Structural Microvascular Dysfunction: Remodeling and Capillary Rarefaction in Ischemia with Nonobstructive Coronary Arteries.

Structural coronary microvascular dysfunction (CMD) is an important endotype of ischemia with nonobstructive coronary arteries (INOCA) and is characterized by adverse arteriolar remodeling and capillary rarefaction. These alterations impair coronary vasodilator capacity and increase microcirculatory resistance, all of which contribute to impaired myocardial perfusion. In this article, we aim to review the anatomic and pathophysiological basis of structural CMD, its clinical presentation and prognostic relevance, and the role of invasive physiologic indices in its identification. We also highlight new considerations about dynamic aspects of structural CMD laying the groundwork for emerging therapeutic strategies and future research directions.