Smartphone AI Assistance for Prehospital ECG Interpretation (ECG-IA)

September 4, 2026 updated by: Laurent Bourgeois, École Supérieure de Soins Ambulanciers - College of Higher Education in Prehospital Care

AI & Prehospital ECG Analysis: A Randomized Controlled Trial of a Smartphone Large Language Model for Occlusion Myocardial Infarction Detection by Prehospital Providers

Prehospital providers interpret 12-lead electrocardiograms (ECGs) under time pressure and without immediate expert support. Missed acute coronary occlusion - occlusion myocardial infarction (OMI) - delays reperfusion, while false positive interpretations trigger unnecessary catheterization laboratory activations. Multimodal large language models (LLMs) available on any smartphone can now analyze a photographed ECG, and prehospital providers have begun using them spontaneously. No randomized trial has evaluated whether this practice improves diagnostic performance.

This randomized controlled trial compares the diagnostic performance of prehospital providers interpreting ECG clinical vignettes with and without mandatory assistance from a single, version-locked smartphone large language model. Participants - paramedics, emergency medical technicians, nurses and physicians practicing in prehospital care in French-speaking Switzerland - are randomized 1:1 on a dedicated digital platform and answer 14 clinical vignettes presented in individually randomized order. Each vignette is built around a real, anonymized 12-lead ECG obtained during routine clinical care.

The primary outcome is the proportion of vignettes for which the participant correctly identifies the presence or absence of an OMI. Secondary outcomes are sensitivity, specificity, and the accuracy of the prehospital priority decision level.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Design and setting. Two-arm parallel-group randomized controlled trial conducted on a dedicated digital platform. Phase 1 takes place during a single in-person session at the Swiss French-speaking prehospital clinical research conference (Morat, Switzerland, 2 September 2026). Phase 2 extends recruitment to prehospital emergency services across French-speaking Switzerland (September to November 2026) using an identical standardized protocol.

Randomization. Individual 1:1 allocation performed automatically by the platform using permuted blocks of variable size (4 to 6), without stratification, after the demographic questionnaire and before the first vignette. Allocation cannot be changed once assigned. The presentation order of the 14 vignettes is independently randomized for each participant, which neutralizes position effects and prevents copying between neighbouring participants.

Intervention. Participants allocated to the intervention arm must consult the study-imposed large language model for every vignette before submitting their answer; the platform locks the submit button until use of the tool is confirmed. A single model (OpenAI GPT-4o) in an API version locked for the entire study is used by all participants, with a standardized, non-modifiable prompt identical for every participant and every vignette. Participants cannot add text, ask follow-up questions, or provide additional clinical context. Exposure to the tool is mandatory, but adherence to its interpretation is not: participants remain free to base their final answer on their own clinical reasoning. Control participants interpret the same ECGs unaided, with smartphones turned face down and out of reach.

Reference standard. For each vignette, the expected answers were defined a priori by the study cardiologist and locked, with any subsequent modification time-stamped in the platform audit log. The reference standard is the answer expected of a prehospital provider at the point of care, anchored on coronary angiography wherever angiography is discriminant. For non-ischaemic mimics, the expected answer depends on whether the acute presentation allows the condition to be distinguished from a coronary occlusion: it does not for the Takotsubo case included in the study, whose expected answer is therefore "yes", whereas acute pericarditis, being usually recognizable, has an expected answer of "no". This pre-specified departure from a purely angiographic standard is reported as such, and the primary analysis is repeated in a sensitivity analysis in which all mimics are classified as non-OMI.

Blinding. Participants and investigators cannot be masked. The statistician conducting the primary analysis receives coded group labels only, and the allocation key is released after database lock and approval of the statistical analysis plan.

Statistical analysis. Mixed-effects logistic regression with correct OMI identification at vignette level as the dependent variable, arm as the main fixed effect, grouped ECG category as a fixed covariate, and random intercepts for participant and for vignette. Intention-to-treat, alpha 0.05 two-sided. The target is 130 evaluable participants (65 per arm), giving 80% power to detect an absolute increase from 0.65 to 0.80 with an intraclass correlation up to approximately 0.43. Allowing for approximately 10% of sessions to be abandoned before completion, planned enrollment is 144 (72 per arm).

