Challenges in diagnosing coronary microvascular dysfunction and coronary vasospasm.

Chronic coronary syndromes (CCS) include 2 overlapping subgroups of patients - those with angina with nonobstructive coronary arteries (ANOCA), or ischaemia with non-obstructive coronary arteries (INOCA). A diagnosis of ANOCA-INOCA, is common and should be considered where angina is present and/or ischaemia is found on functional imaging in the absence of obstructive coronary artery disease (CAD) on coronary computed tomography angiography (CCTA) or invasive coronary angiography (ICA) (Ford and Berry, 2019). This review aims to provide an overview of contemporary challenges in the diagnosis of coronary microvascular dysfunction (CMD) and vasospastic disease, with a focus on recent guideline changes and current controversies. CMD and vasospastic angina (VSA) are increasingly acknowledged as an important and frequently overlooked, under investigated, and undertreated entities that contribute to ANOCA-INOCA (Samuels et al., 2023; Kunadian et al., 2020; Ford and Berry, 2019; Burgess and Mamas, 2024).