By Linda Carroll

(Reuters Health) – – Many Americans regularly take aspirin without a doctor’s recommendation, believing it will protect their hearts, a new study finds. The problem is that for those who don’t already have heart disease, aspirin comes with some dangerous side effects, such as brain bleeds, experts say.

While doctors used to support daily consumption of low-dose aspirin to prevent heart attacks and stroke, three major clinical trials in early 2018 found the risks of the drug outweighed any benefits in people who did not already have heart disease. The trials led the American Heart Association and the American College of Cardiology to change clinical practice guidelines and to warn that any benefit from taking a daily low-dose aspirin would be more than offset by the danger of internal bleeding and other side effects in people considered to be at low or moderate risk for heart disease.

That’s why the findings of the new study, published in Annals of Internal Medicine, are so worrisome, said coauthor Dr. Christina Wee, a researcher and general internist at Beth Israel Deaconess Medical Center and an associate professor of medicine at the Harvard Medical School.

“We found that one quarter of adults 40 and older who don’t have heart disease are taking aspirin regularly,” Wee said “And more concerning, one half of adults over age 70 who don’t have heart disease or stroke are taking aspirin regularly. Aspirin will raise the risk of bleeding and ulcer development regardless of age, but the older you get the more at risk you are anyway.”

While the data used in the study were collected before the new guidelines came out, “we suspect things haven’t changed much,” Wee said.

The data came from the Sample Adult component of the 2017 National Health Interview Survey (NHIS), a nationally representative in-person household survey of health and disability in U.S. adults.

Wee and her colleagues analyzed responses from 14,328 survey participants whose average age was 57.5 years. Among those aged 40 and older who did not have heart disease, 23.4% reported taking daily aspirin to protect their hearts. Extrapolated, that would work out to be approximately 29 million Americans. Of these, 22.8% (representing 6. 6 million) were doing so without their doctor’s recommendation.

Nearly half (44.6%) of adults aged 70 or older without cardiovascular disease said they were using aspirin to prevent heart disease. And having a history of ulcers didn’t seem to prevent these seniors from taking a daily aspirin.

Overall, Wee and her colleagues estimate that nearly 30 million U.S. adults aged 40 and older are using aspirin to prevent cardiovascular disease, including nearly half of seniors who said they did not have heart disease and one quarter of adults with no heart disease but a history of ulcers.

Wee is not recommending that everyone stop taking aspirin. Rather, she said, before making any changes, people should discuss the issue with their doctors. That’s because it can be difficult to calculate one’s exact risk of heart disease, Wee said, noting that aspirin is still recommended for some.

Further, Wee said, “I want to emphasize that these new guidelines are referring only to people who don’t have heart disease, haven’t had a stroke and don’t have some other compelling reason to be on aspirin.”

The new findings “are certainly a call to action,” said Dr. Prashant Vaishnava, a cardiologist at The Mount Sinai Hospital and director of Quality and Inpatient Services for Mount Sinai Heart, in New York City. “It highlights that there are more than six million people taking low dose aspirin every day without a physician’s recommendation.”

A separate study recently published in JAMA Neurology should give those folks pause, Vaishnava said. “That was a meta-analysis of patients without symptoms of heart disease,” she said. “It showed an association between daily aspirin use and intracranial hemorrhage. Certainly there are harms associated with indiscriminate aspirin use for primary prevention in low risk populations.”

SOURCE: Annals of Internal Medicine, online July 22, 2019.