Useful for screening patient with low<unk>  for ACS
The old Vancouver chest pain rule was not properly validated 
The new rule was validated in 2014 on 1635 patients and published in 2014
With high sensitivity troponins the sensitivity is 99.1% (95% CI 97.4-99.7), & specificity is 16.1 (95% CI 14.2-18.2)
With sensitive troponin-I the sensitivity was 98.8% (97.0-99.5), & specificity of 15.8 (13.9-17.9)
Is the same for c-TnI assay and hs-TnI assay but sensitivity differences by a percentage point
If Yes to any then no early discharge
If Yes then early discharge
If Yes then no early discharge
If answer is No to all of the above stepwise questions then the patient can have early discharge with close follow-up for further provocative testing
ACS - Risk Stratification
Unstable Angina - NSTEMI Guidelines
ACS - Stress Testing
Denver screening criteria
Modified Wells Score
ADDIE system
Harbor Macros: EKG
LLSA Readings: 2012