Professor John O’Sullivan is the inaugural Professor of Cardiometabolic Medicine at the University of Sydney and Department of Cardiology, Royal Prince Alfred Hospital. He is a Level 2 NHF Future Leader Fellow, and co-Director of the HFpEF ("Stiff Heart Failure") Clinic at RPAH. He is Director of theHeart Failure Alliance across SLHD and WSLHD, incorporating RPAH, Concord, Westmead, and Blacktown Hospitals. John is Lead Principal Investigator on two clinical trials in HFpEF: CardioNAD (ACTRN12622000340730)at RPAH, and pEFNAD (ACTRN12622000372785)across the Heart Failure Alliance, which are extensions of his discoveries in the laboratory. John is an international expert in heart failure bioenergetics, whose expertise is sought internationally by national grant bodies, in addition to medical and cardiac societies. John's clinical practice focusses on Heart Failure and Early Prevention of Atherosclerotic Cardiovascular Disease (ASCVD). John’s basic science discoveries have been translated to clinical biomarkers, Medicare Item Numbers, and new diagnostic assays.