Short-Term Risk of Adverse Cardiac Events Among Emergency Department Patients Placed in an Observation Unit for...

Area of Science:

• Cardiology
• Emergency Medicine
• Clinical Risk Stratification

Background:

• Current practice estimates 6-week risk of major adverse cardiac events (MACE) for acute coronary syndrome (ACS) patients.
• Expedited outpatient programs can reduce costs but require understanding of shorter-term risks.

Purpose of the Study:

• To estimate the 72-hour risk of MACE (72-MACE) in patients admitted to an emergency department observation unit (EDOU).
• To identify patient subgroups with particularly low 72-hour risk profiles.

Main Methods:

• Retrospective cohort study of 1515 EDOU patients (January 2022-June 2023).
• Primary outcome: 72-MACE. Secondary outcomes: other relevant events/treatments.
• Risk estimation across HEART score strata and cumulative incidence curves were generated.

Main Results:

• Overall 72-MACE was 1.4%. Patients with low (0.7%) and intermediate (1.3%) HEART scores had lower risks than high (3.8%) scores.
• Absence of suspicious symptoms and reassuring troponin-T values were associated with significantly lower 72-MACE risk (0.7% in this subgroup).
• MACE events occurred within 56-100 hours in the lowest-risk subgroup.

Conclusions:

• 72-hour MACE risk is low in EDOU patients, especially those with low/intermediate HEART scores.
• A subgroup with favorable symptoms and troponin values demonstrated very low 72-MACE risk.
• Findings support the potential for expedited disposition in select ACS patients.