New blood test may improve risk assessment for ischemic stroke in middle aged adults

November 28, 2005

diaDexus, Inc. and the Methodist DeBakey Heart Center today announced the publication of a landmark study in the American Medical Association's Archives of Internal Medicine demonstrating a greater than 11-fold increased risk of ischemic stroke in individuals with high levels of both lipoprotein-associated phospholipase A2 (Lp-PLA2), an enzyme related to arterial plaque formation, and C-reactive protein (CRP), a marker of general inflammation.1

"Although a number of medications are known to reduce the incidence of stroke, national screening guidelines for cholesterol are based only on the risk for developing heart disease and do not include stroke," said Christie Ballantyne, MD, director of the Center for Cardiovascular Disease Prevention at the Methodist DeBakey Heart Center and Baylor College of Medicine in Houston, and lead author of the study. "The lack of association between lipid levels and future ischemic stroke has made identifying patients at risk for stroke a challenge to the medical community. Our findings suggest that a panel of Lp-PLA2 and CRP may help identify those high risk individuals, so that proactive measures can be taken to lower those risks and avoid a stroke."

Study Details
The NHLBI's Atherosclerosis Risk in Communities (ARIC) study followed 12,762 apparently healthy bi-racial middle-aged men and women for six to eight years to evaluate incidence of major cardiovascular events. The case-cohort analysis, evaluating the relationship of Lp-PLA2 and CRP levels to ischemic stroke, was coordinated by Dr. Ballantyne at the Methodist DeBakey Heart Center and also involved researchers from the University of North Carolina at Chapel Hill, Johns Hopkins School of Public Health, University of Minnesota, The National Institutes of Health and University of Texas.

Lp-PLA2 levels were assessed using the diaDexus PLAC® test, the first blood test approved by the FDA to aid in predicting ischemic stroke associated with atherosclerosis. CRP was measured using an assay from Denka Seiken.

Using a Cox proportional hazards model, the study demonstrated that Lp-PLA2 was independently associated with ischemic stroke after adjusting for age, sex, race and confounders including LDL-cholesterol, HDL-cholesterol, diabetes, smoking, hs-CRP levels and blood pressure. Additionally, the effect of Lp-PLA2 in combination with CRP was highly significant. Individuals with the highest levels of both Lp-PLA2 and CRP had an 11.38-fold (95% CI 3.13-41.41) increased risk of suffering an ischemic stroke during the study, compared to individuals with the lowest levels of Lp-PLA2 and CRP. Notably, LDL-cholesterol levels did not differ between incident stroke cases and non-cases and, in fully adjusted models, LDL-cholesterol, HDL-cholesterol and triglycerides were not associated with increased risk for stroke consistent with previous reports. 2

"Stroke is the third largest killer in the United States. The PLAC test will help improve identification of the high risk patients, allowing physicians to implement basic prevention strategies and potentially reduce the number of strokes that occur each year," said Richard B. Lanman, MD, Executive Vice President and Chief Medical Officer of diaDexus. "Additional analyses have shown that Lp-PLA2 has the unique capability of predicting future ischemic stroke and in combination with more traditional risk factors, particularly blood pressure measurements, it allows physicians to identify those stroke prone hypertensive patients who may benefit from more aggressive treatment programs."

Stroke is a leading cause of serious long-term disability. Each year approximately 700,000 strokes occur, 88% of which are ischemic strokes. While elevated cholesterol levels are directly linked to heart disease, no such relationship has been established for stroke.
This study was supported by the National Institutes of Health (NIH) and an unrestricted grant from GlaxoSmithKline.

About diaDexus
diaDexus, Inc., a privately held biotechnology company based in South San Francisco, California, is focused on the discovery, development and commercialization of novel, patent-protected diagnostic and therapeutic products with high clinical value. The PLAC® test, developed by diaDexus, Inc., is a blood test cleared by the U.S. Food and Drug Administration to aid in the prediction of an individual's risk for a coronary or ischemic stroke event, in conjunction with clinical evaluation and patient risk assessment. For more information about the PLAC® test visit More information about the company may be found at

About the Methodist DeBakey Heart Center
The Methodist DeBakey Heart Center is a world-renowned organization that is consistently ranked among the top heart centers in the nation. Located in Houston, Texas, the Methodist DeBakey Heart Center combines research, prevention, diagnostic care, surgery and rehabilitation services in a coordinated multi-disciplinary program with one focus: delivering compassionate, effective care and treatment to patients with heart disease. For more information about the Methodist DeBakey Heart Center, visit

1. Ballantyne C, Hoogeveeen R, Bang H, et al. Lipoprotein-associated phospholipase A2, high-sensitivity C-Reactive Protein, and Risk for Incident Ischemic Stroke in Middle-aged Men and Women in the Atherosclerosis Risk in Communities (ARIC) Study. Arch Intern Med. 2005; 165:1-7.

2. Shahar E, Chambless LE, Rosamond WD, et al. Plasma lipid profile and incident ischemic stroke: the Atherosclerosis Risk in Communities (ARIC) study. Stroke. 2003; 34:623-631.

Edelman Public Relations

Related Heart Disease Articles from Brightsurf:

Cellular pathway of genetic heart disease similar to neurodegenerative disease
Research on a genetic heart disease has uncovered a new and unexpected mechanism for heart failure.

Mechanism linking gum disease to heart disease, other inflammatory conditions discovered
The link between periodontal (gum) disease and other inflammatory conditions such as heart disease and diabetes has long been established, but the mechanism behind that association has, until now, remained a mystery.

New 'atlas' of human heart cells first step toward precision treatments for heart disease
Scientists have for the first time documented all of the different cell types and genes expressed in the healthy human heart, in research published in the journal Nature.

With a heavy heart: How men and women develop heart disease differently
A new study by researchers from McGill University has uncovered that minerals causing aortic heart valve blockage in men and women are different, a discovery that could change how heart disease is diagnosed and treated.

Heart-healthy diets are naturally low in dietary cholesterol and can help to reduce the risk of heart disease and stroke
Eating a heart-healthy dietary pattern rich in vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, vegetable oils and nuts, which is also limits salt, red and processed meats, refined-carbohydrates and added sugars, is relatively low in dietary cholesterol and supports healthy levels of artery-clogging LDL cholesterol.

Pacemakers can improve heart function in patients with chemotherapy-induced heart disease
Research has shown that treating chemotherapy-induced cardiomyopathy with commercially available cardiac resynchronization therapy (CRT) delivered through a surgically implanted defibrillator or pacemaker can significantly improve patient outcomes.

Arsenic in drinking water may change heart structure raising risk of heart disease
Drinking water that is contaminated with arsenic may lead to thickening of the heart's main pumping chamber in young adults, according to a new study by researchers at Columbia University Mailman School of Public Health.

New health calculator can help predict heart disease risk, estimate heart age
A new online health calculator can help people determine their risk of heart disease, as well as their heart age, accounting for sociodemographic factors such as ethnicity, sense of belonging and education, as well as health status and lifestyle behaviors.

Wide variation in rate of death between VA hospitals for patients with heart disease, heart failure
Death rates for veterans with ischemic heart disease and chronic heart failure varied widely across the Veterans Affairs (VA) health care system from 2010 to 2014, which could suggest differences in the quality of cardiovascular health care provided by VA medical centers.

Heart failure: The Alzheimer's disease of the heart?
Similar to how protein clumps build up in the brain in people with some neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, protein clumps appear to accumulate in the diseased hearts of mice and people with heart failure, according to a team led by Johns Hopkins University researchers.

Read More: Heart Disease News and Heart Disease Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to