If one CVD event was considered to be equivalent to one major bleed, 2.5% of women and 12.1% of men without CVD were likely to have a 5-year net benefit from an aspirin regimen, researchers reported in the Annals of Internal Medicine.
If one CVD event was considered to be equivalent to two major bleeds, the percentage of people without CVD with a net benefit from a 5-year aspirin regimen rose to 21.4% of women and 40.7% of men.
Those who would benefit from aspirin “could be identified by using a personalized benefit-harm analysis, and sharing the findings of such an analysis with patients might support more informed decision-making,” Vanessa Selak, MBChB, PhD, senior lecturer in epidemiology, biostatistics and public health at the University of Auckland, New Zealand, and colleagues wrote.
Selak and colleagues analyzed 245,028 people (44% women) who were part of the PREDICT electronic decision-support program used in certain primary care practices in New Zealand. All participants were aged 30 to 79 years, did not have CVD at baseline and received a CVD risk assessment between 2012 and 2016.
The researchers calculated the proportional effect of aspirin on CVD and bleeding risk using data from a meta-analysis of 13 randomized controlled trials of aspirin for primary prevention. From there, the researchers developed a personalized prediction model, calculating the net effect by subtracting the predicted reduction in CVD events from the predicted increase in major bleeds during 5-year aspirin use.
The model assumed one CVD event was equivalent to one major bleed, but a sensitivity analysis was conducted assuming one CVD event was equivalent to two major bleeds.
Participants were stratified by those who had net benefit (net effect score of less than –1), equipoise (net effect score of –1 to 1) or net harm (net effect score of 2 or more). In some analyses, patients were further stratified into substantial net benefit (net effect score of –5 or less) or substantial net harm (net effect score of 5 or greater).
If one CVD event was considered to be equivalent to one major bleed, 2.5% of women and 12.1% of men without CVD were likely to have a 5-year net benefit from an aspirin regimen.
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Compared with those who had net harm from aspirin use, those who had net benefit were older had greater baseline risk for CVD and bleeding, had higher systolic BP and had a higher ratio of total cholesterol to HDL, Selak and colleagues wrote.
The net benefit group compared with the net harm group also were more likely to be current smokers, to have diabetes and to be taking BP or lipid-lowering medication, according to the researchers.
In contrast, they wrote, the net harm group was more likely than the net benefit group to have a history of cancer, major bleeding, peptic ulcer disease or alcohol-related conditions and to be taking drugs for peptic ulcer disease or other drugs known to increase bleeding risk.
“For some persons without CVD, aspirin is likely to result in net benefit,” Selak and colleagues wrote.
Balancing risks, benefits
In a related editorial, John B. Kostis, MD, director of the Cardiovascular Institute of New Jersey, associate dean for cardiovascular research, John G. Detwiler Professor of Cardiology and professor of medicine and pharmacology at Rutgers Robert Wood Johnson Medical Center, wrote: “Establishing firm, evidence-based recommendations for aspirin use in primary prevention is difficult. It seems reasonable to recommend aspirin for the primary prevention of CVD in select patients, including those who are at high risk for CVD, provided that the bleeding risk is low, as evidenced by a history of bleeding and comorbid conditions.” – by Erik Swain
Disclosures: The authors report no relevant financial disclosures.