Prevalence and Prediction of ATTR in Ambulatory Patients With HFpEF

Patients 65-years and older with HFpEF will be enrolled to participate in this single center, event driven (positive nuclear amyloid scan also known as 99mTc-pyrophosphate SPECT scan) study. During the single study visit the following will be obtained: * 99mTc-pyrophosphate SPECT scan * Blood and DNA (optional) sample collection * Questionnaires in regards to neuropathy, carpal tunnel, frailty, and Heart failure symptoms and how they may affect ones quality of life * 6-Minute Walk Test * ECG (electrocardiogram) * Echocardiogram Electronic health records will be reviewed for up to 5 years in order to determine hospitalization and survival of the study participants. Clinical outcomes of interest include a combined endpoint of days alive outside of the hospital from heart failure hospitalizations at one and five years, presence of autonomic neuropathy, presence of carpal tunnel syndrome, presence of polyneuropathy. Additionally, Individual clinical endpoints are also endpoints of interest. The results from this study will be used to determine how frequently heart failure patients have transthyretin amyloidosis in their heart and better understand their symptoms. We hope that better understanding transthyretin amyloidosis in heart failure patients will help us identify affected patients so that they can receive treatment.