Of those with CP 7% will have EKG changes and 6-10% will have troponin changes. 5-15% have ACS.
Low risk = patients who have "chest pain" or ischemic symptoms but no evidence of ACI or infarction— no characteristic ECG changes and normal levels of cardiac markers
Recent cardiac cath reports are useful because a truly negative result is associated with a very low incidence of subsequent infarction or ACS in the next 2 years.
Recent negative evaluation for ACS that included stress testing have a 6-month incidence of ACS as high as 14%...