Patients of heart failure are required to undergo a ‘right heart catheterisation’ test, in which a tube is inserted in the heart to measure oxygen levels in the blood — this helps doctors understand the severity of the condition. Nearly 630 people newly diagnosed with heart failure were then analysed using the MRI method and were followed for around three years. “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. Our study shows it can be estimated non-invasively from a standard heart MRI,” Dr Garg said. “Our breakthrough could be a game changer for assessing advanced heart failure.