RIDD-HFBH4 Treatment for Diastolic Dysfunction in Heart Failure

Heart failure is a serious condition affecting millions of people in the United States alone. About half of these individuals have a type of heart failure known as heart failure with preserved ejection fraction (HFpEF), or diastolic heart failure. This condition is characterized by symptoms such as shortness of breath, swelling, fatigue, and reduced exercise tolerance. The causes of diastolic heart failure are not fully understood, making it difficult to treat effectively. Currently, there are no FDA-approved treatments for this condition, and standard heart failure treatments do not work. This study focuses on a potential underlying cause of diastolic heart failure - a decrease in nitric oxide, a substance that helps regulate blood pressure and blood flow. Research suggests that a substance called BH4, which helps produce nitric oxide, might improve diastolic heart failure. However, the effects of BH4 on diastolic heart failure in humans have not been studied yet. In this treatment study, participants will receive BH4 to see if it can improve heart function. The main goal is to measure changes in oxygen consumption during maximum exercise, an indicator of heart and lung health. This will be assessed using a cardiopulmonary exercise test (CPET). The test results will be recorded in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min). An increase in oxygen consumption from the start to the end of the study suggests an improvement in heart and lung health.