Heart Disease Health Center

New Test Best Measure of Heart Risk

Feb. 27, 2003 -- Cholesterol, schmolesterol. The name of the heart disease game is now ApoB, researchers are telling doctors.

It's not that cholesterol isn't important. After all, more scientists have won Nobel Prizes from studying cholesterol than any other molecule. But science has marched on. Four huge clinical trials now show that there's a better single measure of heart-disease risk than cholesterol levels. It's called apolipoprotein or Apo for short.

Apolipoproteins are tiny fat particles floating in the blood. Having a lot of one kind of Apo -- apolipoprotein B or ApoB -- means high risk of clogged arteries and heart attack. A high ApoB count predicts heart disease even better than a high level of "bad" LDL cholesterol, argue Allan Sniderman, MD, and colleagues. This international group of experts also argues that the ratio of ApoB to ApoA1 (another kind of Apo) tells doctors more than the ratio of LDL cholesterol to "good" HDL cholesterol.

"The measurement of apolipoproteins should now be introduced broadly into clinical practice," Sniderman and colleagues write in the March 1 issue of The Lancet.

The experts based their opinion on several huge clinical trials.

The new test should be particularly helpful for patients taking cholesterol-lowering drugs. Many studies show that LDL cholesterol levels don't do a good job of predicting heart disease risk in these patients. For them, measuring ApoB and the ApoB/ApoA1 ratio may be better.

Good tests for Apo already exist. In fact, they are even easier than cholesterol tests. That's because a patient doesn't have to fast before giving a blood sample. So why aren't most doctors already using the tests?

"The importance of cholesterol is densely entrenched within the medical profession and lay public," Sniderman and colleagues note. "The pace of change will be determined, in part at least, by how resistant conventional belief is to emerging clinical evidence."

SOURCE: The Lancet, March 1, 2003.