Coronary and Peripheral Haemodynamic Studies of Angina with Normal Coronary Arteries

This study is for people who have chest pain (angina) but whose coronary angiogram shows no significant blockages in the heart arteries. Researchers want to do a thorough set of heart and blood vessel tests to find the underlying cause — such as spasms or tiny vessel problems — and follow patients to see what affects their ongoing chest pain. You may be eligible if: - You are aged 18 to 80 - You have been diagnosed with angina - Your coronary angiogram showed normal or minimally narrowed arteries (less than 50% blockage) - You continue to experience chest pain You may NOT be eligible if: - You had an acute heart attack within the past month - You have had coronary bypass surgery (CABG) in the past - You have a pacemaker or defibrillator - You have severe kidney or liver disease, severe asthma, or poor heart pumping function - Your chest pain has a clear alternative explanation such as an obstructive blockage or coronary artery dissection - You have pulmonary hypertension, hypertrophic cardiomyopathy, or significant valve disease Talk to your doctor about whether this trial might be right for you.