Non-invasive Diagnosis of Coronary Microvascular Disease: Pilot Study

During invasive coronary angiography, in addition to coronary angiography performed as per routine clinical care, participants will have angiographic testing for coronary microvascular disease using routine clinical procedures. This will consist of fractional flow reserve (FFR), coronary flow reserve, index of microvascular resistance and vasospasm provocation testing with acetylcholine (Ach).

Participants will undergo a cardiac magnetic resonance scan compromising 1) T1 mapping, 2) oxygenation-sensitive MRI and 3) perfusion imaging. All will be obtained at rest and during exercise using a step ergometer.

Previously acquired CTCA images from the main research study will be transferred to Heartflow for computation of coronary blood volume.