Implementation of high-sensitivity troponin with a rapid diagnostic algorithm reduces emergency department length of stay for discharged patients.

INTRODUCTION: High sensitivity troponin (hs-cTn) and diagnostic algorithms are used to rapidly triage patients with symptoms of acute myocardial infarction in emergency departments (ED). However, few studies have evaluated the impact of simultaneously implementing hs-cTn and a rapid rule-out algorithm on length of stay (LOS). METHODS: We assessed the impact of transitioning from contemporary cTnI to hs-cTnI in 59,232 ED encounters over three years. hs-cTnI was implemented with an orderable series that included baseline, two-, four-, and six-hour specimens collected at provider discretion and operationalized with an algorithm to calculate the change in hs-cTnI from baseline and provide interpretations of "insignificant", "significant," or "equivocal." Patient demographics, results, chief complaint, disposition, and ED LOS were captured from the electronic medical record. RESULTS: cTnI was ordered for 31,875 encounters prior to hs-cTnI implementation and 27,357 after. The proportion of cTnI results above the 99th percentile upper reference limit decreased from 35.0% to 27.0% for men and increased from 27.8% to 34.8% for women. Among discharged patients, the median LOS decreased by 0.6 h (0.5-0.7). LOS among discharged patients with a chief complaint of chest pain decreased by 1.0 h (0.8-1.1) and further decreased by 1.2 h (1.0-1.3) if the initial hs-cTnI was below the limit of quantitation. The rate of acute coronary syndrome upon re-presentation within 30 days did not change post-implementation (0.10% versus 0.07%). CONCLUSION: Implementation of an hs-cTnI assay with a rapid rule-out algorithm decreased ED LOS among discharged patients, particularly among those with a chief complaint of chest pain.

Serial cardiac biomarkers for risk stratification of patients with COVID-19.

OBJECTIVES: Several studies have demonstrated an association between elevated cardiac biomarkers and adverse outcomes in patients with COVID-19. However, the prognostic and predictive capability of a multimarker panel in a prospectively collected, diverse "all-comers" COVID-19 population has not been fully elucidated. DESIGN & METHODS: We prospectively assessed high sensitivity cardiac troponin I (hsTnI), NT-pro B-type Natriuretic Peptide (NT-proBNP), Galectin-3 (Gal-3), and procalcitonin (PCT) in 4,282 serial samples from 358 patients admitted with symptomatic, RT-PCR confirmed SARS-CoV-2 infection. Outcomes examined were 30-day in-hospital mortality and requirement for intubation within 10 days. RESULTS: Baseline hsTnI had the highest AUC for predicting 30-day mortality (0.81; 95% CI, 0.73-0.88), followed by NT-proBNP (0.80; 0.74-0.86), PCT (0.77; 0.70-0.84), and Gal-3 (0.68; 0.60-0.76). HsTnI < 3.5 ng/L at baseline identified patients at low risk for in-hospital mortality (NPV 95.9%, sensitivity 97.3%) and 10-day intubation (NPV 90.4%, sensitivity 88.5%). Continuous, log-2 increases in troponin concentration were associated with reduced survival (p < 0.001) on Kaplan-Meier curves and increased risk of 30-day mortality: HR 1.26 (1.16-1.37) in univariate and 1.19 (1.03-1.4) in multivariate models. Time-varying doubling of concentrations of hsTnI and Gal-3 were associated with increased risk of 30-day mortality (adjusted HR 1.21, 1.06-1.4, and 1.92, 1.40-2.6). CONCLUSION: HsTnI, NT-proBNP, Gal-3, and PCT are elevated at baseline in patients that have worse outcomes from COVID-19. HsTnI was the only independent predictor of 30-day mortality and intubation. Time-varying, doubling in hsTnI and Gal-3 further aided in prognostication of adverse outcomes. These results support the use of hsTnI for triaging patients with COVID-19.