The prognostic value of markers of inflammation in patients with troponin T–negative chest pain before discharge from the emergency department

Abstract

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 μg/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.