Investigating the Effects of Dietary Nitrate on Vascular Function, Platelet Reactivity and Restenosis in Stable Angina

Inclusion Criteria: 1. Patients with stable angina diagnosed by a cardiologist on optimal medical therapy undergoing angioplasty to treat residual symptoms. 2. Aged 18-85 3. Patients able and willing to give their written informed consent. 4. Patients undergoing successful PCI procedure. Exclusion Criteria: 1. Unstable ischaemic heart disease, with an episode of chest pain in less than 24 hours. 2. Patients who have had previous coronary artery bypass surgery (CABG), if they are undergoing angioplasty within a non-native vessel. 3. Patients undergoing angioplasty with a bio-absorbable stent. 4. Current diagnosis of or treatment for malignancy, other than non-melanoma skin cancer. 5. Current life-threatening condition other than vascular disease that may prevent a subject completing the study. 6. Use of an investigational device or investigational drug within 30 days or 5 half-lives (whichever is the longer) preceding the first dose of study medication. 7. Patients considered unsuitable to participate by the research team (e.g., due to medical reasons, laboratory abnormalities, or subject's unwillingness to comply with all study related procedures). 8. Severe acute infection, or significant trauma (burns, fractures). 9. Pregnancy. This will be tested by urine human chorionic gonadotropin (hCG) measurement 10. History of alcohol or drug abuse within the past 6 months. 11. A history of heart failure New York Heart Association (NYHA) class 3-4 or severe left ventricular dysfunction (left ventricular ejection fraction of \<30%) regardless of symptom status. 12. Systemic autoimmune disease such as rheumatoid arthritis, connective tissue disease, or other conditions known to be associated with chronic inflammation such as inflammatory bowel disease. 13. Patients who have donated \> 500mls blood within 56 days prior to study medication administration. 14. Anaemia with Hb \<10g/dl, or any other known blood disorder or significant illness that may affect platelet function, and coagulation. 15. A history of chronic viral hepatitis (including presence of hepatitis B surface antigen or hepatitis C antibody or other chronic hepatic disorder) or HIV. 16. Abnormal liver function due to acute or chronic liver conditions 3 x upper limit of normal at screening. 17. Renal impairment with creatinine clearance (eGFR) of 35ml/min at screening. 18. If patients are on mouthwash, they must be willing to stop using this at least 1 week before the start of the study and throughout the duration that they are involved in the study.