§ Claim under review · Research
"Imperial College London researchers built an AI model that can detect heart failure and valve disease from a routine ECG in under two seconds, trained on 10.6 million ECGs and tested on 65,000 patients, correctly flagging heart failure in 81% of cases and valve disease in 90%, with a 590-patient trial starting at six hospitals ahead of a possible NHS rollout within two years."
Verdict
Source exists but framing is misleading
Confidence
MediumSummary
This post describes real research, but its two headline accuracy numbers are presented in a way that overstates the results. Imperial College London researchers did present an AI ECG tool at the European Society of Cardiology congress in Munich in late August 2026, trained on 10.6 million ECGs and tested on more than 65,000 US patients, and a 590 patient NHS study is genuinely running across six hospitals in London and Bristol. However, the 81 percent and 90 percent figures come from two different test groups, not one. In the large group of 61,520 patients the tool caught 81 percent of weak heart pumping cases but only 80 percent of aortic stenosis cases, and the 90 percent valve figure comes from the much smaller group of 5,442 patients. The 90 percent also refers specifically to aortic stenosis rather than valve disease in general, and the funder's own wording says "up to" 81 and 90 percent, a hedge the post drops. The researchers stress the tool cannot diagnose on its own and is meant to move high risk patients up the queue for an ultrasound scan. The findings were presented at a conference and have not yet appeared in a peer reviewed paper, and key figures such as the false positive rate have not been published.
The readings
key figures from the evidencereduced pumping function detected, large 61,520-patient cohort
aortic stenosis detected, small 5,442-patient cohort
aortic stenosis discrimination, large 61,520-patient cohort
Why this verdict
Evidence
The underlying work is real, recent, and from the named team. Artificial intelligence could find signs of heart failure and heart valve disease in a routine ECG, according to research funded by the British Heart Foundation, led by Imperial College London and presented at the European Society of Cardiology Congress in Munich . ESC Congress 2026 took place in Munich and online from 28 to 31 August 2026 .
On training: to develop the AI, researchers gave it 10.6 million ECGs together with the clinical reports describing them, and the model was then trained to learn the connection between the patterns in the ECG results and specific heart conditions, using 72,475 ECGs linked to scan results revealing the structure and function of the heart .
On testing: the technology was tested on the ECGs of a small group of 5,442 patients in the US, and the ECGs of a larger group of 61,520 US patients, whose echocardiogram results could be compared with the AI analysis .
The cohort-level breakdown is where the claim's two headline percentages come apart. Researchers tested whether the AI could identify reduced left ventricular ejection fraction, as well as thickening of the heart muscle, and heart valve disease of moderate severity or higher.
It correctly identified 77 per cent of the small group of 5,442 patients, and 81 per cent of the large group of 61,520 patients who had poor heart pumping function. For valve disease, the AI was able to identify several forms of heart valve disease, although its performance varied depending on which valve was affected. For aortic stenosis, the AI correctly identified 90 per cent of the small group of more than 5,000 patients, and 80 per cent of the larger group of more than 61,000 patients, who had aortic stenosis.
For reduced heart pumping function, the AI achieved an area under the receiver operating characteristic curve of 0.86 for the set of 5,442 patients, and 0.9 for the larger group. For aortic stenosis, it achieved a score of 0.85 and 0.73, respectively.
The researchers themselves scope the tool as triage rather than diagnosis. The technology cannot be used on its own to definitively diagnose or rule out heart failure or heart valve disease, but it gives a strong indication that someone may have these conditions from their ECG. Someone judged as high-risk could be sent rapidly for an ultrasound heart scan called an echocardiogram, if this technology became available in the future.
On the NHS study: the AI is now being tested on ECGs from 590 NHS patients across London and Bristol, and the team say the AI ECG technology could be two years away from being used routinely for patients . The NHS trial will recruit patients who are being treated at Chelsea and Westminster Hospital, West Middlesex University Hospital and Hammersmith and St Mary's hospitals, in London, as well as Bristol Royal Infirmary and Southmead Hospital in Bristol. That is six named hospitals. The corresponding registry entry, NCT07057466, "Prospective Evaluation of Artificial Intelligence-enhanced Electrocardiography for Detection of Structural Heart Disease" (AI-ECG-SHD), sponsored by Imperial College London, is listed as RECRUITING with an actual start date of 4 November 2025 and an estimated primary completion date of 3 May 2027 , and it lists five recruiting UK sites: Southmead Hospital in Bristol, and Chelsea and Westminster, Hammersmith, St Mary's and West Middlesex University hospitals in London , with El-Medany as contact.
