[C-reactive protein as an independent marker of prognosis in acute coronary syndrome: comparison with troponin T].

Background: It has been suggested that inflammatory processes play a role in the pathogenesis of acute coronary syndromes (ACS). C-reactive protein (CRP) is a classic acute phase protein. It is yet unclear whether, in addition to established markers as troponin T (TnT), determination of CRP in patients admitted for ACS contributes significantly to the diagnosis and prognosis of ACS.
Patients and Methods: We investigated 50 patients with ACS (59.4 SD 13.9 years) in the first hour after admission and 4-24 h later with respect to TnT (Elecsys, Roche Diagnostics) and CRP (biokit, modified Quantex CRP plus, analytical sensitivity 0.02 mg/dL). Fifty percent of the patients were classified as having unstable angina retrospectively. All patients were followed in the 6 weeks post discharge regarding death and recurrent ACS.
Results: The cumulative event rate at 6 weeks after discharge was 62.5% for patients being CRP and TnT positive compared to 35.3% in TnT positive and CRP negative patients. In TnT negative patients a positive CRP test predicted 33.3% of events and 28.8% of patients negative for CRP and TnT had events at 42 days post discharge. Logistic regression analysis regarding the primary endpoint including TnT and CRP (4-24 h values), age, gender and diagnosis resulted in independent prediction of ACS or death by TnT (cutoff 0.1 microgram/L, p = 0.048, odds ratio = 7.5) and CRP (cutoff 0.862 mg/dL, p = 0.026, odds ratio = 5.3). Sensitivity/specificity for AMI diagnosis were 69.6%/75% for TnT and 12%/72% for CRP in the first hour and 91.3%/68.2% for TnT and 68%/72% for CRP 4-24 h later.
Conclusions: Besides TnT, high sensitivity CRP determination has no additional value for early AMI diagnosis. The prognosis of these patients during the first 24 hours is significantly and independently predicted by CRP measurements in addition to troponin T.