Aspirin therapy or taking a daily aspirin are recommended by the doctor to those who had heart attack or stroke or once identified at risk, however, a new study suggests that the effectiveness of this treatment depends on the genes of the patient.

Deepak Voora, lead author of the study and a professor of Duke University, and his colleagues initiated the study to identify the relationship of the Aspirin Response Signature (ARS)—a collection of 60 co-expressed genes- on the possible response of the body to aspirin therapy and the risk of the patients to heart attack or stroke. They wanted to prove that these biomarkers can tell if the patient really needs aspirin or not.

The researchers divided the participants into two groups: healthy patients consuming 325 mg of aspirin per day for prevention and patients who had heart attack or stroke consuming 81 mg of aspirin per day. The second group also had cardiac catheterization to treat their condition.

The participants had to undergo blood test in order for the researchers to check their platelet function or its ability to prevent blood clotting which is often the cause of heart attack and stroke. They also wanted to see the presence of the Aspirin Response Signature (ARS) on each patient.

The researchers found out that the body’s reaction to aspirin therapy varies wherein 30 percent of the second group is still at risk to another episode of heart attack or stroke. To put it simply, the aspirin therapy didn’t work for them because they don’t have the ARS. The team will do further research on the patients found to have ARS to further establish their conclusion.

"The main finding of our study is that we've developed a whole blood-based biomarker that physicians could potentially use as a diagnostic test to identify those who are adequately responding to aspirin or not, and also to identify those individuals who are at highest risk for MI and death in patients who are taking aspirin," Voora wrote in the report.

The study was published on the July 3 issue of the Journal of the American College of Cardiology.