Oral Nitrite in Patients With Pulmonary Hypertension and Heart Failure With Preserved Ejection Fraction

Inclusion Criteria: Age 18 years and older PH-HFpEF confirmed diagnosis by RHC: * Mean Pulmonary Arterial Pressure (mPAP) ≥ 25 mmHg AND * Pulmonary capillary wedge pressure (PWCP) ≥ 15 mmHg AND * Transpulmonary Gradient (TPG) ≥ 12 mmHg Exclusion Criteria: * Age less than 18 years; * SBP \> 170 or \< 110 mmHg * DBP \>95 or \< 60 mmHg * Hemoglobin A1C \> 10 * Positive urine pregnancy test or breastfeeding; * Ejection Fraction (EF) \< 40%; * Dementia * End-stage malignancy * Major cardiovascular event or procedure within 6 weeks prior to enrollment * Severe valvular disease * Known chronic psychiatric or medical conditions that may increase the risk associated with study participation in the judgment of the investigator, would make the subject inappropriate for entry into this study; * Smoker * Hemoglobin \<9 g/dL * Serum creatinine \> 3.0 mg/dL * Receipt of an investigational product or device, or participation in a drug research study within a period of 15 days; RHC \< 2 weeks from study screening RHC unless clinically indicated