Aspirin fails to benefit elderly patients for CVD prevention
PARIS — Aspirin did not benefit older patients for the primary prevention of CVD, according to a new analysis from the ASPREE trial presented at the European Society of Cardiology Congress.
As Healio previously reported, in the main results of ASPREE, in older adults, low-dose aspirin did not reduce CVD risk compared with placebo and conferred an increase in risk for major hemorrhage.
The current analyses focused on whether baseline CVD risk influences the effects of aspirin on CV events, disability-free survival and major bleeding in patients from this trial, Christopher M. Reid, professor (research) of clinical epidemiology at Monash University in Melbourne, Australia, said during a presentation.
The researchers stratified participants from the ASPREE cohort by baseline levels of risk as assessed by the Framingham Modified Risk Equation (n = 10,918) and by the American College of Cardiology/American Heart Association Atherosclerotic CVD Pooled Risk Equation (n = 15,825). Although both equations considered nearly the same factors, the Pooled Risk Equation also took ethnicity into account. In addition, the Framingham Modified Risk Equation consisted of participants aged 65 to 74 years, whereas the Pooled Risk Equation included adults up to 79 years old. The Framingham Modified Risk Equation included HF in the list of outcomes. CVD risk for participants 80 years and older (n = 2,928) was based on the presence of multiple conventional CVD risk factors.
Patients in the Framingham Modified Risk Equation group were categorized into tertiles based on mean predicted risk, which ranged from 10.1% to 37.1%. This was also done for the Pooled Cohort Equation group, with a risk ranging from 13.4% to 35.9%.
For both equations, there was an increase in risk across the three tertiles.
“That’s where we’re aware that both of these models, the Framingham and the ASCVD risk [scores], overpredicted the risk in this healthy elderly population, but we certainly were able to see an increased risk in both of those groups,” Reid said during the presentation.
There was no impact of aspirin on CV risk in the lowest tertile of CVD risk according to the Framingham Modified Risk Equation (HR = 1.01; 95% CI, 0.62-1.64). In this group, aspirin conferred an increased risk for major bleeding (HR = 2.6; 95% CI, 1.51-4.48) and a “detrimental impact,” but not a statistically significant one, on the risk for disability, death or dementia (HR = 1.28; 95% CI, 0.94-1.73), Reid said.
When all three tertiles were assessed, the highest tertile of CV risk had fewer CVD events when assigned aspirin vs. placebo (HR = 0.72; 95% CI, 0.54-0.95), but the other two tertiles did not, while the lower two tertiles had increased risk for bleeding if assigned aspirin, but the highest tertile did not, according to the researchers. Aspirin did not have a significant impact on risk for disability, death or dementia in any of the tertiles.
Aspirin did not have an impact on CVD risk prevention in patients in the lowest tertile in the Pooled Risk Equations group (HR = 1.07; 95% CI, 0.67-1.71). The risk for major bleeding significantly increased (HR = 2.3; 95% CI, 1.48-3.58), although there was no effect on the risk for death, disability or dementia (HR = 1.16; 95% CI, 0.91-1.48). In the highest tertile, aspirin lowered risk for CVD events (HR = 0.75; 95% CI, 0.58-0.97) and was associated with numerically higher risk for bleeding (HR = 1.31; 95% CI, 0.99-1.74).
The CV risk in patients aged 80 years and older did not separate as the number of risk factors increased.
“What we did see what irrespective of whether we used a more broader Framingham Study definition, which included not only fatal MI and stroke, but also heart failure, or the more tighter ASCVD definition, we really weren’t able to see a vast improvement in outcomes,” Reid said during the presentation.
There were higher rates of bleeding in all three tertiles in the group of patients 80 years and older. No aspirin treatment effects were seen with regards to the improvement in the rates of death, disability and dementia.
“As a population strategy, findings do not support aspirin for primary prevention in the elderly as the risks outweighed the benefits,” Reid said during the presentation. – by Darlene Dobkowski
Reid CM, et al. Late-Breaking Science in Cardiovascular Pharmacology. Presented at: European Society of Cardiology Congress; Aug. 31 to Sept. 4, 2019; Paris.
Disclosure: Reid reports no relevant financial disclosures.