Why does C-reactive protein increase in non-ST elevation acute coronary syndromes?: Role of myocardial damage

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.