CHICAGO (Reuters) - A blood test that looks for signs of inflammation in people with high blood pressure does a poor job of predicting who should take statins to lower cholesterol, researchers said on Wednesday.
A large study looking at the use of a high-sensitivity test for measuring C-reactive protein -- a marker for inflammation in the blood -- found it did not add much when researchers considered other factors that raise a person's risk of a heart attack.
"It has a very weak effect in helping to determine who should go on statin treatment," Dr. Donald Lloyd-Jones of Northwestern University told reporters at the American Heart Association meeting in Chicago. Statins include Pfizer Inc 's Lipitor and AstraZeneca's Crestor.
The researchers said their findings suggested the expensive CRP test may not be worth the time or effort.
It followed a study released at the meeting on Tuesday that found a heart scan that checks for hardening of the arteries is better than the CRP test at predicting who might benefit from taking statins.
Statins lower low-density lipoprotein or LDL cholesterol, the "bad" kind, and several studies in recent years have expanded the pool of people who benefit from taking them.
A major heart study two years ago dubbed Jupiter found that giving Crestor, or rosuvastatin, to people with low cholesterol but high levels of C-reactive protein cut in half the risk of heart attacks and strokes.
Some doctors consider rising CRP levels to be a sign of heart attack or stroke risk, while others consider it merely a marker for inflammation.
Lloyd-Jones and colleagues analyzed data on more than 4,800 patients in Britain who had taken part in a study that compared the cholesterol-lowering effects of Lipitor, or atorvastatin, to a placebo.
Patients had been given blood tests at the beginning to check levels of LDL and CRP.
After 5 1/2 years, there were nearly 500 heart attacks and strokes. The team compared those with test results from 1,367 people in the trial who did not have any heart problems.
Measuring both cholesterol and CRP predicted heart attacks and strokes. But when the team also considered other conventional risk factors, such as blood pressure and smoking history, measuring CRP did not add much to the prediction.
Dr. Peter Sever of Imperial College London, who led the study, said the findings were surprising given the results of the Jupiter study.
"The message coming out of the Jupiter study was that we should be screening people for CRP irrespective of their other risk factors," Sever said.
"That's a very, very expensive and almost certainly not a cost effective intervention," he said in a statement, undercutting the Jupiter findings.
Dr. Robert Bonow, former president of the American Heart Association, said CRP "may be helpful, but only to a milder degree."
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