A cutting-edge cardiac test creates a 3D model of the heart’s arteries to help physicians understand patient risk, in an innovation that is improving care for people with suspected coronary artery disease
Using technology for better heart care
‘In the old days, the approach was “If it looks blocked, open it up.” In modern coronary intervention, we know this isn’t best practice.’ For Dr Joban Sehmi, cardiology consultant at West Hertfordshire Hospitals NHS Trust, the HeartFlow Analysis – a digital tool that creates a 3D model of coronary arteries and models blood flows – is enabling him to diagnose patients non-invasively and quickly.
For people with suspected coronary artery disease – where build-up in the arteries causes narrowing or blockages – the diagnosis process can be lengthy and invasive. An initial CT scan can quickly give some patients the all clear and identify those with severe disease. But for those in between, the results are less clear and take much longer.
‘Our patients with moderate disease were having to wait several weeks for further testing,’ explains Joban. In his institution, these patients were given a stress echo test, which involves patients exercising or receiving drugs to increase their heart rate, while an ultrasound scan is performed before, during and after stress. ‘The long wait for this test caused considerable anxiety, even though only 10 percent would need further treatment.’ So when Joban heard about the HeartFlow Analysis, his interest was piqued.
The HeartFlow Analysis is a digital tool that uses standard CT scans to create a 3D model of each person’s heart, and computes blood flow characteristics in the arteries of the model. Physicians can use the model to assess the impact of each blockage on the blood’s ability to reach the heart. Developed using computational fluid dynamics and artificial intelligence techniques, it draws on algorithms based on data from thousands of patients to predict the probable impact of different patterns of blockages.
NHS England named HeartFlow as one of the products available to NHS providers through its Innovation and Technology Payment (ITP) programme in April 2018. This programme is designed to remove financial and procurement barriers to innovation, supplying ITP products at zero cost to providers. As a result, Joban was able to start using HeartFlow.
‘HeartFlow allows a comprehensive assessment of the heart, usually within hours,’ he explains. ‘Most of our patients will receive letters within a few days reassuring them that all is well, and we can quickly get the others started on treatment or directed towards downstream testing.’
The HeartFlow Analysis allows doctors to plan coronary stenting in patients who will benefit most. This procedure involves passing a long tube through an artery in the wrist or groin up into the heart. Dye is injected and x-rays taken to image the blood vessels on the surface of the heart. Where a blockage is identified, a balloon is inflated and a mesh or strut is implanted to keep the artery open. These procedures are minimally invasive and life-saving, Joban emphasises, but they are not without risk, and should be focused on the right patients.
‘No test is perfect,’ he adds, ‘and we have to accept that. We’ve questioned some of the information we’ve received from HeartFlow. Where there is disagreement between the HeartFlow Analysis and clinical findings, a detailed investigation is carried out in effort to improve the product. I’ve been very impressed.’
Running the test in a one-stop clinic drastically simplifies the patient pathway. For patients, that means getting all the information they need at one time, fewer days off for hospital appointments, and reduced referral-to-treatment time, leading to improved satisfaction. But there are important organisational benefits too, says Joban: ‘Referrals to the stress echo department have reduced, so they can focus their resources on other types of patients. It’s been a very positive experience.’