Research
AI stethoscope can detect three heart conditions in 15 seconds
An AI-enabled stethoscope can help doctors pick up three heart conditions in just 15 seconds, according to the results of a real-world trial part-funded by us and presented at the European Society of Cardiology’s annual congress in Madrid.
The stethoscope, invented in 1816, is a vital part of a doctor’s toolkit, used to listen to sounds within the body. But an AI stethoscope can do much more, including analysing tiny differences in heartbeat and blood flow which are undetectable to the human ear, and taking a rapid ECG at the same time.
Researchers at Imperial College London and Imperial College Healthcare NHS Trust now have evidence an AI stethoscope can increase detection of heart failure, at the early stage when someone goes to their GP with symptoms.
1.5 million patients
A study, involving more than 200 GP surgeries, with more than 1.5 million patients, looked at people with symptoms such as breathlessness or fatigue.
Those examined using an AI stethoscope were twice as likely to be diagnosed with heart failure, compared to similar patients who were not examined using the technology.
Patients examined with the AI-stethoscope were about 3.5 times more likely to be diagnosed with atrial fibrillation – an abnormal heart rhythm which can increase the risk of having a stroke. They were almost twice as likely to receive a diagnosis of heart valve disease, which is where one or more heart valves do not work properly.
Early diagnosis
Early diagnosis is vital for all three conditions, allowing patients who may need potentially lifesaving medicines to be identified sooner, before they become dangerously unwell.
Dr Sonya Babu-Narayan, our clinical director and consultant cardiologist, said: “This is an elegant example of how the humble stethoscope, invented more than 200 years ago, can be upgraded for the 21st century.
“We need innovations like these, providing early detection of heart failure, because so often this condition is only diagnosed at an advanced stage when patients attend hospital as an emergency. Given an earlier diagnosis, people can access the treatment they need to help them live well for longer.”
Heart failure - where the heart is not pumping blood around the body properly - affects more than a million people in the UK. In more than 70 per cent of cases, it is only diagnosed after they are rushed to hospital.
But half of these people will previously have had symptoms or contact with a primary care healthcare professional, representing a potential opportunity to detect their heart failure. A smart stethoscope could help with this earlier detection.
The AI stethoscope was trialled with patients who showed any of three symptoms suggesting they were suffering from heart failure – breathlessness, fatigue or swelling of the lower legs and/or feet. If found to be at high risk, they went on to have their diagnosis confirmed with a blood test for a hormone called BNP - which is at a higher level when someone has heart failure - and a heart scan.
The stethoscope project, which was the one of the first large-scale AI research programmes to be run in British GP surgeries, saw 12,725 patients examined using the technology. These patients, within 96 surgeries in North West London, were compared to patients from another 109 surgeries in the area, where AI stethoscopes were not used.
Size of a playing card
The device, which is about the size of a playing card, is placed on a patient’s chest to take an ECG recording of the electrical signals from their heart, while its microphone records the sound of blood flowing through the heart.
This information is sent securely to the cloud – a secure online data storage area – to be analysed by AI algorithms, which have been trained on health data from tens of thousands of people and can detect subtle heart problems a human would miss. A test result, indicating whether the patient has been flagged as at-risk for heart failure or not, is sent straight back to a smartphone.
A separate algorithm can detect atrial fibrillation, which often has no symptoms and is a contributing factor to one in five strokes in the UK, but can be managed with blood-thinning medications.
People examined using AI stethoscopes were 2.33 times more likely to be diagnosed with heart failure, 3.45 times more likely to be diagnosed with atrial fibrillation, and 1.92 times more likely to be diagnosed with heart valve disease in the next 12 months.
But 70 per cent of GP surgeries given smart stethoscopes in the study stopped using them, or used them infrequently, after 12 months. The researchers suggest that efforts to integrate the technology into GPs’ existing routines would be needed to roll the technology out more widely.
The study showed two-thirds of people identified by the AI stethoscope as having suspected heart failure did not in fact have it, when given a further blood test or heart scan.
That could lead to unnecessary anxiety and tests for some people, but researchers point out that for other patients, using the AI stethoscope could detect signs of heart failure which might otherwise have been missed. The researchers stress that the AI-stethoscope should be used for patients with symptoms of suspected heart problems, and not for routine checks in healthy people.
Already available
Professor Nicholas Peters, senior investigator from Imperial College London and consultant cardiologist at Imperial College Healthcare NHS Trust, said: “Our study shows that three heart conditions can now be identified in one sitting.
“Importantly, this technology is already available to some patients and being widely used in GP surgeries.”
The researchers next plan to roll out the technology to GP practices in Wales, South London and Sussex.
The study, called TRICORDER, was funded by the us, the National Institute for Health and Care Research (NIHR) and Imperial Health Charity, and supported by the NIHR Imperial Biomedical Research Centre.
The researchers supplied GP practices with an AI stethoscope manufactured by Californian company Eko Health.