Chest pain in the absence of obstructive coronary artery disease: A critical review of current concepts focusing on sex specificity, microcirculatory function, and clinical implications.

Patients presenting with chest pain suggestive of coronary artery disease (CAD) who at coronary arteriography appear to be free of obstructive disease have presented a diagnostic and therapeutic challenge since the 1970's. Studies in female patient populations have suggested that this is predominantly a women's syndrome usually caused by microvascular endothelial dependent and independent dysfunction. A critical review of the literature focusing on studies including both women and men revealed that apart from a higher incidence of this syndrome in women there are no clinical relevant differences between both sexes. In women a lower coronary flow reserve has been reported but this appears to be mainly due to a higher basal flow. Important questions with regard to the clinical implications of microvascular dysfunction have yet to be resolved in studies involving women as well as men in which a distinction is made between patients with normal coronary arteries and those with nonobstructive disease.