Myocardial Perfusion, Oxidative Metabolism, and Fibrosis in HFpEF

The investigators hypothesize that HFpEF is associated with reductions in myocardial blood flow and energy utilization and increased myocardial fibrosis as compared to age and gender matched hypertensive and healthy controls. The investigators will test their hypotheses by comparing measurements of myocardial blood flow, energy utilization, and fibrosis between three subject groups (HFpEF vs hypertension vs healthy). Myocardial blood flow will be quantitated from nitrogen (N)13-Ammonia positron emission tomography (PET) and gadolinium enhanced cardiac magnetic resonance (CMR) imaging, both at rest and stress following coronary vasodilation with regadenoson. Myocardial energy utilization will be quantified with 11C-acetate PET imaging and myocardial fibrosis will be assessed with gadolinium enhanced CMR and alterations in myocardial T1. Echocardiography will be utilized to quantify cardiac diastolic function. It is anticipated that the results of this proposed study will provide a foundation that will inform future studies aimed at identifying novel preventive or therapeutic agents in HFpEF.