Quantitative CRP Value in Assessing Myocardial Infarction of Unstable Angina Patients

Introduction: Several studies have shown the independent association of high plasma
C-reactive protein (CRP) levels with adverse prognosis in patients with acute myocardial infarction (MI). The aim of this study was to assess the prognostic value of quantitative CRP (Q-CRP) to predict MI in patients with unstable angina.

Materials & Methods: This cohort study was carried out between December 2003 & June 2004 in Tehran Heart Centre. 121 patients with unstable angina were selected. Q-CRP of these patients was measured and10 mg/L considered as a cut-off point value for Q-CRP. Patients divided into two groups according to their Q-CRP cut-off value. Group A with Q-CRP≥10 mg/L (n= 68) and group B with Q-CRP<10 mg/L (n= 53). All patients were monitored for development of MI during the period of hospitalisation. The results were analysed to find out predictive value of Q-CRP in MI prognosis.

Results: The mean age of patients was 60±7 year, 72 (59.5%) male and 49 (40.5%) female.  Mean CRP value of participants was 14.42±7/3 (4-60 mg/L). MI was developed in four (5.8 %) patients in group A and in one (1.8 %) patient in group B. There was no significant correlation between Q-CRP level and MI development (P>0.38). The sensitivity, specificity, positive and negative predictive values of Q-CRP in this study was 98.3%, 58.5%, 80% and 19.5% respectively.

Conclusion: Although there was no significant correlation between Q-CRP level and MI development, in area with limited facilities, Q-CRP can be used for categorization of subjects with high and low risk of MI in unstable angina patients.