Design and Methods:- Renal denervation will be tested as a therapy for HFPEF in a multi-centre open, randomized controlled trial of bilateral renal artery denervation compared with ongoing medical management. Sample size (n=144) will be sufficient to provide 90% power to detect clinically relevant effects on the primary endpoints of change in left atrial volume and left ventricular mass over 6 months post-RDN. Secondary end-points will include assessment of exercise capacity, ventricular-vascular coupling, biomarkers (of cardiac haemodynamic load, fibrosis, inflammation and cardiomyocyte loss), quality of life and cardiovascular events.