Hunt for Heart Disease Tracks a New Suspect

C-reactive protein, or CRP, a natural chemical produced in the liver and released into the bloodstream in the presence of acute or chronic inflammation is a big marker for sudden cardiac deaths.

In the continuing Physicians' Health Study of 22,000 men, 97 apparently healthy participants suffered sudden cardiac deaths. The only factors predictive of their fates over 17 years of study were elevated C-reactive protein levels, Dr. Christine M. Albert of Brigham and Women's Hospital and her Boston colleagues reported in May 2002 in the journal Circulation.

In women, too, the C-reactive protein appears to be a better predictor of heart attack, stroke and other signs of cardiovascular disease than the so-called bad cholesterol, low density lipoprotein, or L.D.L.

In a study of 28,000 apparently healthy American women followed for an average of eight years, levels of C-reactive protein were directly related to the development of cardiovascular events like heart attacks and strokes and more strongly predicted such problems than levels of L.D.L. cholesterol, Dr. Paul M. Ridker and colleagues at Brigham and Women's Hospital reported in November 2002 in The New England Journal of Medicine.

The role of C-reactive protein as a contributor to cardiovascular disease fits nicely into the understanding that inflammation is central to every stage of atherosclerotic disease, from the start of plaque formation in arteries to the rupture of those plaques, which can precipitate a heart attack or stroke.

Basic research has shown, for example, that CRP can enhance destruction of arterial lining cells, activate adhesion molecules and blood clotting factors and interfere with substances that increase circulation to the heart.

Furthermore, a new study by heart and kidney specialists in South Korea suggests that C-reactive protein is "an independent risk factor for the development of hypertension," which in turn increases the chances of suffering a heart attack or stroke.