Context on the team and the commercial vehicle: the work, led by Professor Fu Siong Ng's group, is being taken forward into a spinout company called Cardiovolt.ai .
Findings
✓ What's accurate 8
- Imperial College London researchers, with Chelsea and Westminster Hospital NHS Foundation Trust and BHF funding, did present this work at ESC Congress 2026 in Munich.
- The "under two seconds" read time is what the funder and the researchers state.
- The 10.6 million ECG training figure is accurate as the general training corpus.
- The test set size is accurate: more than 65,000 US hospital patients across two cohorts (5,442 plus 61,520).
- 81% is a real reported figure: detection of reduced heart pumping function in the 61,520-patient cohort.
- 90% is a real reported figure: detection of aortic stenosis in the 5,442-patient cohort.
- The 590-patient NHS study is real, is registered, and is running across six named hospitals in London and Bristol.
- "Possible NHS rollout within two years" faithfully reflects the team's own stated estimate, and the claim correctly hedges it with "possible."
≈ What's misleading 5
- **Benchmark cherry picking:** The claim pairs 81% and 90% as if they were the model's two results on one test population. They are the best figure from each of two different cohorts. In the large 61,520-patient cohort the model detected 81% of reduced pumping function but only 80% of aortic stenosis; in the small 5,442-patient cohort it detected 90% of aortic stenosis but only 77% of reduced pumping function. No single cohort produced the 81/90 pairing the claim presents.
- **Omitted qualifier:** The funder's own wording is "up to 81 per cent" and "up to 90 per cent." Dropping "up to" converts a ceiling into a typical result. The claim also omits that the 90% aortic stenosis figure sits alongside an AUROC of 0.73 in the larger cohort, which is a substantially weaker discrimination result than the headline percentage implies.
- **Capability extrapolation:** "Valve disease in 90%" generalises a result specific to aortic stenosis. The funder states performance varied by which valve was affected, and only the aortic stenosis numbers were given. The claim presents one valve lesion's best number as covering valve disease as a category.
- **Demo to product conflation (mild):** "Can detect heart failure and valve disease" reads as diagnosis. The researchers state the tool cannot on its own diagnose or rule out either condition and is intended to prioritise patients for an echocardiogram. The claim's word "flagging" partly preserves this, but the opening phrase "can detect" does not.
- **Cost compute omission, applied to evidence rather than compute:** Only detection rates are quoted. Specificity, positive predictive value, and the operating thresholds are not in any source found. A detection rate quoted without its false-positive rate cannot tell a reader how useful the tool is in practice, and this omission runs through the claim and its upstream coverage alike. A note on origin: most of these distortions are already present in the mainstream coverage chain, and the Instagram post largely inherits rather than invents them. The post's own contribution is dropping the "up to" hedges and compressing two cohorts into one.
? What's uncertain 7
- The ESC abstract itself, and any preprint or peer-reviewed paper, could not be located. All performance figures trace to the funder's news release and press coverage of a conference talk, not to a retrievable primary research artifact.
- Specificity, PPV, false-positive rates, thresholds, and confidence intervals are not published in any source found, so the practical screening yield cannot be assessed.
- The exact model name and version presented at ESC could not be pinned. The claim is version-ambiguous, which caps confidence.
- The 590 enrolment target is reported by BHF and the NHS trust but was not confirmed against the registry's enrolment field.
- The registry lists five recruiting sites; the NHS trust release names six hospitals. Bristol Royal Infirmary may not yet be open to recruitment.
- "Trial starting" is slightly off: the registered study has an actual start date of 4 November 2025 and is already recruiting.
- No independent evaluation of this specific model on these tasks was found.
Sources
6 of 7 linked to recordsClinicalTrials.gov record NCT07057466, "Prospective Evaluation of Artificial Intelligence-enhanced Electrocardiography for Detection of Structural Heart Disease" (AI-ECG-SHD), sponsor Imperial College London, status RECRUITING, actual start 2025-11-04, contact Dr Ahmed El-Medany
British Heart Foundation news release, "AI finds hidden heart disease in under two seconds" (September 2026), the study's funder reporting cohort-by-cohort detection rates and AUROC values
Chelsea and Westminster Hospital NHS Foundation Trust news release naming the six trial sites
European Society of Cardiology press materials confirming ESC Congress 2026 was held in Munich, 28 to 31 August 2026
Health Research Authority research summary, "Prospective evaluation of AI-ECG for SHD detection"
Imperial College London news item on the Cardiovolt.ai spinout from Professor Fu Siong Ng's group
Syndicated reproductions of Guardian and PA coverage of the ESC presentation (Dataconomy, News Beep, Archynewsy, Mugglehead)