ECG material. All tracings originate from routine clinical care at the Geneva University Hospitals, were selected by a cardiologist to cover predefined electrocardiographic categories, and were anonymized at source before transmission to the research team. No patient is enrolled, followed or contacted, and the research team holds no key allowing re-identification.

Pilot. A technical pilot involving a small number of prehospital providers was conducted before the study start date to test the platform. Pilot sessions took place outside the standardized study conditions and are identified in the database by a dedicated centre code; their data are excluded from all analyses, as pre-specified in the protocol.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
144

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Switzerland
    • Canton of Fribourg
      • Murten/Morat, Canton of Fribourg, Switzerland, 3280
        • Recruiting
        • Caserne des pompiers de Morat (Swiss French-speaking prehospital clinical research conference)
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Prehospital care provider practising in French-speaking Switzerland
  • Any level of training: emergency medical technician, paramedic (ES), nurse (ES/HES) in prehospital emergency care, or prehospital emergency physician
  • Electronic informed consent signed before randomization

Exclusion Criteria:

  • Cardiologist
  • Any person not practising in prehospital care
  • Insufficient command of written French to answer the vignettes reliably
  • Refusal to participate or withdrawal of consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
No Intervention: Control: unaided ECG interpretation
Participants interpret each of the 14 ECG vignettes without any assistance. Smartphones are turned face down and out of reach for the duration of the session. No intervention is administered.
Experimental: AI-assisted ECG interpretation
Participants must consult the study-imposed large language model for every vignette before submitting their answer. The platform locks the submit button until use of the tool is confirmed. Participants remain free not to follow the interpretation produced by the model and may base their final answer on their own clinical reasoning.
Diagnostic test: Smartphone large language model assistance (GPT-4o, version-locked)
The platform transmits the ECG image to a single large language model (OpenAI GPT-4o, API snapshot gpt-4o-2024-08-06), locked for the entire study, together with a standardised prompt identical for all participants and all vignettes: "I am on an urgent prehospital call with a patient who presents this ECG. Analyse it and tell me what you think." Participants cannot modify the prompt, ask follow-up questions or provide additional clinical context. The model version and system fingerprint returned by the API are recorded for every call. The model's interpretation is displayed within the vignette. Use of the tool is mandatory; adherence to its interpretation is not.
Other Names:
  • ChatGPT
  • gpt-4o-2024-08-06

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Proportion of vignettes with correct identification of occlusion myocardial infarction (OMI) status
Time Frame: Single study session, approximately 90 minutes; 14 vignettes per participant
For each of the 14 vignettes, the participant answers a binary question: "At this stage of care, is an OMI (acute coronary occlusion) likely? Yes / No". Responses are scored against a reference standard defined a priori, vignette by vignette, by the study cardiologist and locked before data collection. This reference standard is the answer expected of a prehospital provider at the point of care, anchored on coronary angiography wherever angiography is discriminant. For non-ischaemic mimics the expected answer depends on whether the acute presentation allows the condition to be distinguished from a coronary occlusion: it does not for the Takotsubo case (expected answer "yes"), whereas acute pericarditis is usually recognisable (expected answer "no"). This pre-specified departure from a purely angiographic standard is reported as such, and the analysis is repeated in a sensitivity analysis classifying all mimics as non-OMI. The outcome is the proportion of correctly classified vignettes
Single study session, approximately 90 minutes; 14 vignettes per participant

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Sensitivity of OMI detection
Time Frame: Single study session, approximately 90 minutes
Proportion of correctly identified OMI among vignettes whose expected answer is "yes", compared between arms. Analysed by mixed-effects logistic regression restricted to these vignettes, with arm as fixed effect and a random intercept per participant.
Single study session, approximately 90 minutes
Specificity of OMI detection
Time Frame: Single study session, approximately 90 minutes
Proportion of correctly identified non-OMI among vignettes whose expected answer is "no" (non-occlusive ischaemia, indeterminate ischaemia, recognisable non-ischaemic mimics, normal or non-specific ECGs), compared between arms. Same modelling approach as for sensitivity.
Single study session, approximately 90 minutes
Accuracy of the prehospital priority decision level
Time Frame: Single study session, approximately 90 minutes
Proportion of vignettes for which the participant selects the correct prehospital priority decision level, on a pre-specified five-level scale ranging from high-risk acute coronary syndrome with activation of the STEMI pathway to clearly non-cardiac symptoms. The expected level is defined a priori for each vignette and locked before data collection.
Single study session, approximately 90 minutes

