Abstract
IMPORTANCE: Evaluation for myocardial infarction (MI) in emergency departments (EDs) is a common, resource-intensive process. High-sensitivity cardiac troponin I (hs-cTnI) assays have become a key tool in rapidly ruling out MI, with the potential to reduce health care resource utilization. OBJECTIVE: To determine whether a 0-hour and 1-hour (hereafter referred to as 0/1-hour) hs-cTnI accelerated protocol reduces health care resource utilization compared with a traditional 0/3-hour standard care protocol for MI exclusion in the ED. DESIGN, SETTING, AND PARTICIPANTS: This is a prespecified secondary analysis of the RACE-IT trial, a stepped-wedge randomized clinical implementation trial conducted across 9 EDs in Michigan. The trial enrolled 32 608 consecutive ED patients evaluated for suspected MI between July 8, 2020, and April 3, 2021. Statistical analysis was conducted from July 10 to September 5, 2024. INTERVENTIONS: The 0/1-hour hs-cTnI accelerated protocol for MI exclusion was compared with the traditional 0/3-hour standard care protocol. MAIN OUTCOMES AND MEASURES: Main outcomes were ED discharge to home, ED length of stay, rates of cardiac stress testing, cardiology consultation, left heart catheterization, and cardiac revascularization within 30 days. RESULTS: A total of 32 608 patients (median age, 59 years [IQR, 45-71 years]; 18 705 women [57.4%]) were included in the analysis. The rate of ED discharge to home was 58.0% for the accelerated protocol group (11 082 of 19 103) and 59.8% for the standard care group (8070 of 13 505) (adjusted odds ratio [AOR], 1.05; 95% CI, 0.95-1.15). The accelerated protocol group showed significant reductions in the odds of cardiac stress testing (3.3% [623 of 19 103] vs 3.9% [526 of 13 505]; AOR, 0.62; 95% CI, 0.49-0.78), cardiology consultations (8.6% [1640 of 19 103] vs 12.2% [1651 of 13 505]; AOR, 0.57; 95% CI, 0.49-0.67), and left heart catheterization rates (1.0% [198 of 19 103] vs 1.2% [167 of 13 505]; AOR, 0.65; 95% CI, 0.43-0.99) compared with the standard protocol group. The median ED length of stay decreased by 20 minutes (IQR, 18-24 minutes) in the accelerated protocol group, with no significant change in revascularization rates. CONCLUSIONS AND RELEVANCE: This secondary analysis of a randomized clinical trial of a 0/1-hour hs-cTnI protocol to rule out MI in the ED found that there was a reduction in cardiac evaluations and ED length of stay without increasing revascularization rates compared with the standard 0/3-hour hs-cTnI protocol. This approach could optimize health care resources in EDs. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04488913.