['heart failure']
['sodium nitrite inhalation solution']

        Inclusion Criteria:

          -  Heart Failure with preserved Ejection Fraction (HFpEF) is defined by clinical symptoms
             of dyspnea and fatigue

          -  Normal left ventricular ejection fraction (>/=50%)

          -  And elevated Left Ventricular (LV) filling pressure at cardiac catheterization
             (defined as resting Pulmonary Capillary Wedge Pressure (PCWP)>15 mmHg and/or PCWP
             >/=25 mmHg during exercise).

        Exclusion Criteria:

          -  Systolic Blood Pressure <120 mmHg (during catheterization)

          -  Prior nitrate therapy (within previous 2 weeks)

          -  Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency

          -  Other "non-HFpEF" specific causes of heart failure such as significant valvular
             disease (>moderate left-sided regurgitation, >mild stenosis)

          -  Severe pulmonary disease

          -  Unstable coronary disease or coronary spasm

          -  Primary renal or hepatic disease (end stage renal failure/on dialysis or clinical
             diagnosis of hepatitis or hepatic cirrhosis)

          -  Constrictive pericarditis, or infiltrative, restrictive, or hypertrophic
             cardiomyopathies

          -  Pregnant
      