A Message from the Heart
A new test could save the lives of millions who don't even know they're in danger
`So how's your LDL doing?" "It's down--I've been laying off the chips. You?" Who ever would have anticipated that Americans would someday chat casually about their cholesterol? Very soon, another test for heart disease, with at least as much lifesaving value as a cholesterol check, will become equally commonplace. Commit "C-reactive protein" to memory. If you haven't already seen it on a lab printout, you will.
There's nothing new about this protein. It was identified in 1930, and scientists have known for decades that the liver pumps it into the bloodstream when something is going on that results in inflammation. That happens, to cite obvious examples, when you have a cold or a gum infection, or after you cut yourself or have surgery. Or, less obviously, if you are developing cardiovascular problems, because inflammation is now believed by most heart researchers to be the process behind most cardiovascular disease.
Aha, you say. Wouldn't that make CRP a logical indicator for the condition that turns arteries into plaque-filled death traps? That is just what it is turning out to be. An eight-year study of nearly 28,000 women, published in the current issue of the New England Journal of Medicine, found that CRP foretold heart attacks and strokes better than levels of "bad" cholesterol (LDLs, or low-density lipoproteins) did. Combining tests of both cholesterol and CRP, says lead author Paul Ridker, director of the Center for Cardiovascular Disease Prevention at Brigham and Women's Hospital in Boston, would have immense predictive power and enormous impact. "It's high time to move beyond cholesterol," Ridker says firmly.
The study, which is being showcased and debated this week at the American Heart Association's annual science meeting, is the latest and largest of well over 1,000 studies assessing CRP's predictive value. There is a considerable range of opinion. But as the pile has grown, experts have moved steadily toward a consensus that the CRP test could be instrumental in identifying many of the estimated 25 million people who have atherosclerosis but don't know it because by normal standards they're not at high risk. "It will add a new component," says Sidney Smith, the AHA's chief medical officer and head of cardiology at University of North Carolina Hospitals. It doesn't hurt that the test costs only $10 to $25 and has been covered by Medicare since January, although private health insurers generally won't pay for it.
It's not easy to find and treat such individuals, who often don't display the warning flags doctors look for. Half of all heart attacks strike people who don't have a cholesterol problem. Their LDL levels are not high and their levels of protective "good" cholesterol (HDLs, or high-density lipoproteins) are not low. And at least 25 percent of heart attacks happen to individuals with no major risk factors. In addition to having acceptable cholesterol levels, these are people who don't smoke, don't have abnormally high blood pressure, and are not diabetic. Their weight is not always ideal, but they are not obese. Yet somehow the heart disease process has been triggered.
advertisement
