Factors associated with late presentation to the emergency department in patients complaining of chest pain

•The prognosis of patients with acute coronary syndrome (ACS) depends on early diagnosis and treatment.•Chest pain onset presents more than 6 h prior to ED arrival in up to 38.5% of patients with chest pain and a final diagnosis of ACS.•Chest pain aggravated by exercise and recurrent chest pain were associated with both late presentation and a final diagnosis of ACS.•Educational initiatives should highlight these features as potential warnings for ACS and thereby encourage patients to seek prompt medical advice.