TNFRSF1A and heart failure: The study presented herein expands on previous work by exploring associations between diastolic dysfunction or heart failure severity, and plasma levels of TNFα, TNFR1 and TNFR2, as well as a non-TNFα family cytokine, interleukin-6 (IL-6), in community-based cohorts of healthy controls, and ambulatory HFPEF and HFREF patients.