A study investigates which people are most at risk of premature death due to cardiovascular disease after having a heart attack. One biomarker may help healthcare providers to personalize their predictions.

Acute coronary syndrome (ACS) describes a range of cardiovascular conditions that are characterized by a sudden and dangerous reduction of blood flow to the heart.

ACS can also, in some cases, lead to a major heart attack.

So far, the known risk factors for ACS include age (it is most common in people over 65), gender (with men being more at risk than women), and medical history (with diabetes, hypertension, and high cholesterol being the main culprits).

Recently, researchers from the University of Sheffield in the United Kingdom set out to investigate whether or not there are any biomarkers that could predict an elevated risk of ACS in people who have already been through a heart attack.

Lead researcher Prof. Robert Storey—from the university's Department of Infection, Immunity and Cardiovascular Disease—and his team noticed that blood plasma might provide practitioners with the clue they need to detect the possibility of cardiovascular disease.

Their findings were published in the European Heart Journal.

Stubborn clots tied to higher risk

Prof. Storey and colleagues analyzed data from 4,354 participants in the PLATelet inhibition and patient Outcomes trial to "evaluate the safety and efficacy of treatment" with two different blood-thinning drugs used to prevent the formation of blood clots.

The participants all had a form of ACS and had been admitted to hospital for a heart attack.

For the purpose of the new study, blood samples were collected from these participants upon their discharge from hospital. Next, the scientists analyzed the blood plasma—or the yellowish liquid that holds blood cells together—to see if it could provide any indication as to what might put people at increased risk of ACS.

The researchers focused on two biomarkers:

• "maximum turbidity," or the maximum density of a blood plasma clot, which is known as a "fibrin clot" after the plasma protein that keeps it together
• "clot lysis time," or the time that it takes for a clot to dissolve

"We [...] aimed to study fibrin clot properties in plasma samples collected from ACS patients at hospital discharge and explore the relationship between those characteristics and subsequent clinical outcomes," the researchers write.

First, Prof. Storey and team adjusted for known ACS risk factors, so as to ensure the solidity of the study's findings.

After these adjustments, the researchers concluded that the participants for whom it took the longest to dissolve a clot had a 40% higher risk of experiencing another heart attack or dying prematurely due to cardiovascular disease.

"We have made huge strides over the last two decades in improving prognosis following heart attacks but there is still plenty of room for further improvement," notes Prof. Storey.

He continues, "Our findings provide exciting clues as to why some patients are at higher risk after heart attack and how we might address this with new treatments in the future."

The team explains that the current findings indicate that drugs that will help blood clots dissolve faster in people with a naturally long clot lysis time could improve the health outcomes for those already living with ACS.

"We now need to press ahead with exploring possibilities for tailoring treatment to an individual's risk following a heart attack and testing whether drugs that improve clot lysis time can reduce this risk."

Prof. Robert Storey