0/1-hour versus standard care pathways in MIAcute Coronary SyndromesThe LancetOpen Access
Performance of 0/1 h versus 0/3 h pathways in patients with suspected myocardial infarction: a systematic review and individual participant data meta-analysis of randomised controlled trials
0/1-hour pathway yields similar 30-day death or type 1 MI rates versus 0/3-hour testing.
OR 0.83
95% CI 0.45-1.53
n=110,933
Discussion
Member takes
No takes yet. Share an insight, caveat, or question.
Expert perspectives 1
Author’s perspective
Jasper BoeddinghausDirector, Institute for Clinical Cardiovascular Science, University Hospital Bonn
“These findings are important to healthcare providers worldwide as they contradict current assumptions that implementing 0/1-hour testing improves patient management in the ED. It seems that other processes – including specialist review, admissions workflow and bed availability – may have a greater influence on ED length of stay than the testing strategy alone. Approaches such as integrating the 0/1-hour pathway into electronic healthcare records as a clinical decision-support tool may be beneficial to bring the benefits of rapid testing to patients and the healthcare system as a whole.”
Answers are grounded in this paper and cite their sources.
Full evidence
Why the trial, key points, tables, limitations, PICO, abstract, media & sources
Why the trial?
Individual randomised trials of the 0/1-hour troponin pathway were underpowered to define its safety and efficiency against standard diagnostic pathways. Pooling individual patient data across all available trials gives the most precise estimate of its effect.
Does the 0/1 h cardiac troponin pathway improve safety (30-day death or type 1 MI) and efficacy (ED length of stay and direct discharge) compared to the 0/3 h pathway in patients with suspected myocardial infarction?
View moreView less
Key Points
To assess the comparative safety and efficacy of the guideline-recommended 0/1 h pathway versus the standard 0/3 h pathway in patients presenting with suspected myocardial infarction using harmonized clinical trial data.
Systematic review and two-stage random-effects individual participant data meta-analysis (PROSPERO CRD420261383452) across PubMed, Cochrane Library, Scopus, and ICTRP through July 6, 2026.
Analyzed five randomized controlled trials comprising 110,933 patient presentations (55,489 in the 0/1 h pathway and 55,444 in the 0/3 h pathway).
Evaluated a harmonized primary safety outcome of 30-day all-cause mortality or new type 1 myocardial infarction, alongside primary efficacy outcomes of emergency department length of stay and direct discharge.
All-cause death or new type 1 myocardial infarction within 30 days occurred in 446 patient presentations (0.8%) in the 0/1 h pathway versus 562 presentations (1.0%) in the 0/3 h pathway (pooled OR 0.83, 95% CI 0.45–1.53).
Earlier cardiac troponin retesting at 1 hour did not, on average, reduce emergency department length of stay or clearly increase direct discharge rates relative to the 3-hour pathway.
Substantial between-study heterogeneity was observed, indicating that efficacy and discharge patterns vary across healthcare systems.
Evidence details
Limitations & tradeoffs
Statistical certainty
no pooled effect estimates are reported in the record; safety is described only as 'similar' without quantification.
Design limitations
record is derived from the ESC press release; the simultaneous Lancet publication is not captured in-world.
Background therapy
standard-care comparators differ across the five pooled trials.
Structured PICO
Does the 0/1 h cardiac troponin pathway improve safety (30-day death or type 1 MI) and efficacy (ED length of stay and direct discharge) compared to the 0/3 h pathway in patients with suspected myocardial infarction?
PPopulation
110,933 patient presentations with suspected myocardial infarction across five randomized trials followed for 30 days.
