We aimed to assess the patients' experience of threat during management of an acute coronary syndrome (ACS) in the Emergency Department (ED) and to analyze the impact of this acute stress on day-30 outcomes.

This is a prospective study.

We included patients with ACS in the ED. After discharge, the perceived stress (Perceived Stress Scale (PSS); Visual Analogic Scale (VAS) in stress evaluation; Patient Health Questionnaire (PHQ); and Posttraumatic Stress Disorder Checklist Scale (PCLS) were used.

35 patients have developed PTSD on day-30 (31.8%). The independent predictors of developing PTSD at day-30 were high PSS score on admission (OR = 1.4; CI = 1.1–1.8; p = 0.004) and/or elevated PHQ-9 score at day-30 (OR = 1.5; CI = 1.2–1.9; p < 0.001).

The recurrence of the chest pain was more frequent in the PTSD group of patients. Patients with PTSD symptoms were more likely to report a non-therapeutic adherence to their cardiovascular medication.

Stress management in EDs should become a systematic step in the management of patients with ACS. This study emphasizes the importance of multidisciplinary follow-up and early screening of patients at risk of PTSD to improve their outcomes after discharge.