Unstable angina: determining patient's risk helps to predict need for intensive care.
Clinical bottom line (level 1a)
A sixth of patients with acute chest pain who are in a high risk group will have a first major event (requiring admission to intensive care) within 72 hours.
A twelfth of patients in a moderate risk group will have a first major event within 72 hours.
A twenty-fifth of patients in a low risk group will have a first major event within 72 hours.
Less than 1% of patients in a very low risk group will have a first major event within 72 hours.
Goldman et al:
New England Journal of Medicine
Expires March 2003
Inception cohort study
for confounding factors,
validated in an independent set of patients.
Setting: one hospital emergency department, USA
over 60y in 44% cases,
primary symptom of chest pain unexplained by obvious local trauma or abnormalities on the chest radiograph
- cardiac arrest
- left against medical advice
- insufficiently explicit interpretation of ECG
Data was validated using the chi-square test for association and the Mantel-Haenszel stratified test. The area under the receiver-operating-characteristic curve (measure of overall discrimination) was calculated and compared for various predictive models.
- rate of first major event in high risk group
(defined as those thought on a clinical basis to require intensive care)
- rate of first major event with moderate risk
- rate of first major event with low risk
- rate of first major event with very low risk
- Patients were assigned to one of four groups according to the risk of an event within 24 hours, from very low (0.3%) to high (16%). Five factors were used to assign patients to a risk group:
Patients were classified as:
- electrocardiographic evidence of an ST elevation or Q waves, not known to be old, in two or more leads
- ST segment or T wave changes, not known to be old, indicative of myocardial ischaemia
- pain worse than prior angina or the same as the pain associated with a prior myocardial infarction
- systolic blood pressure <110 mmHg
- rales above the bases bilaterally
- high risk: suspected MI on ECG or suspected ischaemia on ECG plus two or more risk factors
- moderate risk: suspected ischaemia on ECG and no or one risk factor
- low risk: just one risk factor (no MI or ischaemia)
- very low risk: no risk factor
||time to outcome
||number of patients/total number
| rate of first major event in high risk group
| rate of first major event with moderate risk
| rate of first major event with low risk
| rate of first major event with very low risk
- This study reinforces the utility of inexpensive "low technology" measures, namely--history, physical exam, and ECG to provide important prognostic data in patients being evaluated for chest pain.
- The derivation group of 10,682 patients were enrolled from seven emergency departments.
Contributor: Clare Wotton and Bob Phillips,
PA, et al:
Prediction of the need for intensive care in patients who come to emergency departments with acute chest pain.
New England Journal of Medicine
Reviewer: Arnold Baas
||acute chest pain
|Intervention or Exposure
||high risk, clinical and ECG factors