St Emlyn’s Lesson Plans

Journal club: LoDED and safe early discharge

Appraise the LoDED diagnostic-strategy trial and discuss what would be needed to apply its findings locally.

Higher Specialty Training · 60-minute session

For learners

Before: Allow about 28 minutes in total.

When we meet: We will discuss what the trial tested, the uncertainty in its results and the effect of local assays and care pathways.

After: choose a point to follow up in practice

For facilitators

Send: the learner preparation link before teaching.

Bring: Trial tables, local chest-pain pathway, calculator and whiteboard divided into accuracy, effectiveness and implementation.

Run: 60-minute session plan · 30-minute option

Before the session

If you are attending this session, complete the core preparation below before you come. Allow about 28 minutes in total.

Core preparation

LoDED trial, Heart 2020 · About 20 minutes

Read the completed 2020 trial's eligibility criteria, intervention, usual-care description and main results.

https://doi.org/10.1136/heartjnl-2020-316692

NICE HTG552: High-sensitivity troponin tests · About 5 minutes

Read the recommendations for using high-sensitivity troponin in early NSTEMI rule-out. The facilitator will confirm the local assay and sampling pathway.

https://www.nice.org.uk/guidance/htg552

Think about (allow 3 minutes): What makes an undetectable troponin result different from a complete discharge decision?

Picture the scene

A patient with apparently low-risk chest pain has one undetectable high-sensitivity troponin result. What else would you need before deciding whether they can leave?

By the end of the session

Distinguish a strategy trial from a diagnostic-accuracy study and choose appropriate appraisal questions.
Interpret the trial’s early-discharge outcome and uncertainty without claiming zero future risk.
Identify the assay, patient selection and system requirements before applying a pathway locally.

After the session

Find one instance where “negative troponin” appears in your documentation; replace it with a clear statement of the pathway result and remaining clinical assessment.

Optional further learning

You do not need to complete this before attending. The listening time is additional to the core preparation above.

Optional listening · 27 min 19 sec

St Emlyn’s Podcast: Ep 167 - Troponin Update and LoDED Study Review with Rick Body

Hear an investigator’s interpretation of LoDED and compare it with your own appraisal.

Listen to the episode

Search for this episode by title in MedPod Learn if you want to record your listening there.

After reading the paper, compare one claim in this 2020 interview with the trial’s population, outcome and limitations. Its draft NICE/CQUIN links are historical; consult the current NICE guidance and local assay pathway.

https://www.stemlynspodcast.org/e/troponin-update-and-loded-study-review-with-rick-body/

Facilitator guide

Send learners the preparation link several days before teaching. Allow about 28 minutes in total.

Before learners arrive

Read the completed trial and check the reported counts and confidence interval before showing the exercise.
Ask the laboratory or pathway lead to confirm the current assay, reporting units, thresholds and approved sampling times. If unknown, make that a recorded implementation question rather than guessing.

Equipment: Trial tables, local chest-pain pathway, calculator and whiteboard divided into accuracy, effectiveness and implementation.

Setup: Assign pairs to methods, results and transferability. Invite different interpretations of the same interval and ask what assumption explains the difference.

If the preparation has not been completed

Within the ten-minute methods slot, use eight minutes to read the abstract and intervention definition, followed by two minutes for pairs to state the selection rules and what randomisation compared. Point out the requirement concerning ongoing clinical concern. In the 30-minute version, use two minutes for the clinical question and eight for this shared preparation; retain 12 minutes for results, six for local application and two for closing.

Suggested session plan

0–5 min — State the decision. Ask what an undetectable result does not tell us.
5–15 min — What the strategy included. Make the group name every intervention component and the comparator.
15–33 min — Interpret the results. Explore effect size, uncertainty and rare safety outcomes.
33–45 min — System and assay differences. Compare the study with actual local practice without inventing missing facts.
45–55 min — Implementation proposal. Write a short plan for evidence review and monitoring, not an immediate clinical policy change.
55–60 min — Close. Each learner states the most important qualification to the headline conclusion.

Start the discussion

Read the opening scenario together. Give everyone a moment to think, then ask what concerns them and what they need to know next.

Cases and discussion

Use these cases, or invite an anonymised case from the group that addresses the same questions.

An undetectable result at the bedside

A 48-year-old has chest discomfort, a non-ischaemic ECG and an undetectable initial hs-troponin. Pain has settled. The local department uses a different assay and pathway from the one a colleague remembers from a podcast.

