Background: European guidelines recommend the use of a 0h/1h hs-cTn (high-sensitivity cardiac troponin) protocol in patients with acute chest pain. We aimed to determine the performance of this protocol in routine care when supplemented with patient history and ECG and a recommendation to refrain from noninvasive testing in low-risk patients.
Methods and results: This was a pre- and postimplementation study with concurrent controls. Patients with chest pain were enrolled at 5 Swedish emergency departments (EDs) during a 10-month period in both 2017 and 2018. All hospitals used a 0h/3h hs-cTnT protocol in 2017 and 3 EDs implemented a 0h/1h hs-cTnT protocol during 10 months in 2018. The 2 coprimary outcomes were the incidence of acute myocardial infarction and all-cause death within 30 days and ED length of stay. The study included 26 040 consecutive patients. In the intervention hospitals, 21 (0.40%) of the discharged patients had an acute myocardial infarction/death event during the control period (0h/3h testing) and 22 (0.45%) in the intervention period (0h/1h testing), which met the criteria for noninferiority. There was no significant difference in ED length of stay (ratio 0.99, P=0.48) or ED discharge rate between the periods in the intervention versus the control hospitals. A total of 3142 patients met low-risk 0h/1h hs-cTnT criteria and were discharged, of whom 2 had an acute myocardial infarction/death event.
Conclusions: A 0h/1h hs-cTnT protocol incorporating patient history and ECG was as safe as using a 0h/3h protocol but did not reduce ED length of stay or increase the discharge rate. Refraining from noninvasive testing in patients identified as low risk was safe.
Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03421873.
Keywords: acute coronary syndrome; chest pain; diagnosis; myocardial infarction; sensitivity and specificity.