Testing new supplements to improve exercise ability in heart failure patients

This trial is testing whether Potassium Nitrate can help people with a specific type of heart failure called HFpEF (heart failure with preserved ejection fraction) exercise longer and feel less tired. Researchers will also test whether adding two other supplements—propionyl-L-carnitine and nicotinamide riboside—works better than the medication alone. The study will help doctors figure out which patients benefit most from each treatment option.

People with HFpEF often struggle with exercise and shortness of breath, even though their heart's pumping strength looks normal on tests. Current treatments don't adequately address the underlying muscle and energy problems that cause these symptoms, so this trial is exploring whether this medication and supplements can improve how the body uses oxygen during exercise.