IIntervention
0/1 h cardiac troponin pathway (blood draws at 0 h and 1 h) for early risk stratification
CComparator
0/3 h cardiac troponin pathway (blood draws at 0 h and 3 h, i.e., standard care)
OOutcome
Composite of all-cause death or new type 1 myocardial infarction within 30 days (primary safety outcome); emergency department length of stay and direct discharge from the emergency department (primary efficacy outcomes)composite endpoint
Main Result
Odds Ratio0.83 (95% CI 0.45–1.53)
Absolute Event Rate0.8% vs 1%
Limitations
Definition of the primary safety outcome varied across trials
Emergency department length of stay was not reported for the whole analysis population in four trials
Pooled safety estimate remained imprecise
Substantial between-study heterogeneity
Definition of the primary safety outcome varied among included trials
In four trials emergency department length of stay was not reported for the whole analysis population
Expert reaction
What experts said about 0/1-hour versus standard care pathways in MI
The Lancet · ESC Congress 2026
0 experts have reacted so far. We show the split once 3 have.
Expert labels are toward 0/1-hour versus standard care pathways in MI's result, from named public quotes (n=0). As of Nov 3, 2026.
Implication
In this individual participant data meta-analysis of 5 RCTs, both 0/1 h and 0/3 h troponin pathways had low 30-day adverse event rates, but the pooled safety estimate was imprecise and the 0/1 h pathway did not on average reduce ED length of stay or clearly increase direct discharge.
Abstract
BACKGROUND: In patients with suspected myocardial infarction, the 0/1 h pathway (blood draws at 0 h and 1 h) is recommended in current guidelines for early risk stratification. However, individual trials used different safety outcomes, and efficacy outcomes were inconclusive or not assessed. We conducted a systematic review and individual participant data meta-analysis of all randomised controlled trials to synthesise the totality of the evidence, assess heterogeneity across trials, and evaluate clinically relevant outcomes using harmonised definitions across trials. METHODS: In this systematic review and individual participant data meta-analysis, we searched PubMed, Cochrane Central Register of Controlled Trials, Scopus, and the International Clinical Trials Registry Platform from inception to July 6, 2026, without language restrictions, for randomised trials comparing the safety and efficacy of 0/1 h versus 0/3 h pathways (blood draws at 0 h and 3 h, ie, standard care). Individual participant data were obtained and outcome definitions were harmonised. The primary analysis used a two-stage random-effects meta-analysis. After receipt of the individual participant data but before data harmonisation or analysis, the primary safety outcome was refined to a composite of all-cause death or new type 1 myocardial infarction within 30 days, from the originally specified composite of all-cause death or any new myocardial infarction. The primary efficacy outcomes were emergency department length of stay and direct discharge from the emergency department. This meta-analysis is registered with PROSPERO (CRD420261383452). FINDINGS: Our systematic review identified five randomised trials, all of which provided individual participant data. Among these, the definition of the primary safety outcome varied, and in four trials emergency department length of stay was not reported for the whole analysis population. We included 110 933 patient presentations (55 489 managed with the 0/1 h pathway and 55 444 managed with the 0/3 h pathway). Within 30 days, all-cause death or new type 1 myocardial infarction occurred in 446 patient presentations (0·8%) with the 0/1 h pathway versus 562 patient presentations (1·0%) with the 0/3 h pathway (random-effects pooled odds ratio [OR] 0·83 [95% CI 0·45-1·53]; I INTERPRETATION: Across the available randomised trials, short-term adverse event rates were low with both pathways, but the pooled safety estimate remained imprecise. On average, earlier cardiac troponin retesting did not reduce emergency department length of stay or clearly increase direct discharge, and substantial between-study heterogeneity indicates that treatment effects might not translate uniformly across health-care systems. For hospitals considering transitioning from a 0/3 h to a 0/1 h pathway, implementation decisions should take broader diagnostic and organisational considerations into account.
Cite This Study
Boeddinghaus et al. (2026) conducted a meta-analysis in Suspected myocardial infarction (n=110,933). 0/1 h cardiac troponin pathway (blood draws at 0 h and 1 h) vs. 0/3 h cardiac troponin pathway (blood draws at 0 h and 3 h, standard care) was evaluated on Composite of all-cause death or new type 1 myocardial infarction within 30 days (OR 0.83, 95% CI 0.45-1.53). The 0/1 h troponin pathway showed a 30-day death or type 1 MI rate of 0.8% vs 1.0% with the 0/3 h pathway (pooled OR 0.83; 95% CI 0.45-1.53).
