Evaluation of C-reactive protein, a sensitive marker of inflammation, as a risk factor for stable coronary artery disease.

OBJECTIVES: Multiple lines of investigations have converged to suggest a prominent role for inflammation in coronary artery disease (CAD). The association of CRP level with active CAD is well documented. The relation, however, between levels of CRP and the presence and extent of stable CAD has seldom been studied in the developing countries. We investigated the association between serum concentration of C-reactive protein (CRP) and angiographically documented coronary artery disease (CAD) in a population of 450 individuals. DESIGN AND METHODS: Ultrasensitive immunoassay was used to measure CRP levels in 284 patients with CAD and 166 control healthy subjects. The association of CRP levels with severity of disease as indicated by > or = 50% stenosis in one vessel (n = 79), two vessels (n = 74), or three vessels (n = 131) was also investigated.
RESULTS: CRP levels were greater in the patients with CAD (2.14 (0.88--3.38) vs. 1.45 (0.70--2.55) mg/L, p < 0.0001) than in the respective control subjects. Multiple logistic regression analysis showed CRP as an independent discriminating risk factor for CAD (odds ratio, 3.46, p < 0.001). Significant correlation was identified between CRP levels and severity of CAD (p < 0.0001). Prediction models that incorporated CRP in addition to other established coronary risk factors were significantly better at predicting risk than the models based on the other risk factors alone. CRP level was also an independent predictor of CAD in a subpopulation with normal levels of low density lipoprotein cholesterol (LDL-C < or = 3.4 mmol/L, p < 0.009).
CONCLUSIONS: Our findings suggest that CRP has a strong association with stable CAD, as such, the measurement of CRP may improve the coronary risk assessment in Iranian CAD patients.