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Suspected Myocardial Infarction · PRESC1SE-MIThe 0/1 h Troponin Pathway at Late-Adopting Hospitals: As Safe as 0/3 h, but No Shorter ED Stay
PRESC1SE-MI set out to show that switching from the 0/3 h to the guideline-preferred 0/1 h pathway would be at least as safe and would move patients through the emergency department faster. We review the high-level findings.
Published on MedED: [DD Month 2026]
Type of article: Narrative review of a trial’s design and primary results
Compiler: [Contributor Name]
Catalogue Number: [CATALOGUE]
Platform: www.meded.co.za
AI may have been used to assist in preparing this article. The content is intended as an overview only and does not replace the original sources. Medical Education Network strongly encourages all members to review the original material before forming clinical opinions or making decisions.
Where this review draws from
This article brings together two reports of a single trial, PRESC1SE-MI. Both are listed in full in the References:
Boeddinghaus et al. (The Lancet, 2026) — primary results · Boeddinghaus et al. (American Heart Journal, 2026) — rationale and design · European Society of Cardiology press release (29 August 2026) — ESC Congress 2026 presentation, direct-discharge result, individual participant data meta-analysis and investigator commentary.
Neither journal article is open access. Readers are encouraged to consult the full papers through their institutional subscriptions.
Attribution
This article is compiled from a variety of resources researched and compiled by the contributor. It is in no way presented as an original work. Every effort has been made to correctly attribute content.
The source articles are subscription-access publications. This review restates their content in the Medical Education Network’s own words and does not reproduce their text, tables or figures. Copyright in the original articles remains with their authors and publishers. The chart has been redrawn from figures reported in the original article.
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The Question the Trial Asked
The assessment of patients with suspected myocardial infarction relies on serial measurements of high-sensitivity cardiac troponin. International guidelines recommend the European Society of Cardiology (ESC) 0/1-hour algorithm, which requires a second sample at one hour, as the preferred triage strategy, with the 0/3-hour algorithm remaining an acceptable alternative.1,2
Despite this recommendation, many hospitals worldwide continue to use the 0/3-hour pathway, having yet to adopt the faster 0/1-hour approach. Uncertainty remains over whether the shorter testing interval offers a better balance of safety and clinical effectiveness in routine practice. According to the trial's design paper, no large, prospective, international randomised trial had previously evaluated the safety and effectiveness of implementing the 0/1-hour algorithm in these late-adopting centres across different countries and healthcare systems.2
How the Trial Was Designed
The protocol
PRESC1SE-MI (PRospective Evaluation of the European Society of Cardiology 0/1h-algorithm’s Safety and Efficacy for Triage of Patients with Suspected Myocardial Infarction) is an investigator-initiated, international, multicentre trial with a stepped-wedge, cluster-randomised design.2 Its design paper describes it as the largest international multicentre trial so far to evaluate implementation of the 0/1 h algorithm at late-adopting centres across several countries and healthcare systems.2
Eligible participants were consecutive adults who present to the ED with acute, non-traumatic chest discomfort and suspected MI. Sites still using the 0/3 h algorithm as standard care were randomised to change to the 0/1 h algorithm at either an early or a late implementation step. Throughout the preceding validation phase, every site kept using the 0/3 h algorithm.2
The trial was built to show non-inferiority for safety and superiority for efficacy, with power of at least 90%, and set a target of at least 52,156 consecutive patients.2 The investigators anticipated that the trial could improve patient care, ease ED overcrowding and reduce healthcare costs.2
The trial as conducted
The results paper reports that 19 hospitals in ten countries took part. Hospitals were randomly assigned to start using the 0/1 h pathway after six months (early implementation) or after 12 months (late implementation). Endpoints were assessed with masking, and analyses were carried out in the full analysis set.1
What the Trial Found
The results were presented by co-principal investigator Professor Jasper Boeddinghaus (University Hospital Basel and University Hospital Bonn) in a Hot Line session at ESC Congress 2026 in Munich on 29 August 2026, and were published simultaneously in The Lancet.3
