Effectiveness and Safety of the ESC‐TROP (European Society of Cardiology 0h/1h Troponin Rule‐Out Protocol) Trial

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.