A large clinical trial found that taking low-dose aspirin every day failed to reduce the risk of heart disease, physical disability, and dementia in healthy older men and women. In addition, regular aspirin use was linked with a significant risk of bleeding, particularly in the gastrointestinal tract and brain. “Millions of healthy older adults take a daily aspirin without clear evidence that doing so will be beneficial,” says Basil Eldadah, MD, chief of the geriatrics branch at the National Institute on Aging (NIA) in Bethesda, Maryland. “This study has shown us that overall the benefits of regular aspirin use do not outweigh its harms.” Dr. Eldadah, who oversaw the trial for the NIA, adds that the results do not apply to people who have been prescribed aspirin for a medical condition, such as cardiovascular disease, that warrants daily aspirin use.
Slight, Surprising Rise in Cancer Deaths
Published September 16, 2018, in The New England Journal of Medicine, this investigation (called Aspirin Reducing Events in the Elderly, or ASPREE) followed 19,114 participants from the United States and Australia who were age 70 or older (65 or older among U.S. blacks and Hispanics). One-half received 100 milligrams of aspirin per day, while the others received a placebo. At the study’s start, all participants were free of dementia, physical disability, and medical conditions that would require aspirin use. After a median follow-up of 4.7 years, researchers observed that the rate of patient survival without dementia or disability was about the same in each group. Yet the overall death rate in the aspirin group was slightly higher (5.9 percent versus 5.2 percent taking placebo). Most of the deaths among aspirin users were due to cancer, but study authors caution that the difference is small and the numbers may have been due to chance. “The increase in cancer deaths in study participants in the aspirin group was surprising, given prior studies suggesting aspirin use improved cancer outcomes,” Leslie Ford, MD, associate director for clinical research with the division of cancer prevention at the National Cancer Institute in Bethesda, Maryland, said in a statement. “Analysis of all the cancer-related data from the trial is underway, and until we have additional data these findings should be interpreted with caution.” Scientists also observed that rates of coronary heart disease, nonfatal heart attacks, and fatal and nonfatal ischemic stroke were similar in the aspirin and the placebo groups. Furthermore, 361 people (3.8 percent) on aspirin suffered clinically significant bleeding — hemorrhagic stroke, bleeding in the brain, gastrointestinal hemorrhages, or hemorrhages at other sites that required transfusion or hospitalization — compared with 265 (2.7 percent) taking the placebo.
Study Challenges Common Practices
Many physicians and cardiologists in the past have recommended that men over 50 and women over 65 should consider taking an aspirin daily, according to Sarah Samaan, MD, a cardiologist with Baylor Regional Medical Center in Plano, Texas. Currently, the U.S. Preventive Services Task Force advises that adults ages 50 to 59 who have a 10 percent or greater 10-year heart disease risk take low-dose aspirin for the primary prevention of cardiovascular disease (CVD) and colorectal cancer (CRC).
Aspirin Still Vital for Heart Disease Patients
Dr. Samaan emphasizes that the study results do not apply to patients who already have heart disease. “When the study was published, we had calls to our practice from people who have known heart disease asking if they should stop their aspirin,” says Samaan. “They should absolutely not stop taking aspirin unless their doctor advises them to do so!” The American Heart Association reports that regular aspirin use can cut the chances of a second heart attack, stroke, or cardiovascular-related death by about 25 percent. For stroke survivors, it reduces the odds of a second event by about 22 percent. Although none of the study participants had had any cardiac events, they were not without health problems, notes Samaan. Almost three-quarters had hypertension, more than 40 percent were current or former smokers, 1 in 3 had dyslipidemia (high cholesterol or triglycerides), nearly three-quarters were overweight or obese, and about 10 percent had diabetes. “Still, there was not a statistically significant benefit from aspirin for people who had these risk factors,” says Samaan. She points out that one risk factor not examined in the study may warrant the use of aspirin. “If we find plaque buildup in the heart, then we often will recommend aspirin,” she says.
Study Limitations, More Analysis
As far as study limitations are concerned, Eldadah says that the investigation focused mainly on starting aspirin in older age, and does not provide definitive answers about individuals who have already been taking aspirin regularly. He adds that the results are based on an average across the large number of subjects enrolled in ASPREE, so the results may not apply to every older adult. “The investigators are conducting additional analyses of the data to help us better understand the current findings,” says Eldadah. “In addition, they are continuing to follow participants enrolled in ASPREE, which will help us better understand the longer-term effects of regular aspirin use in healthy older adults.”