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Diagnostic accuracy on the closed-list diagnosis question
Time Frame: Single study session, approximately 90 minutes
For each vignette the participant selects a single diagnosis from a closed list of 86 items grouped in 8 families, using a filterable selector. Two variables are produced automatically: exact match with the expected diagnosis, and match with the expected diagnosis or with any diagnosis pre-specified as clinically acceptable. Reported descriptively by ECG category and by arm, then modelled by mixed-effects logistic regression if numbers allow. The primary analysis uses the exact-or-acceptable variable; the strict variable is reported as a sensitivity analysis.
Single study session, approximately 90 minutes
Self-reported confidence and calibration
Time Frame: Single study session, approximately 90 minutes
Confidence in the answer is reported by the participant for each vignette on a five-point Likert scale of self-reported diagnostic confidence, ranging from 1 (not at all confident) to 5 (very confident). A higher score indicates greater self-reported confidence; confidence is a descriptive measure and a higher score is not in itself a better outcome. Confidence is compared between arms by mixed-effects ordinal logistic regression. Calibration is assessed as the concordance between reported confidence and the actual correctness of the answer, using calibration curves and the Brier score, which ranges from 0 to 1, a lower score indicating better calibration.
Single study session, approximately 90 minutes
Self-reported influence of the AI on the final answer
Time Frame: Single study session, approximately 90 minutes
Degree to which the participant reports having been influenced by the model's interpretation, on a five-point Likert scale, collected for each vignette in the intervention arm only. Analysed descriptively and in relation to the correctness of the answer. No comparison between AI tools is conducted, the model version being fixed.
Single study session, approximately 90 minutes
Response time per vignette
Time Frame: Single study session, approximately 90 minutes
Time from display of the vignette to submission of the answer, measured automatically in seconds by the platform. Analysed by linear mixed-effects model on the log of the response time, with arm as fixed effect and a random intercept per participant; a sensitivity analysis compares individual median times between arms. A longer time is expected in the intervention arm owing to consultation of the model, and is treated as a feasibility outcome for prehospital use.
Single study session, approximately 90 minutes
Diagnostic performance by level of training
Time Frame: Single study session, approximately 90 minutes
Diagnostic performance according to the participant's level of training (emergency medical technician, paramedic, nurse, physician), and interaction between arm and level of training. The study is not powered for this comparison and the distribution of training levels depends on spontaneous recruitment; results are hypothesis-generating and reported with confidence intervals only. A minimum of 10 participants per category is required for separate analysis, failing which categories are pooled according to a rule documented before unblinding.
Single study session, approximately 90 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
École Supérieure de Soins Ambulanciers - College of Higher Education in Prehospital Care

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University Hospital, Geneva
Swissrescue.ch, Website for Prehospital Healthcare Providers, Les Pontins, Switzerland

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 2, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 27, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 4, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 9, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ECG-IA-2026
  • 2026-01430 (Other Identifier: Cantonal Research Ethics Committee of Geneva (CCER) - BASEC)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Fully anonymised individual participant data - responses to all vignettes, demographic variables and platform-generated technical variables - will be deposited in an open repository (Zenodo or OSF) at the time of publication, in accordance with FAIR principles. The ECG tracings themselves are excluded from this deposit: they originate from routine clinical care at the Geneva University Hospitals, which authorise their use for this study only and do not permit transmission to third parties. Requests concerning the tracings must be addressed to the Geneva University Hospitals.

IPD Sharing Time Frame

From the date of publication, with no end date.

IPD Sharing Access Criteria

Open access, no restriction, no request procedure.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings