The goal of this proposal is to improve the quality and value of care for patients with acute chest pain by investigating the potential impact of point-of-care (POC) high sensitivity cardiac troponin (hs-cTn) testing in the Emergency Department (ED) and exploring how best to integrate POC hs-cTnl into ED risk stratification workflows. The study hypothesizes that the Abbott i-STAT POC hs-cTnI assay will decrease time-to-result (TTR) and ED length of stay (LOS), while increasing ED revenue for patients with acute chest pain compared to a strategy of central laboratory hs-cTnI testing.

Use of point-of-care (POC) testing in the Emergency Department (ED) has been previously established as a method to reduce the time-to-disposition-decision (TTD) making for emergency physicians, which in-turn can reduce ED length of stay (LOS) and time-to-treatment (TTT) of time sensitive conditions, such as myocardial infarctions (MIs). Recently, new POC high sensitivity cardiac troponin I (hs-cTnI) assays have been developed which offer similar diagnostic performance to traditional central lab hs-cTnI testing. However, data examining POC hs-cTnI measurement in U.S. ED settings are limited. In particular, studies have yet to evaluate the potential impact of POC hs-cTnI implementation on time to troponin result (TTR), time-to-last-troponin-result (TTLT), time-to-disposition-decision (TTD), time-to-treatment (TTT), and ED LOS. In addition, limited data exists on how best to implement POC hs-cTnI into ED clinical practice, such as whether POC hs-cTnI measures should be paired with a risk score or incorporated into an accelerated diagnostic protocol.

This record is a prospective multisite observational cohort study of 600 adult ED patients with symptoms suggestive of acute coronary syndrome and without ST-segment elevation myocardial infarction (STEMI) across 3 EDs. Participants, accrued under a waiver of informed consent, will undergo a standard-of-care evaluation for possible acute coronary syndrome (ACS) in the ED including blood testing for hs-cTnI (Beckman Coulter) completed in a central laboratory. During the study period all ED patients with chest pain will have an extra lithium heparin blood sample obtained for each troponin test ordered and collected in the ED (typically 2, but this may range from 1-3 troponin measures), which will be used for immediate hs-cTnI measurement by research personnel using an Abbott i-STAT Alinity. Clinicians will be blinded to the POC hs-cTnI results and will base clinical decisions on central laboratory hs-cTn measures. Blood draw times, result times for point-of-care (POC) and central laboratory measures, patient ED arrival, patient ED bedded, ED disposition decision times, and ED discharge times will be recorded on all patients. Following each POC hs-cTnI measurement the treating attending physician will be surveyed regarding whether a negative or positive POC result would change ED disposition or treatment including time stamps to determine estimated TTD, ED LOS and TTT for the POC hs-cTnI measurement strategy. Data from these surveys will be compared to actual TTD, ED LOS and treatment times based on the central laboratory hs-cTnI measurement strategy.

Inclusion Criteria:

• Age greater than or equal to18 years
• Symptoms suggestive of acute coronary syndrome:
• Acute chest, epigastric, neck, jaw or arm pain or discomfort or pressure without apparent non-cardiac source
• Shortness of breath, nausea, vomiting, fatigue/malaise, or
• Other equivalent discomfort suggestive of an myocardial infarction (MI)
• Electrocardiogram (ECG) ordered as part of standard of care
• At least one troponin collected as standard of care
• Study specific blood sample collected within ± 5 minutes of clinical draw

Exclusion Criteria:

• ST-segment elevation myocardial infarction (STEMI) Activation
• Unstable vitals signs: symptomatic hypotension at the time of enrollment (systolic < 90 mm Hg), tachycardia (HR>120), bradycardia (HR<40), and hypoxemia (<90% pulse-oximetry on room air or normal home oxygen flow rate)
• Central laboratory hs-cTn testing resulted or in process (>5 minutes) prior to study accrual
• Prior enrollment
• Terminal diagnosis with life expectancy less than 6 months

Adults (≥18 years old) presenting to the ED with symptoms concerning for acute coronary syndrome (ACS) and an ECG and troponin ordered as part of standard of care, will be eligible for accrual. Patients with STEMI activation or unstable vital signs will be excluded. In addition, patients will be required to have a (extra) lithium heparin blood sample collected within ± 5 minutes of their clinical draw for hs-cTnI. Patients with central laboratory hs-cTnI testing or a hs-cTnI measure resulted prior to study accrual also be excluded.