Determining The Benefits Of Aspirin

By Jane Farrell

Scientists have developed a method for figuring out who should take aspirin to prevent heart attacks. Although the remedy has been recommended for more than 30 years, it’s been unclear exactly which individuals might benefit.

New research published today in Circulation: Cardiovascular Quality and Outcomes shows that coronary artery calcium (CAC) score, a measurement of plaque in arteries that feed the heart, could help determine whether a person should take aspirin.

 “Many heart attacks and strokes occur in individuals who do not appear to be at high risk,” said lead author, Michael D Miedema, MD, MPH, a clinical investigator at the Minneapolis Heart Institute Foundation. “Individuals with known CVD [cardiovascular disease] should take a daily aspirin, but the best approach for individuals without known CVD is unclear. If we only treat high-risk individuals with aspirin, we are going to miss a substantial portion of patients who eventually suffer heart attacks. However, liberally prescribing aspirin increases the bleeding risk for a significant number of people who were never going to have a heart attack in the first place. With this study, we wanted to see if there is potentially a better way to determine who to treat with aspirin beyond simply using traditional risk factors.”

The American Heart Association (AHA) guidelines currently recommend aspirin to prevent cardiovascular disease (CVD) in people who have known CVD or who are considered at high risk for a CVD event. Aspirin is generally not recommended for people who are considered to be at low or intermediate risk.

For the study, researchers looked at 4,229 participants in the the Multi-Ethnic Study of Atherosclerosis (MESA) from six centers across the country. Participants included had no known CVD or diabetes, were not on aspirin therapy, and were followed for approximately 7 years.

Participants were grouped according to their CAC score, and the investigators found that those with elevated CAC scores were two to four times likelier to benefit from aspirin therapy. On the other hand, patients with a low CAC score were likelier to be harmed by aspirin use.

Approximately 50% of middle-aged men and women have a CAC score of zero.