Development of a novel risk prediction tool for emergency department patients with symptoms of coronary artery disease: A research study protocol

Patients with chest pain and symptoms of acute coronary syndromes (ACS) account for over 600,000 emergency department (ED) visits annually in Canada. Over 80% of these patients do not have ACS, and most are discharged from the ED after a thorough evaluation. However, a large proportion of these patients are referred for outpatient objective cardiac testing after ED discharge, even though their short-term risk for major adverse cardiac events (MACE) such as death, new myocardial infarction or need for revascularization is very small. This contributes to substantial low-value healthcare utilization, and limits access for those patients who are more likely to benefit from objective testing. Existing risk prediction tools were developed prior to the advent of high-sensitivity cardiac troponin assays, were derived in non-representative populations and, when applied to ED patients with low cardiac troponin concentrations, systematically overestimate short-term risk of (MACE). This multicenter prospective cohort study will enrol ED patients with chest pain to derive and validate a novel risk prediction tool to accurately identify patients at low risk of MACE and not requiring additional cardiac testing from patients who are likely to benefit from additional cardiac testing. We will enroll 6500 patients at 13 Canadian EDs nd prospectively follow them for 30 days to ascertain a primary outcome of MACE. The risk prediction tool developed in this project will guide safe, efficient, appropriate referrals of ED patients with chest pain.