Rationale for Research:- Heart failure (HF) is common and lethal. It is the most common diagnosis for medical admissions over 60 years of age, carries a >50% 5 year mortality and accounts for 1-2% of the total national health care budget. HF with preserved ejection fraction (HFPEF) includes over a third of HF cases presenting to New Zealand and Singapore Hospitals and has no treatment proven to reduce mortality or recurrent admissions. Renal denervation (RDN) has proven efficacy in refractory hypertension and its array of effects upon haemodynamic status, neurohumoral activity and renal function make it a rational candidate therapy in HFPEF.