In this study the investigators are aiming to recruit 130 patients with heart failure with preserved ejection fraction who are obese and non-obese to undergo CT and MRI scans, as well as some other investigations including blood tests, to help investigate if having more fat around the heart leads to worse heart function in this condition. This may lead to the development of new treatments aimed at lowering fat levels around the heart and in the rest of the body, specifically to treat HFpEF.