Utility of Routine Exercise Stress Testing among Intermediate Risk Chest Pain Patients Attending an Emergency Department

Background To assess the utility of routine exercise stress testing (EST) in patients at intermediate risk of acute coronary syndrome (ACS) according to the Heart Foundation of Australia/Cardiac Society of Australia and New Zealand (HFA/CSANZ) guidelines. Method Prospective observational study of patients presenting to the Emergency Department (ED) with chest pain suggestive of ACS between November 2008 and July 2014. Participants included 1205 patients who presented to the ED with chest pain suggestive of ACS and who met the HFA/CSANZ intermediate risk criteria. The outcome was diagnosis of ACS occurring on presentation or within 30 days of presentation to the ED. ACS included acute myocardial infarction and unstable angina pectoris. Results Twenty (1.66%) of the intermediate risk patients were diagnosed with ACS. Of the 777 patients who underwent EST, eight had ACS. EST identified all ACS cases except for one patient with a negative test, who was ultimately diagnosed with ACS following angiography. 164 patients deemed inappropriate to undergo EST underwent an alternative form of objective testing, of which 12 were positive for ACS. 264 patients underwent no objective testing. Conclusion EST stratifies intermediate risk patients to a near zero short-term risk of ACS. However, the overall yield of EST within this group of patients is extremely low. Intermediate risk patients with normal zero and six hour biomarkers have a very low probability of ACS, and over half of these patients ultimately diagnosed with ACS in this group were deemed unsuitable for EST anyway. Future research should focus on the identification of patients who do not require EST and the inclusion of routine EST within the HFA/CSANZ guidelines should be reconsidered.