Evaluation of C-reactive protein, fibrinogen and antithrombin-III as risk factors for coronary artery disease

Background: Inflammation is an important feature of atherosclerotic lesions and increased production of the acute-phase reactant. The contribution of coagulation factor to the development of coronary artery disease has not yet been clearly established. Objectives: To test whether C-reactive protein, fibrinogen and antithrombin-III are associated with angiographic CAD, history of myocardial infarction and extensive atherosclerotic involvement. Methods: Blood samples were tested for CRP, fibrinogen and AT-III levels from 219 individuals undergoing coronary angiography. Results: CRP was higher in patients with CAD (0.95±1.31, n=180, vs. 0.39±0.61 mg/dl, n=39, P<0.0001) and in those with a history of MI (1.07±1.64, n=96, vs. 0.65±0.72 mg/dl, n=84, P<0.05) than in control subjects. The patients who developed unstable angina had higher CRP levels than the patients with stable CAD (2.07±2.38, n=7, vs. 0.80±1.13 mg/dl, n=173, P<0.001). Fibrinogen was significantly higher in patients with CAD than in those without CAD (298±108 vs. 258±63 mg/dl, P<0.01). In patients with CAD, mean AT-III value was less than in patients without CAD, but this difference was not statistically significant (P=0.08). No difference was found in CRP, fibrinogen and AT-III values among the patients with single, double or triple vessel disease. Conclusions: CRP is elevated in patients with CAD and a history of MI. Elevated levels of CRP at the time of hospital admission is a predictive value for future ischemic events. There is an association between higher levels of fibrinogen and CAD. The association of AT-III levels with CAD needs testing in further studies.