Coronary Function Testing: Seeking Answers for Refractory Chest Pain

Case reportA 73-year-old man with a complex coronary history was referred for evaluation of chronic angina.He had a history of acute myocardial infarction for which he underwent percutaneous coronary intervention (PCI) to his left circumflex and first diagonal arteries.This was followed by repeat PCI of the circumflex 1 month later and eventual coronary artery bypass grafting 1 year after his index acute coronary syndrome event with grafts to the first diagonal and obtuse marginal arteries, all approximately 10 years prior to this presentation.Recent hospitalization for unstable angina requiring frequent sublingual nitrate administration prompted repeat coronary angiography, which revealed a new highgrade stenosis of his patent ductus arteriosus, prompting intravascular ultrasound-guided PCI.He reported an initial improvement of symptoms, but angina returned less than a week later despite optimization of medical therapy.Given severely limiting angina despite complete revascularization, he was referred for coronary function testing (CFT) for evaluation of angina.