PROJECT SUMMARY Heart failure (HF) is a critical public health issue that affects over 5 million US adults and imposes an enormous clinical, social, and economic burden. Over half of individuals with HF have HF with preserved ejection fraction (HFpEF). Furthermore, HFpEF is highly heterogeneous, and different pathologic mechanisms contribute to symptoms and poor outcomes in several different subgroups of the disease. Although several largescale randomized trials have been performed, no pharmacological therapies have been identified that improve symptoms or clinical outcomes in patients with HFpEF. Our group and others have identified that novel approaches to deeply phenotyping patients with HFpEF can identify subgroups of patients with HFpEF that are likely to benefit from targeted therapy. The overarching goal of the current proposal is to establish a large cohort of deeply phenotyped patients with HF with a focus on patients with HFpEF. We propose establishing a cohort of 1000 patients across all 4 Penn clinical centers: 700 patients with HFpEF, 200 patients with HFrEF (including 100 patients with mid-range LV EF, 40-50%) and 100 non-HF patients with hypertension (a suitable control population, given that most patients with HFpEF have a history of hypertension). We will incorporate comprehensive clinical data, socioeconomic data (particularly as they relate to social determinants of health), patient-centered data (such as quality of life and functional status), structural and mechanistic cardiac and extracardiac phenotypes (including in-lab characterization and innovative ambulatory approaches to data collection) and multi-omics approaches. The phenotypic data will be complemented by contemporary bioinformatic approaches to enhance our understanding of human HFpEF. Our phenotyping protocol will provide the opportunity for cross-sectional comparisons against other groups above, application of within-group clustering approaches, as well as establishing a comprehensively characterized large prospective cohort of patients with strictly adjudicated HFpEF for prospective follow-up of hard outcomes. In these patients, we will assess detailed cardiac and extracardiac phenotypes, electronic health record data, patient-reported outcomes, aerobic adaptations to exercise, and plasma and urinary proteomics and metabolomics and micro RNAs. We will also assess key ambulatory phenotypes including innovative approaches to home blood pressure monitoring, physical activity, sleep duration and quality, and important social determinants of health. Heart failure outcomes will be prospectively adjudicated, including heart-failure related hospitalization, death, myocardial infarction and stroke. Our analytic approach will include hypothesis-based research as well as unbiased discovery approaches that will leverage contemporary bioinformatics tools but will be subject to expert interpretation by members of the Steering Committee, investigator teams at the other Clin...