Introduction:Patients refusing transportation is common EMS practice with potentially fatal outcomes. Determining which patients are at high risk for poor outcomes is poorly defined. This study described patients who experienced an out-of-hospital cardiac arrest (OHCA) within 24 hours of refusing transportation.Method:This is a retrospective, descriptive study of patients who had an OHCA within 24 hours of refusing EMS transportation between 2019 to 2021. Data was obtained from a large, urban medical control authority seeing 175,000 EMS calls annually. We reviewed patient demographics, EMS events when transportation was refused, and cardiac arrest outcome.Results:There were 6, 30, and 28 EMS refusals resulting in OHCA in 2019, 2020, and 2021. Patients who had OHCA were 65.7 (range 28-103) years old, and African American (54/64). Patients had HTN (36/64), diabetes (19/64), COPD (11/64), and CHF (7/64). Common complaints included breathing problems (17/64), near syncope (8/64) however chest pain was uncommon (4/64). One (28/64) or two (13/64) abnormal vital signs were present and missing vital signs (28/64) were common. Tachycardia (32.8%, 21/64), HTN (29.7%, 19/64), and hypotension (17.2%, 11/64) were more prevalent in the OHCA population compared to all refusal patients (Tachycardia 0.33% [1,978/598,416], HTN 2.27% [13,601/598,416], and hypotension 0.04% [218/598,416]). Patients were seen by both ALS (29/64) and BLS (35/64) providers. Most providers documented risk including death (38/64) though few contacted medical control (14/64). Return encounter for OHCA resulted in obvious deaths (23/64) or field termination (20/64). Few patients achieved ROSC (7/64).Conclusion:Patients who had an OHCA within 24 hours of refusing transport had underlying comorbidities and abnormal or missing vital signs. The patients experienced tachycardia, hypertension, and hypotension at a higher rate than the overall refusal population. Few patients obtained ROSC. Further research is needed to determine methods to mitigate poor outcomes and decrease refusals.