If you’re over 70 years of age and healthy, don’t take low-dose aspirin: it won’t prolong your disability-free survival, even if you’re at the highest risk for cardiovascular disease (CVD), according to researchers who presented their findings at the European Society of Cardiology Congress 2019 on August 31 in Paris, France.
“An ever-increasing number of people reach the age of 70 without overt cardiovascular disease. This analysis suggests that improved risk prediction methods are needed to identify those who could benefit from daily low-dose aspirin,” said cardiovascular epidemiologist Christopher Reid, PhD, professorial research fellow, Curtin University, Perth, Australia, who made the presentation on behalf of the research team.
This conclusion builds on research—the Aspirin in Reducing Events in the Elderly (ASPREE) trial—that these authors published last year. In that randomized, placebo-controlled trial, low-dose (100 mg) daily aspirin did not extend disability-free survival (defined as the absence of dementia, persistent physical disability, or death) in people aged 70 years or over with no known CVD, nor did aspirin significantly lower CVD risk in these patients. Instead, aspirin led to a higher rate of major bleeding compared with placebo.
No survival benefit
Aspirin has been used for centuries for its medicinal properties. But in recent years, preventative use of aspirin has become widespread, even in people who have no medical indication for it.
In the current study, the researchers investigated whether patients’ baseline CVD risk could affect their disability-free survival. The investigators also conducted analyses on all-cause mortality, major hemorrhage, and prevention of CVD.
Using data from 19,114 participants in the ASPREE trial, the investigators calculated 10-year CVD risk scores for all participants and then sorted the participants into three groups: low CVD risk, intermediate CVD risk, and high CVD risk. The researchers also analyzed rates of disability-free survival, mortality, major bleeding, and cardiovascular disease for each risk group, and compared outcomes between those taking aspirin and placebo.
For participants with the lowest CVD risk, aspirin provided no benefit for disability-free survival or cardiovascular disease. This group also had the highest likelihood for bleeding.
On the other hand, those with the highest cardiovascular risk had lower CVD rates on aspirin (HR: 0.72-0.75) but similar rates of bleeding. Nevertheless, reduced cardiovascular events didn’t result in significantly improved disability-free survival in these participants (HR: 0.86-0.89).
“The findings emphasize that the risk-benefit trade-off for aspirin use in healthy older men and women varies across levels of cardiovascular risk,” Dr. Reid said. “It also indicates that the reduction in CVD events in the highest risk groups using current stratification methods does not identify individuals in whom this advantage translates into longer disability-free survival.”
Despite the inauspicious results, the investigators are continuing this line of research in an ASPREE longitudinal follow-up study, which will also include participants’ genetic and biomarker information. Dr. Reid indicated that the team will have to look even deeper for more refined approaches to predicting CVD risk.
“Based on the results of the main ASPREE trial, daily low-dose aspirin cannot be recommended in healthy people over 70—even in those at the greatest CVD risk,” he concluded. “Today’s analysis indicates that more refined methods are needed to pinpoint a subgroup who might gain from preventive therapy.”