Utility of observation units for young Emergency Department chest pain patients

Background: Determining which patients presenting to the Emergency Department (ED) require further work-up for acute coronary syndrome (ACS) can be difficult. The utility of routine observation for cardiac testing in low-risk young adult patients has been questioned. Study Objectives: We investigated the rate of positive findings yielded by routine cardiac observation unit work-up in patients aged 40 years or younger. Methods: This was a retrospective observational cohort study of patients aged 18-40 years who were evaluated for ACS in an ED-based observation unit. Data were collected by trained abstractors from electronic medical records. Results: A total of 362 patients met inclusion criteria. Of those, 239 received stress testing, yielding five positive and nine indeterminate results. One other patient had acute troponin elevation while under observation. The positive stress test patients and troponin-elevated patient underwent cardiac angiography. Only one positive stress test patient showed significant coronary stenosis and received coronary interventions. In follow-up data, one patient had an adverse cardiac outcome within 1 year of index visit, but no coronary interventions. Thus, only 3 patients had adverse cardiac events, with only one patient warranting intervention discovered by observation unit stress testing and a second via serial cardiac markers. Conclusion: Routine observation of symptomatic young adults for ACS had low yield. Observation identified one patient with acute cardiac marker elevation and further stress testing identified only one patient with intervenable ACS, despite a high false-positive rate. This suggests that observation and stress testing should not be routinely performed in this demographic absent other high-risk features.