The Limit of Detection in the ED Trial (LEGEND): hs-Troponin LoD Strategy to Rule Out AMI
Authors: Greenslade J, Parsonage W, Stephensen L, Parsons R, Perez S, Starmer K, Starmer G, Gaikwad N, McPhail SM, Hall E, Brownlee E, McCormick E, Cullen L
Journal: Annals of Emergency Medicine, December 2025
Conclusions:
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A limit-of-detection (LoD) hs-troponin strategy with shared decision-making safely rules out AMI and speeds ED flow.
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In patients with presentation hs-cTn ≤ 2 ng/L, the pathway shortened ED LOS, increased <4-hour discharges, and reduced downstream cardiac testing without increases in 30-day adverse events or representations.
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Practical takeaway: for low-risk suspected ACS with initial hs-cTn at or below LoD, a structured SDM discharge pathway can decongest the ED.
Results:
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Population: 9,944 suspected ACS patients across 4 Australian EDs
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Standard care: 5,347; LEGEND intervention: 4,597
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LEGEND cohort (presentation hs-cTn ≤ 2 ng/L):
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ED LOS: −3.6 hours vs standard care (95% CI −4.6 to −2.5).
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Discharged within 4 hours: +22.9% (95% CI +19.5% to +26.3%).
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Cardiac testing: −7.8% (95% CI −11.1% to −4.6%).
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Safety: No differences in representations, index events, or 30-day events.
Methods:
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Stepped-wedge cluster randomized controlled trial (4 EDs), Aug 2019–Jul 2020.
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Adult suspected ACS presentations; sites crossed over from standard care to the LEGEND LoD + SDM strategy.
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Primary outcome: ED length of stay.
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Secondary outcomes: <4-hour discharge, cardiovascular testing, representations, index events, 30-day events.
The Limit of Detection in the Emergency Department Trial (LEGEND): A Stepped-Wedge Cluster Randomized Trial to Rule Out Acute Myocardial Infarction and Reduce Hospital Length of Stay for Patients Presenting to the Emergency Department
Greenslade, JaimiGreenslade, Jaimi et al.
Annals of Emergency Medicine, Volume 0, Issue 0