Inclusion Criteria:  All out-of-hospital chest pain patients visited by an ambulance Transportation to a hospital with working diagnosis NSTE-ACS Age ≥ 18 years  Exclusion Criteria:  Comatose state, hemodynamic instability or shock Electrocardiographic ST-segment elevation in the pre-hospital setting No pre-hospital 12-lead electrocardiogram performed or available An obvious non-cardiac cause for the chest pain (trauma, etc.) Suspicion of aortic dissection or pulmonary embolism Cognitive impairment Pregnancy