Gamma-prime fibrinogen could help determine CAD risk
MedWire News: A test for plasma γ’ fibrinogen levels can identify patients at risk for coronary artery disease (CAD), a study indicates.
“We found that that if your γ’ fibrinogen levels were in the top 25%, you had seven times greater odds of having CAD,” explained lead author David Farrell (Oregon Health and Science University, Portland, USA).
Farrell highlighted that testing for γ’ fibrinogen levels may be particularly helpful in identifying people with normal cholesterol levels who are nevertheless at risk for CAD.
In the study, Farrell and team determined the reference interval for γ’ fibrinogen in plasma samples from 2879 individuals without cardiovascular disease from the seventh cycle of the Framingham Offspring Study.
Levels of γ’ fibrinogen varied nearly 40-fold, ranging from 0.037 g/l to 1.443 g/l. The reference interval, defined by the 2.5th and 97.5th percentile limits, was 0.088–0.551 g/l and the median concentration was 0.234 g/l.
Analysis showed that γ’ fibrinogen levels were significantly associated with age, gender, body mass index, smoking, diabetes, blood glucose, and triglycerides (all p<0.05).
The researchers then investigated the ability of γ’ fibrinogen to discriminate between individuals with and without CAD, by comparing levels in a cohort of 133 CAD patients aged a mean of 62 years with those in the Framingham cohort, who were of similar age.
They found that γ’ fibrinogen levels were significantly higher in CAD patients than controls, at 0.413 g/l versus 0.299 g/l (p<0.001).
Receiver operating characteristic curve analysis indicated that a γ’ fibrinogen concentration of around 0.30 g/l was optimal for detecting CAD, with diagnostic accuracy of 0.78 at this threshold for discriminating between patients with and without CAD.
“It will take some time to build consensus within the field of cardiology for this test,” commented Farrell. “The γ’ fibrinogen test would be used in conjunction with a cholesterol test to better predict who is likely to suffer a heart attack. Ultimately we are optimistic we can identify people who are at risk who didn’t know they are at risk.”
The study appears in the journal Clinical Chemistry.
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By Caroline Price