Matching Perfusion and Metabolic Activity in HFpEF
This study will test whether pharmacologic agents that increase perfusion \[Potassium Nitrate (KNO3)\], with and without additional supplements that may improve mitochondrial function \[Propionyl-L-Carnitine (PLC) and Nicotinamide Riboside (NR)\], improve submaximal exercise endurance and skeletal muscle oxidative phosphorylation capacity (SkM OxPhos) in participants with Heart Failure with Preserved Ejection Fraction (HFpEF).
• NYHA Class II-III symptoms
• Left ventricular ejection fraction \>= 50%
• Stable medical condition for at least 2 weeks, as per investigator judgment
• Prior or current evidence for elevated filling pressures as follows:
• a. Mitral early (E)/mitral septal tissue annular (e') velocity ratio \> 8, in the context of a septal e' velocity \<=7, in addition to one of the following: i. Large left atrium (LA volume index \> 34 mL/m2) ii. Chronic loop diuretic use for control of symptoms iii. Elevated natriuretic peptides within the past year (e.g. NTproBNP \> 125 pg/mL in sinus rhythm or \> 375 pg/mL if in atrial fibrillation) b. Mitral E/e' ratio \> 14 at rest or during exercise c. Elevated invasively-determined filling pressures previously (resting left ventricular end-diastolic pressure \>= 16 mm Hg or pulmonary capillary wedge pressure \>= 15 mmHg; or PCWP/LVEDP \>= 25 mmHg with exercise) d. Prior episode of acute heart failure requiring IV diuretics