risks and benefits. In patients who, under current guidelines, are eligible for treatment because of their 10-year risk of myocardial infarction or stroke, "the presence or absence of strong risk factors for neovascular AMD might tilt treatment decisions in one direction or the other."
- Other uses of aspirin: Be cautious in recommending long-term aspirin to other patients, such as those requiring pain control.
JAMA Intern Med. Published online January 21, 2013. Article full text, Commentary full text
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