Hess et al reported the North American Chest Pain Rule (NACPR). This can help to identify a patient at low risk who can have an early discharge. The authors are from the Mayo Clinic.
Acute coronary syndromes: cardiac death, acute myocardial infarction, or unstable angina
Parameters:
(1) age in years
(2) acute ischemic ECG changes
(3) known coronary disease
(4) pain typical for acute coronary syndrome (ACS)
(5) serum troponin concentration, measured at 0 and 6 hours
|
Parameter
|
Finding
|
Points
|
|
age in years
|
< 50 years
|
0
|
|
|
>= 50 years
|
1
|
|
acute ischemic changes in ECG
|
no
|
0
|
|
|
yes
|
1
|
|
known coronary disease
|
no
|
0
|
|
|
yes
|
1
|
|
typical chest pain
|
no
|
0
|
|
|
yes
|
1
|
|
serum troponin
|
<= 99th percentile
|
0
|
|
|
> 99th percentile
|
1
|
where:
• This is the rule as reported by Mahler et al. The original rule used a criterion: either age <= 40 years OR age 41-50 years with repeat troponin at 6 hours.
• In the original rule only the initial serum troponin measurement is needed for a patient <= 40 years.
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 5
• The higher the score the greater the risk of an acute coronary syndrome.
• A patient with a score of 0 is very low risk for ACS.
Performance:
• The sensitivity is 100% with specificity 21% for cardiac event within 30 days.
