Aspirin Use for Heart Disease Prevention May Benefit Those with Coronary Artery Calcium Deposits

A recent study found that taking aspirin to prevent heart disease benefits individuals with high coronary artery calcium (CAC) scores but can actually cause damage from bleeding in individuals with low levels of coronary artery calcium.

An individual's CAC score is determined by using computerized tomography (CT) to scan the coronary blood vessels. Calcium deposits show up as bright white spots on the scan.

Investigators at the Minneapolis Heart Institute (MN, USA) monitored 4,229 individuals participating in the Multi-Ethnic Study of Atherosclerosis (MESA) at six centers in the USA. Participants had no known CVD (cardiovascular disease) or diabetes, were not on aspirin therapy, and were followed for approximately seven years.

Results revealed that participants with elevated CAC scores (greater than 100) were two to four times more likely to benefit from aspirin therapy than to be harmed, even if they did not qualify for aspirin use according to current American Heart Association guidelines. Conversely, MESA participants with no calcified plaque (CAC score = zero) were two to four times more likely to be harmed by aspirin use than to benefit.

“We estimate that individuals with significant plaque buildup in the arteries of the heart are much more likely to prevent a heart attack with aspirin use than to suffer a significant bleed,” said first author Dr. Michael D. Miedema, a preventative cardiologist at the Minneapolis Heart Institute. “On the opposite end of the spectrum, if you do not have any calcified plaque, our estimations indicate that use of aspirin would result in more harm than good, even if you have risk factors for heart disease such as high cholesterol or a family history of the disease.”

“A CAC score of zero is associated with a very low risk of having a heart attack. That means individuals with a score of zero may not benefit from preventive medications, such as aspirin as well as the cholesterol-lowering statin medications. Approximately 50% of middle-aged men and women have a CAC score of zero, so there is a potential for this test to personalize the approach to prevention and allow a significant number of patients to avoid preventive medications, but we need further research to verify that routine use of this test is the best option for our patients.”

The study was published in the May 6, 2014, online edition of the journal Circulation: Cardiovascular Quality and Outcomes.

Related Links:
Minneapolis Heart Institute