From 1 December 2020 to 31 December 2024, the investigators screened 71,983 consecutive patient presentations. Of these, 67,624 (93.9%) met the eligibility criteria and made up the full analysis set. A total of 36,464 presentations were managed under the 0/3 h pathway and 31,160 under the 0/1 h pathway.1
Safety: non-inferiority met
Death from any cause or new type 1 MI within 30 days occurred in 454 presentations (1.2%) in the 0/3 h group and 341 (1.1%) in the 0/1 h group. The adjusted odds ratio was 0.93 (95% CI 0.77–1.13), with a p value for non-inferiority of 0.0004, meeting the prespecified non-inferiority criterion.1
Efficacy: no reduction in ED length of stay
Median ED length of stay was 309 minutes (IQR 203–470) with the 0/3 h pathway and 309 minutes (IQR 207–474) with the 0/1 h pathway. The ratio of adjusted median times was 1.00 (95% CI 0.97–1.02; two-sided p=0.65). The 0/1 h pathway therefore did not shorten ED stay compared with the 0/3 h pathway.1
Direct discharge from the ED
The ESC press release adds that the 0/1 h pathway did not increase direct discharge from the ED. It reports no figures for this outcome.3
The wider evidence: individual participant data meta-analysis
The same Hot Line session included a meta-analysis of individual participant data from PRESC1SE-MI and every other available randomised trial comparing the 0/1 h pathway with standard pathways. Across five trials and 110,933 patient presentations, the 0/1 h pathway gave safety similar to standard care. As in PRESC1SE-MI, it neither shortened ED length of stay nor increased direct discharge from the ED.3
For South African Practitioners
Scope note: The trial reports summarised here do not present South African data, and their results cannot be used to estimate local outcomes or ED length of stay.
In Conclusion
PRESC1SE-MI was designed to test two propositions at hospitals that had not yet adopted the guideline-preferred strategy: that the 0/1 h algorithm is at least as safe as the 0/3 h algorithm, and that it is more effective at moving patients through the ED.2
Across 67,624 presentations, the first proposition was confirmed: the 0/1 h pathway met its prespecified non-inferiority criterion for death or new type 1 MI at 30 days. The second was not, with median ED length of stay identical at 309 minutes under both pathways. The investigators conclude that implementing the 0/1 h pathway alone should not be expected to improve ED throughput.1
An individual participant data meta-analysis of five randomised trials, presented alongside the trial at ESC Congress 2026, pointed the same way: similar safety, with no reduction in ED length of stay and no increase in direct discharge.3
References
- Boeddinghaus, J., [co-authors to be confirmed]. (2026). Safety and efficacy of the 0/1 h pathway for myocardial infarction in the emergency department: An international, pragmatic, stepped-wedge, cluster-randomised, controlled trial. The Lancet. Advance online publication. https://doi.org/10.1016/S0140-6736(26)01654-5
- Boeddinghaus, J., Bima, P., Crisanti, L., Keller, D. I., Slankamenac, K., Christ, M., Schuetz, P., Wiencierz, A., Strebel, I., Reinhardt, J., Vyshnevska, I., Tsao, T. Y., Mahfoud, F., Ruggieri, M. P., Steuer, S., Miró, Ò., Harjola, V. P., Morello, F., Nazerian, P., . . . Mueller, C. (2026). PRospective evaluation of the European Society of Cardiology 0/1h-algorithm’s safety and efficacy for triage of patients with suspected myocardial infarction (PRESC1SE-MI): Rationale and design of a prospective international multicenter stepped-wedge cluster randomized controlled trial. American Heart Journal, 292, Article 107299. https://doi.org/10.1016/j.ahj.2025.107299
- European Society of Cardiology. (2026, August 29). Rapid testing for heart attacks does not reduce length of emergency department stay [Press release]. https://www.escardio.org/news/press/press-releases/rapid-testing-for-heart-attacks-does-not-reduce-length-of-emergency-department-stay/
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Disclaimer. This article is compiled from a variety of resources researched and compiled by the contributor. It is in no way presented as an original work. AI may have been used to assist in preparing this article. Every effort has been made to correctly attribute quotes and content. Where possible, all information has been independently verified. The Medical Education Network bears no responsibility for any inaccuracies which may occur from the use of third-party sources. The Medical Education Network urges all practitioners to review the original material as their clinical reference. If you have any queries regarding this article contact us
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