RE-ACT is a national, multi-centre, observational, prospective, longitudinal cohort study which will include patients hospitalized for ACS within 24 hours of symptom onset and who have a final diagnosis of ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI). This study aims to describe the short-term (at the end of the first month after index event) antithrombotic management patterns in a "real-life" setting for patients hospitalized with an acute coronary syndrome.

Inclusion Criteria:

• Provision of subject informed consent
• Patients hospitalized and diagnosed with STEMI or NSTEMI
• Hospitalized within 24 hours of onset of symptoms or transferred from another hospital within 24 hours of the onset of symptoms

Exclusion Criteria:

• STEMI and NSTEMI precipitated by or as a complication of surgery, trauma, or GI bleeding or post-PCI.
• STEMI and NSTEMI occurring in patients already hospitalized for other reasons.
• Presence of any condition/circumstance which in the opinion of the investigator could significantly limit the complete follow up of the patient (e.g. tourist, non-native speaker or does not understand the local language, psychiatric disturbances).

Patients aged 18 years or older, hospitalized and diagnosed with STEMI (ST-segment elevation myocardial infarction) or NSTEMI (non-ST-segment elevation myocardial infarction) within 24 hours of symptom onset.