Utility of routine coagulation studies in emergency department patients with suspected acute coronary syndromes.

BACKGROUND: Many emergency departments use coagulation studies in the evaluation of patients with suspected acute coronary syndromes.
OBJECTIVES: To determine the prevalence of abnormal coagulation studies in ED patients evaluated for suspected ACS, and to investigate whether abnormal international normalized ratio/partial thromboplastin time testing resulted in changes in patient management and whether abnormal results could be predicted by history and physical examination.
METHODS: In this retrospective observational study, hospital and ED records were obtained for all patients with a diagnosis of ACS seen in the ED during a 3 month period. ED records were reviewed to identify patients in whom the cardiac laboratory panel was performed. Other data included demographics, diagnosis and disposition, historical risk factors for abnormalities of coagulation, ED and inpatient management, INR/PTT, platelet count and cardiac enzymes. Descriptive statistical analyses were performed.
RESULTS: Complete data were available for 223 of the 227 patients (98.7%). Of these, 175 (78.5%) were admitted. The mean age was 64.2 years. Thirteen patients (5.8%) were diagnosed with acute myocardial infarction. Of the 223 patients, 29 (13%) and 23 (10%) had INR and PTT results respectively beyond the reference range. Seventy percent of patients with abnormal coagulation test results had risk factors for coagulation disorders. The abnormal results of the remaining patients included only a mild elevation and therefore no change in management was initiated.
CONCLUSIONS: Abnormal coagulation test results in patients presenting with suspected ACS are rare, they can usually be predicted by history, and they rarely affect management. Routine coagulation studies are not indicated in these patients.