An International, Stepped-Wedge, Cluster-Randomized Trial Investigating the 0/1-hour Algorithm in Suspected Acute Coronary Syndrome in Asia: The rational of the DROP-Asian ACS study

Abstract BackgroundMore than half of the world’s population lives in Asia. With current life expectancies in Asian countries, the burden of cardiovascular disease is increasing exponentially. Overcrowding in the emergency departments (ED) has become a public health problem. Since 2015, the European Society of Cardiology recommends the use of a 0/1-h algorithm based on high-sensitivity cardiac troponin (hs-cTn) for rapid triage of patients with suspected non-ST elevation acute coronary syndrome (NSTE-ACS). However, these algorithms are currently not recommended by Asian guidelines due to the lack of suitable data.MethodsThe DROP-Asian ACS is a prospective, stepped-wedge, cluster-randomized trial enrolling 4,080 participants presenting with chest pain to the ED of eleven centers in five Asian countries within 20.5 months (UMIN; 000042461). Initially, all clusters will apply 'usual care' according to local standard operating procedures including hs-cTnT but not the 0/1-h algorithm. Every 1.5 months, one cluster will randomly be allocated to switch to the 0/1-h algorithm using hs-cTnT. The primary outcome is the incidence of major adverse cardiac events (MACE), the composite of all-cause death, myocardial infarction, unstable angina or revascularization within 30 days. The difference in MACE (with one-sided 95% CI) was estimated to evaluate non-inferiority. The non-inferiority margin was prespecified at 1.5%. Secondary efficacy outcomes include costs for healthcare resources and duration of stay in ED. ConclusionsThis study provides important evidence concerning the safety and efficacy of the 0/1-h algorithm in Asian countries and may help to reduce congestion of the ED as well as medical costs.