Purpose: To assess the prognostic value of markers of inflammation for rule-out purposes in patients admitted to the emergency department with troponin T-negative chest pain.
Methods: Patients presenting to the emergency department within 6 hours of symptom onset and who had a normal or nondiagnostic electrocardiogram were eligible. The standard rule-out protocol, which included serial creatine kinase and creatine kinase-MB measurements, was applied, and markers of inflammation (C-reactive protein, erythrocyte sedimentation rate, and total white blood cell count and differential count) were measured. The study group comprised patients with negative serial troponin T results (<0.06 microg/L) who were discharged home after unstable coronary artery disease was ruled out. Endpoints during the 6-month follow-up were cardiac death, myocardial infarction, or rehospitalization for unstable angina.
Results: A total of 382 troponin T-negative patients were discharged, of whom 2 died, 2 had a myocardial infarction, and 7 were rehospitalized for unstable angina. A positive C-reactive protein test result (>0.3 mg/dL) was associated with future clinical events (hazard risk [HR] = 4.5; 95% confidence interval [CI]: 1.2 to 17.0; P = 0.03), as was a positive test (>13 mm/h) for erythrocyte sedimentation rate (HR = 5.6; 95% CI: 1.5 to 22.2; P = 0.01). Patients with positive results for both tests were at highest risk of clinical events (9.3%) compared with patients with other combinations of test results (1.1% to 2.1%; HR = 7.5; 95% CI: 2.2 to 25.5; P = 0.001).
Conclusion: The combination of C-reactive protein and erythrocyte sedimentation rate had prognostic value in patients with troponin T-negative chest pain and a normal or nondiagnostic electrocardiogram in whom unstable coronary artery disease was ruled out.