Add this information as the discussion develops:

Ask learners to state the discharge rule they think the paper tested.
Reveal that peak symptoms were recent and the clinician remains concerned about the character of the pain.
Ask the group to distinguish a trial eligibility discussion from a decision to discharge this individual.

Ask the group:

What else was required in the intervention besides an undetectable result?
What does the trial tell us about NSTEMI, and what other causes of chest pain remain?
Why do the assay’s limit of detection and reporting convention matter?
Who has authority to change a departmental rule-out pathway?

Discussion notes

Points to draw out:

LoDED was an open-label randomised strategy trial with blinded endpoint assessment across eight hospitals, not simply a sensitivity/specificity study. Its rule included a non-ischaemic ECG, assay-undetectable hs-troponin and no ongoing clinical concern.
Clinical application requires an approved local assay-specific pathway and a full clinical assessment.
A myocardial-infarction rule-out result does not diagnose the pain or exclude every serious cardiac and non-cardiac condition.

Common misconceptions:

Treating “negative” as a universal laboratory threshold.
Replacing the clinician’s concern with a mechanistic reading of one result.

For a more experienced group: Ask the group to describe what evidence the laboratory and cardiology teams would need before adopting a new assay or threshold.

Did the strategy improve care?

Early discharge without 30-day MACE occurred in 141/309 (46%) with LoDED and 114/311 (37%) with usual care; pooled adjusted OR 1.58, 95% CI 0.84–2.98.

Add this information as the discussion develops:

Ask pairs to give a plain-language interpretation before discussing statistical significance.
Reveal that usual-care pathways varied by centre and that early discharge in the control group was higher than anticipated in the sample-size assumptions.
A colleague says no events among those with undetectable initial troponin proves the strategy is perfectly safe.

Ask the group:

What is the unit of intervention: a test, threshold, clinician or care pathway?
Which effects are compatible with the confidence interval?
How can an efficient usual-care pathway reduce the apparent benefit of a new strategy?
What can an absence of observed events establish in a finite sample?
Which patient-centred and service outcomes would you also want?

Discussion notes

Points to draw out:

The point estimate favours earlier discharge, but the adjusted interval includes no difference and a range of possible effects. Avoid claiming a definitively superior overall strategy from this result alone.
Observed zero events is reassuring within the study but cannot prove zero risk. Applicability depends on selection, follow-up and the uncertainty around rare outcomes.
Process outcomes are affected by staffing, laboratory turnaround and downstream decisions. A pathway may be diagnostically sound yet fail to shorten stay in a specific system.

Common misconceptions:

Treating an odds ratio as an absolute increase in discharge probability.
Applying a diagnostic-accuracy checklist without assessing randomisation, contamination or usual-care differences.

For a more experienced group: Sketch a local implementation evaluation including balancing measures, protocol deviations, return visits and patient understanding.

Important clinical points

Use current locally approved assay-specific thresholds and timing.
Persistent clinical concern or an alternative serious diagnosis requires assessment beyond a troponin rule-out.

Closing the session

Use these questions to check what the group will take away. Go back over any clinical points that remain unclear.

Why is this not simply a diagnostic-accuracy study?
What does the confidence interval leave uncertain?
How would you challenge a zero-risk claim?
What would you check before changing practice?

Key teaching points:

Use appraisal questions suited to a randomised strategy trial.
The LoDED strategy included an ECG, an assay-specific result and assessment of ongoing clinical concern.
Laboratory turnaround, usual care and discharge processes can affect whether a strategy shortens stay.

Before leaving, ask each person to choose one action from After the session and say when they will try it. They complete that follow-up in practice, with supervision where needed.

Adapting the discussion

Uncertainty and local practice

Rare-event safety cannot be proven absolutely by one trial. The session supports critical application of evidence; it does not authorise bypassing the current local pathway.

If the discussion drifts

Are we discussing accuracy, clinical effectiveness or implementation, and which data answer that question?

For a more experienced group

Explore centre heterogeneity, changing usual care and the relation between a diagnostic cohort study and a randomised strategy trial.

A 30-minute version

30-minute option: question 3, methods 7, results 12, local application 6, closing 2. Omit the full implementation exercise.

Evidence and guidance

LoDED trial, Heart 2020 — Completed randomised strategy trial; use this results paper for the appraisal.https://doi.org/10.1136/heartjnl-2020-316692
NICE HTG552: High-sensitivity troponin tests — Assay-specific guidance for early NSTEMI rule-out, previously published as DG40.https://www.nice.org.uk/guidance/htg552