[Prognostic value of the determination of C-reactive protein in unstable angina]

Why does C-reactive protein increase in non-ST elevation acute coronary syndromes?

INTRODUCTION

C-reactive protein is an important prognostic indicator for early risk stratification in patients with an acute coronary syndrome. The mechanisms underlying the elevation of C-reactive protein in these patients have not been fully understood. We studied the factors related to the increase of this acute-phase reactant.

METHODS AND RESULTS

Within a single-centre registry, 419 consecutive patients admitted for a non-ST elevation acute coronary syndrome were studied. Serum high sensitivity C-reactive protein was measured late (median 3 days) after admission. Clinical, electrocardiographic, biochemical and angiographic variables were recorded. In the multivariate analysis, an increased C-reactive protein (n=162) was related to high levels of troponin I (OR 2.5 (1.6-4) P<0.001) and to a Killip class>1 at presentation (OR 2.9 (1.6-5.4) P<0.001). The coronary angiographic characteristics were not related to C-reactive protein. Finally, in 52 patients with no previous heart disease in whom regional dysfunction was quantified by left ventriculography the presence of a significant (>6 chords) regional dysfunction was significantly related to C-reactive protein (OR 5.1 (1.7-15.3) P=0.006)

CONCLUSION

Our results indicate that in acute coronary syndromes elevated levels of C-reactive protein late after admission are mainly related to clinical, biochemical and angiographic evidences of myocardial damage. The prognostic utility of this parameter could be in part explained by its relationship with a major regional dysfunction.

[Endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin in patients with acute coronary syndrome]

INTRODUCTION AND OBJECTIVES

The acute inflammatory response is an important phenomenon in the pathogenesis of myocardial damage during acute coronary syndrome. Endothelial dysfunction has been found in unstable angina and acute myocardial infarction, although the results are controversial. The purpose of this study was to determine the levels of the soluble endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin, in patients with unstable angina and acute myocardial infarction, compare the results in both groups, and analyze their relation with the degree of myocardial injury.

METHODS

Serum concentrations of ICAM-1, VCAM-1, and E-selectin were measured in 37 control subjects and 43 patients (32 with acute myocardial infarction and 11 with unstable angina). Measurements were made at the time of admission and ten days later using commercial enzyme-linked immunoabsorbent assay (ELISA) kits (R&D Systems, UK).

RESULTS

There was a significant increase in E-selectin (p < 0.05) in patients with unstable angina at admission and ten days later. In contrast, patients with acute myocardial infarction showed no significant differences in E-selectin compared with the control group at admission or ten days later. A significant increase in VCAM-1 levels was demonstrated in both groups of patients and ICAM-1 levels in acute myocardial infarction, but the concentrations of VCAM-1 and ICAM-1 in both groups of patients at admission and ten days later did not differ significantly. There was no relation between soluble endothelial adhesion molecule levels and the severity of myocardial damage estimated by cardiac enzymes or electrocardiographic changes.

CONCLUSION

This study indicates that serum levels of E-selectin, measured at time of admission and ten days later, could be a marker for unstable angina and might be useful in the differential diagnosis with myocardial infarction.

[Eptifibatide blocks the increase in C-reactive protein concentration after coronary angioplasty]

We measured C-reactive protein concentrations in 31 patients with interventional procedures after blocking thrombosis in 17 of them by the administration of a 12 hour long infusion of eptifibatide in order to evaluate the role of arterial thrombosis. There were no differences in C reactive protein concentration between the treated and control group pre-angioplasty (0.32 0.4 vs 0.56 0.57 md/dl; p = NS), nor post-angioplasty (0.35 0.42 vs 0.53 0.5 mg/dl, p = Ns). The eptifibatide group maintained basal C reactive protein concentrations 6 hours after the procedure, while the control group had a significant increase (0.43 0.5 vs 1.02 0.89 mg/dl; p < 0.05). There was a decrease in C reactive protein 24 hours after angioplasty in eptifibatide group (0.24 0.27 vs 1.34 0.89 mg/dl; p < 0.001), but it increased again 48 hours after the procedure although to a lesser extent than in the control group (0.57 0.55 vs 2.18 2.1 mg/dl; p < 0.05). Eptifibatide, a synthetic peptide which is a selective blocker of the platelet GP IIb/IIIa receptor significantly reduced C-reactive protein concentration after angioplasty.