Invasive assessment of the coronary microcirculation in the catheter laboratory

Women with Stable Angina Pectoris and No Obstructive Coronary Artery Disease: Closer to a Diagnosis

“…28 These vasodilators assess endothelial-independent coronary microvascular function 27 in the absence of epicardial coronary artery stenosis. 29 Microvascular function is expressed as a flow reserve calculated as the ratio between flow during stress and rest. Although CMD should be seen as a continuum, 30 European guidelines suggest a flow reserve <2 as a strong indicator of CMD, 31 but studies have used both higher and lower cut-off values depending on the method of assessment.…”

“…37,41 Endothelial-independent function can also be assessed during vasodilator infusion with adenosine, dipyridamole or regadenoson with calculation of the coronary flow velocity reserve (CFVR). 29 Flow velocity changes in the coronary arteries are assumed to be representative of changes in flow volume due to dilation of the smaller resistance vessels, based on the assumption that coronary artery diameters remain constant during hyperaemia. However, dilation of the epicardial coronary arteries during hyperaemia may occur.…”

“…The ratio between number of angiographic frames for the contrast to reach a distal landmark at maximal hyperaemia and rest reflects coronary microvascular function and has shown good correlation with invasive CFVR. 29,43,44 CMD may also be assessed through thermodilution, although this method is less widely used. 45…”

A multi‐scale model of the coronary circulation applied to investigate transmural myocardial flow

“…The patterns of transmural myocardial flow will be further complicated by the activation of compensatory mechanisms under ischemic conditions . In the diagnosis of occlusive coronary artery disease, in addition to traditional angiographic evaluation of the severity of stenotic lesions in epicardial coronary arteries, attention has been increasingly paid to assessing the functional state of the coronary circulation with respect to, for example, coronary flow reserve, coronary flow capacity, microcirculatory resistance, myocardial flow reserve, and myocardial perfusion . Accordingly, many new techniques have been developed and examined in various clinical settings .…”

“…of occlusive coronary artery disease, in addition to traditional angiographic evaluation of the severity of stenotic lesions in epicardial coronary arteries, attention has been increasingly paid to assessing the functional state of the coronary circulation with respect to, for example, coronary flow reserve, coronary flow capacity, microcirculatory resistance, myocardial flow reserve, and myocardial perfusion. [6][7][8][9][10][11] Accordingly, many new techniques have been developed and examined in various clinical settings. 10,[12][13][14] Despite the well-documented diagnostic utility of these new techniques, in vivo measurement of intramyocardial hemodynamic variables remains challenging, which largely hampers a thorough understanding of transmural myocardial flow.…”