Study Design and Participants
chest tightness, chronic kidney disease
ChaMP-CMD is a phenotype-blinded randomized crossover trial performed at a tertiary referral cardiac center in London, UK. This study was approved by the National Health Service Research Ethics Committee (reference 20/LO/1294), funded by the UK Medical Research Council, and overseen by a trial steering committee. Written informed consent was obtained from all patients before their enrollment. The study protocol was registered before the first patient was enrolled (International Standard Randomised Controlled Trial Number: ISRCTN94728379).We recruited patients with predictable exertional chest tightness, preserved left ventricular ejection fraction (>50%), and unobstructed coronary arteries (fractional flow reserve >0.80). Exclusion criteria were intolerance to adenosine, advanced chronic kidney disease (estimated glomerular filtration rate <30 mL·min