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The following is a summary of “Short-Term Risk of Adverse Cardiac Events Among Emergency Department Patients Placed in an Observation Unit for Cardiac Testing,” published in the February 2025 issue of Journal of Emergency Medicine by Reynolds et al. 

Estimating the 6-week risk of major adverse cardiac events (MACE) guided emergency department (ED) disposition for individuals with suspected acute coronary syndrome and reassuring evaluation.  

Researchers conducted a retrospective study to estimate the 72-hour risk of MACE (72-MACE) and other outcomes among individuals admitted to an observation unit (EDOU) for cardiac testing.  

They analyzed data from individuals admitted to the EDOU from 01/01/22 to 06/30/23. The primary outcome was the 72-MACE, while secondary outcomes included treatments and events not classified under MACE and the outcome of risks across HEART score strata were estimated, also explored modeling approaches to identify subgroups with minimal risk and generated cumulative incidence curves for all outcomes.  

The results showed that among 1,515 individuals, 85% had intermediate HEART scores, and 1.4% (95% CI 0.8-2.1%) experienced MACE within 72 hours. Lower risks were observed in those with low HEART scores at 0.7% (95% CI 0.02-3.9%) and intermediate scores at 1.3% (95% CI 0.8-2.1%), compared to 3.8% (95% CI 0.8-10.6%) in the high-score group. A lower likelihood of 72-hour MACE was linked to the absence of highly suspicious symptoms (aOR 0.24; 95% CI 0.08-0.77) and reassuring high-sensitivity troponin-T levels (aOR 0.15; 95% CI 0.04-0.58), with 0.7% (95% CI 0.3-1.4%) affected in this subgroup. In the lowest-risk group, MACE occurred at a median of 56 (IQR 31-122) hours and 100 (IQR 43-131) hours.  

Investigators concluded that in a large cohort within the ED observation unit, the risk of 72-hour MACE was low, particularly in those with low or intermediate HEART scores and a favorable combination of symptoms and troponin levels. 

Source: jem-journal.com/article/S0736-4679(25)00045-9/abstract