Background: Endothelial function is impaired in patients with coronary artery disease (CAD); in these patients plasma levels of C-reactive protein (CRP) and impaired endothelial function are related to future cardiac events. The aim of the present study was to evaluate the effects of medical therapy on endothelial function and CRP in patients with CAD.
Methods: Seventy-three patients (52 men, 21 women, mean age 66 +/- 9 years) with CAD and 32 control subjects (25 men, 7 women, mean age 65 +/- 11 years) were enrolled in the study. The endothelial function was evaluated by means of flow-mediated dilation (FMD) of the brachial artery following ischemia and CRP by means of a high-sensitivity assay. After baseline evaluation of CRP and FMD all patients received full medical therapy for 3 months and were then again tested for endothelial function and CRP.
Results: Compared to healthy controls, patients had significantly more impaired endothelial function (FMD 3.6 +/- 3.2 vs 8 +/- 2.4%, p < 0.01) and higher CRP plasma levels (1.6 +/- 0.9 vs 0.9 +/- 0.56 mg/dl, p < 0.05). At baseline a significant negative correlation was found between CRP plasma levels and FMD in patients with CAD (r = -0.56, p < 0.05) while no correlation was found in controls. Medical therapy resulted in a significant improvement in endothelial function (3.64 +/- 3 vs 7.2 +/- 3.5%, p < 0.01), and a decrease of CRP (-0.26 +/- 0.19, p < 0.01); the changes in CRP and FMD were independent of the drug used. A positive correlation was found between the improvement in FMD and the degree of CRP reduction (r = 0.57, p < 0.01).
Conclusions: In patients with CAD plasma levels of CRP are associated with an impaired endothelial function suggesting a correlation between inflammation and the integrity of the endothelium. Full medical therapy reduces CRP with a parallel improvement in endothelial function.