Prothrombotic response to coronary angioplasty in patients with unstable angina and raised C-reactive protein

To better understand the mechanisms linking C reactive protein (CRP) to the risk of coronary thrombosis, we investigated the relation between inflammatory state and hemostatic response to coronary angioplasty in patients with either stable or unstable angina.

Plasma levels of von Willebrand factor (vWF) antigen, vWF collagen binding activity, vWF-cleaving-protease, CRP, and whole-blood platelet reactivity were measured before and 24 h after angioplasty in 18 patients with recent unstable angina and in 17 with stable angina. Each group was divided according to preprocedural CRP levels: >or=3 mg/l (in 9 unstable and 9 stable patients) or <3 mg/l (in 9 unstable and 8 stable patients).

Baseline hemostatic parameters did not differ significantly among the four subgroups of patients. After angioplasty, virtually all patients with unstable angina and raised preprocedural CRP showed increased vWF antigen (P = 0.01), vWF collagen-binding (P = 0.001), CRP (P = 0.008), and platelet reactivity (P = 0.0007) compared to baseline, whereas no significant change of these variables was seen within the other three sets of patients. In the overall population, the changes in vWF antigen and vWF-collagen-binding induced by angioplasty correlated with those in CRP levels (r = 0.47, P = 0.004 and r = 0.44, P = 0.008). Baseline levels of vWF cleaving protease and modifications of this enzyme with angioplasty did not differ significantly among subgroups.

Our data suggest that high preprocedural levels of CRP predict a significant vWF rise after angioplasty in patients with unstable angina. The rise in vWF is associated with that in CRP and with enhanced platelet reactivity. Such changes may contribute to the worse prognosis of unstable patients with raised indices of inflammation.