Page 161 - Coronary hemodynamics in acute myocardial infarction - Matthijs Bax
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Time course of coronary flow capacity in STEMI
upregulated catecholamines.3 The current study utilized the CFC concept to document the time course of microvascular function in the setting of STEMI in both the culprit and the non-culprit arteries.
It also revealed that despite restored epicardial patency of the culprit, a substantial number of patients remained having a severely reduced CFC, which improved over time. As previously documented for CFR, we also observed an impaired CFC in the non-culprit artery remote from the ischaemic region. However, compared with the culprit vessel, CFC in the non-culprit vessel was less impaired in the acute setting and improved more rapidly over time.
Previous studies on microvascular function in STEMI
Myocardial tissue perfusion remains compromised in 30–40% of STEMI patients
despite rapid and successful mechanical revascularization.17,18 Whereas culprit
vessel flow abnormalities have been ascribed to numerous pathophysiological mechanisms, including reperfusion injury, distal embolization of plaque
and thrombus material, endothelial dysfunction, leucocyte plugging and
external compression of the microvasculature, the pan-myocardial nature
of microvascular dysfunction is less well-understood, but has partly been
ascribed to metabolic consequences of STEMI.3,19 Microvascular dysfunction
in the infarct related artery as well as remote regions from the infarct related myocardium observed after primary PCI are associated with a significantly
increased long-term clinical outcome and mortality.11,20–23 In addition, CFR
obtained directly after primary PCI is an independent predictor of long term
global as well as regional recovery of left ventricular function.24,25 However, 9 microvascular dysfunction in the setting of STEMI is often disclosed as a
decrease in hyperaemic flow and increase in resting flow. The ratio of these, that is, the coronary flow reserve, does not provide insights into the relative contribution of both components.
Clinical implication
Risk stratification in the setting of AMI has long remained to be elucidated, and recent findings of large clinical trials have led to a revived interest in the approach to STEMI patients with multivessel disease. Revascularization of multivessel
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