Coronary microvascular dysfunction: Past, present, and future of an evolving disease

Coronary atherosclerosis is the main cause of myocardial ischemia. Nevertheless 10-30% of patients with angina has angiographically normal coronary arteries. In the last 30 years, several studies showed that in these patients the symptoms can be caused by dysfunction of the coronary microcirculation. Coronary microvascular dysfunction (CMVD) occurring in patients affected by specific cardiac or systemic diseases may be due to mechanisms of the underlying disease. On the other hand, in several patients affected by angina with angiographically normal coronary arteries, there is no specific disease, and CMVD only is responsible for the clinical picture. This condition can be defined as leading microvascular angina in order to distinguish it from other forms of microvascular angina where CMVD is related to the presence of a specific disease. As regards pathogenesis, there are still many uncertainties, though evidence suggesting a role for certain risk factors rather than others is gradually emerging, along with the demonstration of new alterations of endothelial function. Also as regards therapy, and prognosis above all, the debate is still open.