Enhanced triage for patients with suspected cardiac chest pain: the History and Electrocardiogram-only Manchester Acute Coronary Syndromes decision aid

1,929 adult patients presenting to the Emergency Department with suspected cardiac chest pain (796 in derivation cohort, 474 in validation cohort 1, 659 in validation cohort 2). Excluded if another medical condition necessitated hospital admission, symptoms occurred over 24h (or 12h in validation 2) prior to arrival, or diagnosed with STEMI in the ED.

History and ECG-only Manchester ACS (HE-MACS) decision aid, incorporating age, sex, systolic blood pressure, and five historical variables (sweating observed, acute ECG ischaemia, pain radiating to right arm/shoulder, vomiting associated with pain, current tobacco smoker) to stratify patients into four risk groups without biomarker measurement.

Acute coronary syndrome (ACS) at 30 days, defined as prevalent acute myocardial infarction (AMI) or at least one incident major adverse cardiac event (MACE) within 30 days.composite