Doctors at the University of East Anglia have developed a new method that could change how heart failure is assessed, using a standard MRI scan instead of an invasive procedure. Heart failure patients often undergo right heart catheterisation, where a tube is inserted into the heart to measure blood oxygen levels, which helps determine the severity of their condition. However, this procedure can be risky, especially for older or frail individuals.
In collaboration with researchers from the University of Leeds and Newcastle University, the team created a way to estimate blood oxygen levels using cardiac MRI scans. The method uses T2 mapping, a common MRI measurement, to estimate how much oxygen remains in blood returning to the heart—a key indicator of heart function.
Prof Garg explained: "Blood with different oxygen levels behaves slightly differently in a magnetic field. By measuring how that blood reacts, we were able to develop a formula that predicts the oxygen reading without ever inserting a tube or taking a blood sample."
The technique was first tested on 30 patients and showed results similar to those from traditional catheter tests. Researchers then applied it to 628 people recently diagnosed with heart failure and followed them for about three years. Patients with healthier MRI-based oxygen readings were less likely to die or be hospitalized due to their condition. The accuracy of this MRI-based assessment remained consistent even when considering factors like age and other health issues.
Prof Garg stated: "One of the most important markers in advanced heart failure is how much oxygen is left in blood returning to the right side of the heart. Until now, getting that number has usually meant a tube test. Our study shows it can be estimated non-invasively from a standard heart MRI."
Dr Peter Swoboda from the University of Leeds said: "This means we may be able to read off a crucial haemodynamic number from an everyday scan - effectively turning a routine MRI into a much more powerful test, without putting a tube into the heart."
Dr Gareth Matthews from the University of East Anglia added: "Because this can be done as part of a standard cardiac MRI, it needs no extra hardware and no contrast dye, and adds only seconds to the scan.
"It has real potential to widen access to safer heart failure assessment across the NHS," he said.
The research team noted that further studies are needed in different hospitals and patient groups before widespread adoption. Their findings appear in JACC Advances under 'Development and validation of a non-invasive model of mixed venous oxygen saturation in heart failure'.
