New Test Helps Predict Heart Disease Risk

Lp-PLA2 Test Offers Early Warning of Heart Disease Even When Cholesterol Is Low

From the WebMD Archives

Feb. 4, 2004 -- What's your Lp-PLA2? You may not know now. But that may change the next time you see your doctor.

Knowing your risk of heart disease means watching your LDL cholesterol levels. It also may mean keeping track of your C-reactive protein or CRP. And now there's a new addition to the alphabet soup of tests for heart-disease risk: The PLAC test for Lp-PLA2.

If LDL cholesterol is the bad guy, why all the tests? It's because LDL doesn't tell the whole story. A third of people who get heart disease don't have very high LDL levels. That's because LDL becomes more or less harmful in the presence of other factors.

One of these is Lp-PLA2. It's an enzyme -- lipoprotein-associated phospholipase A2 -- that seems to help LDL do its bad thing. There's now a test for Lp-PLA2. And a new study shows that the test may help predict which people with relatively low LDL remain at risk of heart disease.

Christie M. Ballantyne, MD, director of the Center for Cardiovascular Disease Prevention at Baylor College of Medicine, led the study. The findings appear in the Feb. 24 issue of Circulation.

"In the current guidelines, drug therapy is not recommended in primary prevention of coronary heart disease in individuals with LDL cholesterol below 130 mg/dL," Ballantyne says in a news release. "An Lp-PLA2 measurement ... helps identify those who may benefit from risk-reduction interventions such as improved diet, exercise, and drug therapy, before a coronary event occurs."

Low Cholesterol Heart Risk

Ballantyne's team analyzed data from nearly 13,000 apparently healthy, middle-aged men and women. After baseline doctor exams in 1987-1989, the participants underwent three follow-up examinations.

A third of the 608 people who developed heart disease didn't have high LDL cholesterol levels. But they did tend to have high levels of CRP -- C-reactive protein -- and Lp-PLA2. Both CRP and Lp-PLA2 levels independently predicted heart disease.

"The results ... support the rationale that Lp-PLA2 and CRP may be useful to identify patients at increased coronary heart disease risk," Ballantyne and colleagues conclude.

The study was partly funded by diaDexus Inc. of South San Francisco, Calif., which makes the PLAC test for Lp-PLA2.

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SOURCES: Ballantyne, C.M. Circulation, Feb. 24, 2004; vol 109: pp 837-842. News release, diaDexus Inc.
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