External validation of a rapid algorithm using high-sensitivity troponin assay results for evaluating patients with suspected acute myocardial infarction

Louise Cullen; Jaimi H Greenslade; Laura Stephensen; Isuru Ranasinghe; Niranjan Gaikwad; Maryam Khorramshahi Bayat; Ehsan Mahmoodi; Martin Than; Fred Apple; William Parsonage; 2022 SAMIE study group

doi:10.1136/emermed-2023-213539

External validation of a rapid algorithm using high-sensitivity troponin assay results for evaluating patients with suspected acute myocardial infarction

Emerg Med J. 2024 Apr 22;41(5):313-319. doi: 10.1136/emermed-2023-213539.

Authors

Louise Cullen¹, Jaimi H Greenslade^{2

3}, Laura Stephensen^{2

3}, Isuru Ranasinghe^{4

5}, Niranjan Gaikwad⁵, Maryam Khorramshahi Bayat⁵, Ehsan Mahmoodi⁵, Martin Than⁶, Fred Apple⁷, William Parsonage^{8

9}; 2022 SAMIE study group

Affiliations

¹ Emergency and Trauma Centre, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia louise.cullen@health.qld.gov.au.
² Department of Emergency Medicine, Royal Brisbane and Women\'s Hospital, Herston, Queensland, Australia.
³ School of Public Health, Queensland University of Technology, Brisbane, Queensland, Australia.
⁴ Cardiology, The University of Queensland, Saint Lucia, Queensland, Australia.
⁵ The Prince Charles Hospital, Chermside, Queensland, Australia.
⁶ Emergency Department, Christchurch Hospital, Christchurch, New Zealand.
⁷ Hennepin County Medical Center, Minneapolis, Minnesota, USA.
⁸ Royal Brisbane & Women's Hospital, Brisbane, Queensland, Australia.
⁹ Queensland University of Technology, Brisbane, Queensland, Australia.

PMID: 38316538
DOI: 10.1136/emermed-2023-213539

Abstract

Objective: We sought to validate the clinical performance of a rapid assessment pathway incorporating the Siemens Atellica IM high sensitivity cardiac troponin I (hs-cTnI) assay in patients presenting to the emergency department (ED) with suspected acute myocardial infarction (AMI).

Methods: This was a multicentre prospective observational study of adult ED patients presenting to five Australian hospitals between November 2020 and September 2021. Participants included those with symptoms of suspected AMI (without ST-segment elevation MI on presentation ECG). The Siemen's Atellica IM hs-cTnI laboratory-based assay was used to measure troponin concentrations at admission and after 2-3 hours and cardiologists adjudicated final diagnoses. The HighSTEACS diagnostic algorithm was evaluated, incorporating hs-cTnI concentrations at presentation and absolute changes within the first 2 to 3 hours. The primary outcome was index AMI, including type 1 or 2 non-ST segment elevation MI (NSTEMI) or ST-elevation MI (STEMI) following presentation. 30-day major adverse cardiac outcomes (including AMI, urgent revascularisation or cardiac death) were also reported. The trial was registered with the Australian and New Zealand Clinical Trials Registry.

Results: 1994 patients were included. The average age was 56.2 years (SD=15.6), and 44.9% were women. 118 (5.9%) patients had confirmed index AMI. The 2-hour algorithm defined 61.3% of patients as low risk. Sensitivity was 99.1% (94.0%-99.9%) and negative predictive value was 99.9% (99.3%-100%). 24.4% of patients were deemed intermediate risk. When applying the parameters for high risk, 252 (14.3%) were identified, with a specificity of 91.5% (88.7%-93.6%) and a PPV of 42.0% (35.6-48.7%).

Conclusions: A 2-hour algorithm based on the HighSTEACS strategy using the Siemens Atellica IM hs-cTnI laboratory-based assay enables safe and efficient risk assessment of emergency patients with suspected AMI.

Trial registration number: ACTRN12621000053820.

Keywords: acute coronary syndrome.