Abstract Body (Do not enter title and authors here): Background: Emergency department (ED) overcrowding is a significant healthcare challenge that continues to strain medical facilities internationally. The need to assess myocardial injury in the ED is thought to be common, accounting for greater than 13 million visits annually. Therefore, we sought to assess the frequency and impact of myocardial injury assessment on the intermediates to ED overcrowding – ED disposition distribution and time to disposition – at an urban ED.

Methods: In this single-center, retrospective cohort study from February 1, 2023, to January 31, 2024, the disposition distribution and median time to disposition were recorded for ED patient encounters. The study population was divided into encounters resulting in ED assessment for myocardial injury with conventional troponin measurement (ED-Tn group) and all other encounters without ED assessment for myocardial injury (control group). Pearson test was used for analyzing disposition distribution and Wilcoxon test for comparing time to disposition between the two defined groups.

Results: 66,984 patient encounters resulted in a disposition of discharge or admission during the study period. 15,918 (23.8%) were categorized into ED-Tn group, while 51,066 (76.2%) were categorized into control group. The ED-Tn group had a significantly lower discharge frequency of 51% compared to the control group with 59.1% (p<0.001). The median time to disposition was significantly higher for the ED Tn group at 212 minutes (IQR = 124, 325) compared to the control group at 184 minutes (IQR = 95, 313; p<0.001). When considering only those patients who were discharged from the ED, the difference in median time to disposition was even more pronounced for the ED-Tn group at 226 minutes (IQR = 139, 340) compared to the control group at 178 minutes (IQR = 86, 311; p<0.001).

Conclusions: In an urban ED, myocardial injury assessments comprised a quarter of all ED evaluations, linked to increased admission and extended time to disposition for these patients. Implementing high-sensitivity troponin could improve efficiency of ED assessment for myocardial injury and alleviate overcrowding, given the resource-intensive and time-intensive nature of these assessments.