Origin of Clinically Significant Acute Phase Reaction in Acute Coronary Syndromes: Myocardial Necrosis or Plaque Rupture?

Purpose: This study was aimed to investigate the hypothesis that clinically significant C-reactive protein releases in acute coronary syndromes (ACS) occur secondary to myocardial necrosis in response to interleukin-6. Materials and Methods: This prospective randomized clinical study was conducted between March 2005 and May 2005 in an emergency department of a tertiary care hospital. Patients with typical chest pain were enrolled into the study. Initial cardiac Troponin-T, interleukin-6 (IL-6) and high sensitive CRP (hsCRP) levels were measured. IL-6 and hsCRP levels were compared between patients with or without myocardial infarction. Results: A total of 132 patients were enrolled to the study. Finally 15 (11.5%) patients were diagnosed as stable angina pectoris, 60 (46.2%) were unstable angina pectoris, 18 (13.8%) were non-ST segment elevation MI and 37 (28.5%) patients were ST segment elevation MI. hsCRP levels (81.8% vs 59.1 %, p=0.047) and IL-6 (54.5% vs 30.1%, respectively; p=0.03) levels were significantly higher in patients with myocardial necrosis. A moderate correlation was also found between the levels of hsCRP and IL-6 (r=0.556). Conclusion: High sensitivity CRP levels can increase both in plaque rupture and myocardial necrosis. ACS is associated with greater inflammation in the presence of myocardial necrosis than in cases of angina without necrosis.