C-reactive protein and lesion morphology in patients with acute myocardial infarction

Background-Elevated serum C-reactive protein (CRP) is of clinical significance in the management of acute coronary syndromes, but there have been few in vivo studies detailing the relation between lesion morphology and elevated CRP in the setting of acute myocardial infarction (AMI). In this study, we investigated the relation between lesion morphology as seen under preintervention intravascular ultrasound (IVUS) and CRP in the acute phase of AMI. Methods and Results-Our patient population comprised 90 consecutive patients with AMI who underwent preintervention IVUS within 6 hours of the onset of symptoms. Patients were divided into an elevated CRP group (greater than or equal to 3 mg/L) or a normal CRP group on the basis of serum CRP levels. There were no differences in patient characteristics or angiographic findings. We observed significantly more plaque rupture in the elevated CRP group than in the normal CRP group (70% versus 43%, P=0.01). A multivariate logistic regression model revealed that the presence of ruptured plaque alone correlated with elevation of serum CRP (P=0.02; odds ratio, 3.35; 95% CI, 1.22 to 9.18). Conclusions-Elevated CRP may be related to the presence of ruptured plaque. Our results suggest that in the setting of AMI, elevated CRP levels may reflect the inflammatory activity of a ruptured plaque.