VA Researcher Questions Daily Use of Drug in Many Patients

By Brenda L. Mooney

Anthony Bavry, MD

GAINESVILLE, FL — Since the mid-1980s, aspirin has been used as a preventive drug for cardiovascular disease. In fact, the U.S. Preventive Services Task Force (USPSTF) says that about 40% of American adults over 50 currently take a daily aspirin to prevent heart attacks or strokes.

Some percentage of those patients might be putting themselves at unnecessary risk without much benefit, however, suggested a new study led by a VA researcher.

Anthony Bavry, MD, a cardiologist at the North Florida/South Georgia Veterans Health System, and colleagues found that aspirin appears to provide little or no benefit for certain patients who have plaque buildup in their arteries.

While aspirin reduces blood clots, the researchers reviewed the health histories of more than 33,000 patients with atherosclerosis to find that acetylsalicylic acid is only marginally beneficial for those who have had a previous heart attack, stroke or other blood-flow issues involving arteries.

For atherosclerosis patients without prior heart attack or stroke, the common drug showed no benefit, according to the article in Clinical Cardiology.1

The research was observational, but Bavry, who also is a professor at the University of Florida School of Medicine, suggested that the results call into question the extremely widespread use of aspirin for cardiovascular prevention.

“Aspirin therapy is widely used and embraced by cardiologists and general practitioners around the world,” Bavry pointed out. “This takes a bit of the luster off the use of aspirin.”

“The cardiology community needs to appreciate that aspirin deserves ongoing study,” he added. “There are many individuals who may not be deriving a benefit from aspirin. If we can identify those patients and spare them from aspirin, we’re doing a good thing.”

Bavry emphasized that the drug remains essential in emergency situations such as an ongoing heart attack or stroke, when patients should immediately take aspirin.

Enrolled in the nationwide study, which used data from late 2003 to mid-2009, were patients at least 45 years old with coronary artery disease, cerebrovascular disease or peripheral vascular disease.

In the prior ischemic event group, the risk of the first occurrence of cardiovascular death, myocardial infarction (MI), or stroke at a median of 41 months was marginally lower with aspirin users vs. nonusers—15.2% vs 15.8%; hazard ratio [HR]: 0.81.

For those atherosclerosis patients who had not experienced a heart attack or stroke, aspirin appeared to have no effect. The risk of cardiovascular death, heart attack and stroke was 10.7% aspirin users and 10.5% for non-users, for an HR of 1.03.

Who Benefits?

The one group showing significant benefit from aspirin use included patients who had a coronary bypass or stent but no history of stroke, heart attack or arterial blood-flow condition, study authors noted.

“Benefit was not observed among the cohort with stable atherosclerosis, but no prior ischemic event; however, subgroup analysis suggested that individuals with prior coronary revascularization might derive benefit from aspirin,” according to the report.

This isn’t the first time the investigators have questioned the orthodoxy on cardiovascular prevention. A previous analysis of the REACH registry, published earlier this year, had indicated that stable patients with previous MI did not benefit from β-blocker use,] which had been the recommendation for decades in patients with prior MI.2

Now, the current analysis using data from the REACH registry raises issues on aspirin and how effectively it works in atherosclerosis patients.

Bavry said discerning aspirin’s effectiveness for various patients is also important, because the medicine can create complications, including gastrointestinal bleeding and, less frequently, bleeding in the brain.

While the Food and Drug Administration agrees with those risks, it states on its website, “The available evidence supports the use of aspirin for preventing another heart attack or stroke in patients who have already had a heart attack or stroke or have other evidence of coronary artery disease, such as angina or a history of a coronary bypass operation or coronary angioplasty. Reducing the risk of additional heart attacks or strokes is known as secondary prevention. In patients who have had such cardiovascular events, the known benefits of aspirin for secondary prevention outweigh the risk of bleeding.”

First proposed during the 1950s, the concept of using aspirin to prevent clotting diseases gained new momentum in the 1960s and was tested in a clinical trial ending in 1973.

During the mid-1980s, the FDA and much of the medical community became convinced after a meta-analysis showed effectiveness with relative certainty.

The recent study marks the second time this year that Bavry and his collaborators have published research raising questions about aspirin therapy. In April, the group provided evidence that the drug might not provide cardiovascular benefits for people with peripheral vascular disease.3

Bavry said the topic needs more research and cautioned patients with atherosclerosis or peripheral vascular disease not to quit aspirin therapy on their own but to discuss it with their physicians.

  1. 1. Bavry AA, Elgendy IY, Elbez Y, Mahmoud AN, Sorbets E, Steg PG, Bhatt DL; REACH Registry Investigators. Aspirin and the risk of cardiovascular events in atherosclerosis patients with and without prior ischemic events. Clin Cardiol. 2017 May 18. doi: 10.1002/clc.22724. [Epub ahead of print] PubMed PMID: 28520215.
  2. Bangalore S , Steg G , Deedwania P , et al. REACH Registry Investigators. β-Blocker use and clinical outcomes in stable outpatients with and without coronary artery disease. JAMA . 2012;308:1340–1349
  3. 3. Mahmoud AN, Elgendy AY, Rambarat C, Mahtta D, Elgendy IY, Bavry AA. Efficacyand safety of aspirin in patients with peripheral vascular disease: An updatedsystematic review and meta-analysis of randomized controlled trials. PLoS One.2017 Apr 12;12(4):e0175283. doi: 10.1371/journal.pone.0175283. eCollection 2017. PubMed PMID: 28403216; PubMed Central PMCID: PMC5389721.