Prospective evaluation of the treatment of intermediate-risk chest pain patients in an emergency department observation unit.

Background: Emergency department observation units (EDOUs) serve an important role in the evaluation and risk stratification of low-risk chest pain patients.

Objectives: Our goal was to evaluate our EDOU protocol for intermediate-risk chest pain patients and compare outcomes and inpatient admission rates for low-risk and intermediate-risk patients.

Methods: Prospective observational study with 30-day telephone follow-up for all chest pain patients admitted to our EDOU from June 1, 2009 to May 31, 2010. Our protocol for intermediate-risk chest pain patients includes patients with a self-reported history of coronary artery disease and negative initial cardiac testing in the emergency department. The EDOU protocol involves telemetry, serial cardiac biomarker testing, and mandatory cardiology consultation.

Results: A total of 552 chest pain patients were evaluated, including 100 (18.1%) intermediate-risk and 452 (81.9%) low-risk patients. Intermediate-risk chest pain patients were significantly more likely to have a myocardial infarction or undergo revascularization (stent or coronary artery bypass graft) (8.0% vs. 2.2%, P = 0.008). Intermediate-risk patients had a higher inpatient admission rate (16.0% vs. 8.8%, P = 0.032). There were no significant unanticipated adverse events at 30-day follow-up in either group.

Conclusions: In conclusion, intermediate-risk chest pain patients in an EDOU had higher rates of significant cardiac events and inpatient admission. Intermediate-risk patients may be appropriate for EDOU placement, given the acceptable inpatient admission rate and the lack of significant adverse events in the 30-day follow-up period. However, given the higher rate of significant cardiac events, the results of our study emphasize the need for increased vigilance and close cardiology consultation in the intermediate-risk group.