Validation of a triage flowchart to rule out acute coronary syndrome

Area of Science:

• Emergency Medicine
• Cardiology
• Clinical Triage

Background:

• Acute coronary syndrome (ACS) is a critical diagnosis in emergency department (ED) chest pain presentations.
• Effective triage tools are essential to accurately identify patients with and without ACS.
• Previous models exist, but their validation in diverse patient populations requires ongoing assessment.

Purpose of the Study:

• To validate a previously derived five-step triage flowchart for ruling out ACS in emergency department chest pain patients.
• To compare the performance of a five-step model with a simplified four-step model.

Main Methods:

• An observational cohort study included 4231 consecutive chest pain patients in the ED.
• A five-step triage flowchart (age ≤ 40, no diabetes, no prior CAD, non-oppressive/non-retrosternal pain) was applied.
• Patients were categorized, and outcomes were assessed via ED study and 1-month follow-up to determine true ACS or non-ACS status.

Main Results:

• The five-step triage flowchart demonstrated 100% specificity and 100% positive predictive value (PPV) for ruling out ACS, classifying 5.2% of patients as 'triage non-ACS'.
• None of the patients classified as 'triage non-ACS' by the five-step model had true ACS.
• A four-step model (excluding age ≤ 40) had lower specificity (97%) and PPV, misclassifying 26 true ACS patients.

Conclusions:

• The five-step triage flowchart is highly effective in identifying chest pain patients without ACS, offering excellent specificity.
• However, its stringent criteria mean only a small proportion (5%) of patients qualify, limiting its widespread use for ruling out ACS.
• A simpler four-step model increases patient inclusion but carries a higher risk of misclassifying true ACS cases.