Should You Take Aspirin to Prevent a Heart Attack?

For years, many people have taken a low-dose aspirin every day to reduce the risk of heart attacks and strokes — with their doctor’s blessing. But following new evidence that a daily “baby” aspirin (75-100 mg) may have more risks than benefits for some patients, the U.S. Preventive Services Task Force is revising its aspirin recommendation from 2016.

It now advises that many patients should not start taking low-dose aspirin, and that those who are on it should speak with their doctor.

Aspirin, an over-the-counter pain reliever, is also a blood-thinning medication. It is able to help prevent blood from forming harmful clots that can block blood flow in the heart or neck arteries, triggering a heart attack or causing a stroke. However, aspirin can also increase the risk of dangerous bleeding, says Dr. Ajay J. Kirtane, interventional cardiologist and director of cardiac catheterization laboratories at NewYork-Presbyterian/Columbia University Irving Medical Center.

“Unfortunately, nothing is free,” Dr. Kirtane says. “The proven benefit of aspirin in prevention of heart attacks needs to be balanced against an increase in bleeding complications. For individual patients, we need to look at both the bleeding risk and heart attack prevention together.”

The new recommendations apply only to those who haven’t started taking aspirin. If you currently take aspirin to prevent heart attacks and strokes, Dr. Kirtane suggests talking to your doctor about your risks. Don’t stop taking aspirin without your doctor’s approval.

According to Dr. Kirtane, the biggest concerns with aspirin are gastrointestinal bleeding and bleeding in other areas of the body, including bleeding in the brain, which can lead to a certain type of stroke. “Although aspirin has a protective effect against clotting-related (ischemic) strokes, it can also increase the risk of bleeding-related (hemorrhagic) strokes,” he says.

The guidelines suggest that people in their 40s and 50s should not start aspirin to prevent heart attacks and strokes as they might have in the past. “Even in higher-risk patients, like those with diabetes whose cardiovascular risk we would normally be very concerned about, it turns out that the protective effect of aspirin in preventing a first cardiac event was not so pronounced and the bleeding risk is always present,” says Dr. Kirtane, who is also a professor of medicine at Columbia University Vagelos College of Physicians and Surgeons.

Around age 60, the risk of bleeding complications rises further. The new guidelines more strongly discourage starting aspirin in older patients for prevention of first cardiac events, although there may be exceptions for those with “extraordinarily high cardiovascular risks,” says Dr. Kirtane. “At the end of the day, these decisions have to be individualized,” he says.

It’s a different story for people who have already experienced a cardiovascular event like a heart attack or chest pain caused by artery blockages even while resting (unstable angina, which can lead to a heart attack), or have had cardiac interventions like stent procedures to open blocked arteries. “This new aspirin guidance certainly does not apply to patients who have had heart attacks or those with established vascular disease or stents,” Dr. Kirtane says. In those patients, the protection of aspirin more often outweighs the bleeding risks.

Why the change? Earlier studies may not have paid as much attention to the bleeding complications, Dr. Kirtane explains. Current research paints a more complex picture. “In some cases, it turns out that the bleeding events are more significant than the prevention of the heart event,” he says.

For instance, taking a 100 mg aspirin every day was associated with a 12% decrease in the rate of serious cardiac events compared to people taking a placebo pill, according to a 2018 trial of more than 15,000 people with diabetes published in The New England Journal of Medicine (NEJM). But those on aspirin saw a 29% leap in major bleeding events. A similar NEJM study of over 19,000 healthy people age 70 and older showed that aspirin had no benefits for the heart and a higher bleeding risk. At the same time, there are now other ways to protect the heart besides aspirin, such as cholesterol-lowering medications known as statins, says Dr. Kirtane.

While aspirin advice is changing, other guidance for keeping the heart healthy remains the same: Try to quit smoking, practice portion control, and engage in some aerobic activity four to five times a week for 30 to 45 minutes. In the wake of pandemic-related weight gain, says Dr. Kirtane, “it’s really the time to try to ramp up that exercise.”