Current perspectives in coronary microvascular dysfunction

Abstract

The coronary arterial system consists of large epicardial coronary arteries, pre-arterioles, and arterioles, which together closely regulate CBF. Structural, functional, and extravascular abnormalities of the microcirculation lead to CMD. CMD can present with symptoms suggestive of CAD, often in the absence of significant obstructive epicardial CAD. Conventional invasive angiography does not allow direct visualization of the microcirculation. Invasive indices, such as CBF and CFR, and non-invasive imaging modalities, such as CMR and PET, can be used to quantify absolute MBF and enable a direct and accurate assessment of coronary microvascular function. CMD appears to be more prevalent in women, typically presenting with symptoms of ischemia with unobstructed coronary arteries, and has a relatively unfavorable prognosis. CMD is classified clinically depending on the presence or absence of epicardial CAD, myocardial disease, or iatrogenic causes. Although invasive intracoronary techniques can be used to detect CMD, these cannot provide insight into the mechanisms involved in its pathogenesis. Imaging modalities such as CMR and cardiac PET are becoming indispensable tools in the evaluation of suspected CMD.

Diabetic Cardiomyopathy

“…106 Structural abnormalities in the coronary microcirculation include luminal obstruction, inflammation infiltration, vascular remodeling, and perivascular fibrosis. 107 Functional abnormalities in the coronary microcirculation include endothelial and smooth muscle cell dysfunction and impairment of vascular relaxation and constriction and ischemic reperfusion. 107 The normal function of coronary arteries, and downstream microcirculatory vessels, is impaired in diabetic cardiomyopathy (Fig.…”

<p>SGLT2 Inhibitors: A Novel Player in the Treatment and Prevention of Diabetic Cardiomyopathy</p>

“…79 Structural abnormalities of coronary artery microcirculation include inflammatory infiltration, lumen obstruction, perivascular fibrosis, and vascular remodeling. 80 Regarding functional aspects, coronary microcirculation abnormalities include dysfunction of endothelial cells and smooth-muscle cells and ischemic reperfusion and dysfunction of vascular relaxation and constriction. 80 Cardiac microvascular endothelial cells (CMECs), the main cells in cardiac microcirculation, suffer hyperglycemic injury much more easily than cardiomyocytes.…”

“…80 Regarding functional aspects, coronary microcirculation abnormalities include dysfunction of endothelial cells and smooth-muscle cells and ischemic reperfusion and dysfunction of vascular relaxation and constriction. 80 Cardiac microvascular endothelial cells (CMECs), the main cells in cardiac microcirculation, suffer hyperglycemic injury much more easily than cardiomyocytes. 81 The progression of DM contributes to depletion of CMEC viability and metabolic defects in vascular smooth-muscle cells.…”

Coronary Microvascular Dysfunction and the Role of Noninvasive Cardiovascular Imaging

“…CFR is determined by taking measurements of coronary blood flow both at rest (basal flow) and with maximal hyperemia achieved by pharmacological/vasodilator stress. CFR is then expressed as the ratio of blood flow during hyperemia to the blood flow at rest [ 6 , 9 , 12 , 27 , 28 ]. There is no unified range for a normal CFR.…”