A Study of Oral Nitrate in Adults With Pulmonary Hypertension With Heart Failure and Preserved Ejection Fraction

This is an open-label, single-center study to examine distinguishing features of the structure and function of the oral and gut microbiome in healthy adult normal volunteers compared to volunteers with PH-HFpEF in the breakdown of oral nitrate.

We will enroll 60 Group II PH (PH-HFpEF) or Group I PAH patients and 60 matched healthy controls over three years. The Subjects will receive a single dose of one of the two study drugs, determined by whether they will participate in one study visit or two: 15N nitrate (1,000 mg) or 14N Sodium Nitrate: standard sodium nitrate, and all will receive one dose of CLA 3g. Twenty of the PH or PAH subjects and 20 of the control subjects willing to return for a follow up visit 24 hours after drug administration will receive 15N nitrate. All others will receive standard sodium nitrate. CLA will be obtained from GNC (General Nutrition Corporation) and given once. Throughout the experiment, we will measure blood pressure, heart rate, and respiratory rate as well as co-oximetry. Plasma samples are collected at approximate times 0, 2, and 6 hrs post-drug administration. Urine will be collected at approximate times 0 and 6 hrs. We will examine plasma and urine nitrate and nitrite. The 40 subjects who return for a second visit 24 hours post-drug administration will provide an additional plasma and urine sample.