Diffuse and focal epicardial coronary disease and coronary microvascular abnormalities may exist side-by-side. Coronary microvascular dysfunction (CMD) may explain why angina persists in a substantial portion of patients after successful revascularisation.
This review by U. Sechtem et al. (Robert Bosch Krankenhaus, Stuttgart, Germany) focuses on the challenges of identifying the presence of CMD in the context of diffuse non-obstructive CAD and obstructive CAD. The authors review the aetiologies of CMD with structural and functional causes and summarise the current knowledge on coronary vasomotor abnormalities relevant to CMD in patients with stable IHD with a special reference to endothelial modulation of vascular tone and coronary microvascular spasm (CMS). They refer to CMD as a cardiac manifestation of systemic small artery disease which supports the concept of “primary coronary microcirculatory dysfunction”. Take-home message: accumulating evidence has demonstrated that CMD plays an important role in the pathophysiology of myocardial ischaemia in patients with stable ischaemic heart disease (IHD). In clinical practice, diagnosing the additional presence of CMD is difficult and often requires invasive diagnostic testing. However, establishing a diagnosis of CMD has important consequences for therapy and prognosis. CMD may explain why angina persists in a substantial portion of patients after successful revascularization.