Heart failure with preserved ejection fraction (HFPEF) or diastolic heart failure is a common and highly morbid condition.
1 Clinical trials of renin-angiotensin system antagonists have not demonstrated improvement in outcomes or clinical status in HFPEF, and effective therapies are needed.
2 Phosphodiesterase-5 (PDE-5) metabolizes the nitric oxide and natriuretic peptide systems' second messenger cyclic guanosine monophosphate and thus may limit beneficial nitric oxide and natriuretic peptide actions in the heart, vasculature, and kidneys.