Blood Test May Help Predict Ischemic Stroke Risk

January 12, 2009
Todd Kunkler

Researchers have found that "testing patient's blood for two proteins or biomarkers that occur when inflammation is present could help doctors identify which patients are more likely to have a stroke."

According to a Baylor College of Medicine (BCM) news release, researchers led by Dr. Vijay Nambi, assistant professor of medicine-atherosclerosis and vascular medicine at BCM and staff cardiologist Center for Cardiovascular Disease Prevention at The Methodist DeBakey Heart and Vascular Center, have found that “testing patient's blood for two proteins or biomarkers that occur when inflammation is present could help doctors identify which patients are more likely to have a stroke.”

When investigators studied blood test results for 949 people taking part in the Atherosclerosis Risk in Communities study, they discovered they could obtain a better picture of the risk of stroke for each patient by testing for the biomarkers lipoprotein-associated phospholipase A2 (Lp-PLA2) and high-sensitivity C-reactive protein (hs-CRP), which are “known to be associated with an increased risk of the kind of stroke that occurs when blood flow to the brain is blocked.”

Using conventional risk factors (including age, sex, race, whether a person smokes, blood pressure, diabetes, use of high blood pressure medication and body mass index as a measure of obesity) to determine participants’ likelihood of suffering an ischemic stroke, the researchers defined patients with a less than 2% chance of ischemic stroke in the next five years as “low risk.” Patients with a 2-5% chance were defined as “intermediate risk,” and patients with greater than a 5% chance were defined as “high risk.”

When Nambi and his team incorporated the results of the blood tests for the two biomarkers, they found that many patients moved from one risk category to another. They reported that 4% of people at low risk moved to intermediate risk, and 11% moved from intermediate moved to high risk. They also found that some patients risk decreased, with 33% at high risk moving down to the ‘intermediate risk” category.

Nambi said that “Adding each biomarker individually to the traditional risk factors for ischemic stroke improved prediction. However, adding both, along with taking into account how the two interact, gave the most improvement in prediction.”

“While more studies must be done to determine if these categories can be used as a standard, these results show us one strategy to classify an individual's stroke risk and how this can be altered by the addition of novel blood tests,” Nambi said. “By adding the two biomarkers we can better identify those at higher risk for stroke. Future studies should determine if changing treatment options based on risk could improve the prevention of ischemic stroke.”

The complete results of the study were published in the journal Stroke; click here to read the abstract.