scholarly journals Reduced Microvascular Blood Volume as a Driver of Coronary Microvascular Disease in Patients With Non-obstructive Coronary Artery Disease: Rationale and Design of the MICORDIS Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Caitlin E. M. Vink ◽  
Tim P. van de Hoef ◽  
M. J. W. Götte ◽  
E. C. Eringa ◽  
Yolande Appelman
Keyword(s):  
Blood Volume ◽  
Contrast Echocardiography ◽  
Coronary Vasospasm ◽  
Circulating Endothelial Cells ◽  
Control Group ◽  
Coronary Microvascular Dysfunction ◽  
No Production ◽  
Flow Reserve ◽  
Myocardial Blood Volume ◽  
Function Testing

Background: Ischemia with non-obstructive coronary arteries (INOCA) is part of the ischemic heart disease spectrum, and is particularly observed in women. INOCA has various mechanisms, such as coronary vasospasm and coronary microvascular dysfunction (CMD). A decreased coronary flow reserve (CFR) and-or increased myocardial resistance (MR) are commonly used to diagnose CMD. However, CFR and MR do not describe all pathophysiological mechanisms underlying CMD. Increased myocardial oxygen consumption (MVO2) normally increases myocardial blood volume (MBV), independently from myocardial blood flow (MBF). In addition insulin enhances MBV in healthy skeletal muscle, and this effect is impaired in INOCA-related conditions such as diabetes and obesity. Therefore, we propose that MBV is reduced in INOCA patients.Aim: To assess whether myocardial blood volume (MBV) is decreased in INOCA patients, at baseline, during hyperinsulinemia and during stress.Design: The MICORDIS-study is a single-center observational cross-sectional cohort study (identifier NTR7515). The primary outcome is MBV, compared between INOCA patients and matched healthy controls. The patient group will undergo coronary function testing using a Doppler guidewire, intracoronary adenosine and acetylcholine to measure CFR and coronary vasospasm. Both the patient- and the control group will undergo myocardial contrast echocardiography (MCE) to determine MBV at baseline, during hyperinsulinemia and during stress. Subsequently, cardiac magnetic resonance (CMR) will be evaluated as a new and noninvasive diagnostic tool for CMD in INOCA patients. Microvascular endothelial function is a determinant of MBV and will be evaluated by non-invasive microvascular function testing using EndoPAT and by measuring NO production in circulating endothelial cells (ECFCs).

Changes in myocardial blood volume with graded coronary stenosis

1997 ◽  
Vol 272 (1) ◽  
pp. H567-H575 ◽  
Author(s):  
J. R. Lindner ◽  
D. M. Skyba ◽  
N. C. Goodman ◽  
A. R. Jayaweera ◽  
S. Kaul
Keyword(s):  
Coronary Artery ◽  
Left Atrium ◽  
Blood Volume ◽  
Coronary Stenosis ◽  
Contrast Echocardiography ◽  
Random Order ◽  
Myocardial Blood Volume ◽  
Coronary Artery Stenoses ◽  
The Mean ◽  
Stenotic Vessel

Vasodilation of microvessels distal to a stenosis results in an increase in myocardial blood volume (MBV). The purpose of this study was to examine the changes in MBV induced by graded coronary artery stenoses by using myocardial contrast echocardiography (MCE). Accordingly, 21 dogs underwent progressive stenosis of a coronary artery in a random order, the severity of which was judged by the pressure distal to it. Total myocardial blood flow (MBF) to the bed distal to the artery (both anterograde and collateral) was measured by injection of radiolabeled microspheres into the left atrium. In seven dogs, anterograde and total MBF were measured at each stenosis stage by injection of different microspheres into the left atrium and directly into the coronary artery, respectively. MBV was calculated by dividing MBF by the mean transit rate of microbubbles injected directly into the coronary artery during MCE. The perfusion bed size of the artery was also measured by MCE. Our major findings are as follows: 1) there is a nonlinear increase in MBV with increasing degrees of coronary stenosis until the coronary stenosis becomes critical; 2) at moderate levels of coronary stenosis, MBV remains constant despite ongoing autoregulation because of reduction in the size of the perfusion bed supplied by the stenotic vessel; and 3) after exhaustion of autoregulation, a decrease in MBV is noted with increasing levels of stenosis. We conclude that assessment of MBV provides insights into myocardial perfusion distal to a coronary stenosis above and beyond that provided by the measurement of MBF alone.

Abstract 2085: Increased Regional Coronary Vascular Resistance During Hyperemia in Hypertrophic Cardiomyopathy Is Associated with Reduced Myocardial Blood Volume

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hiroshi Komatsu ◽  
Satoshi Yamada ◽  
Masanao Naya ◽  
Hisao Onozuka ◽  
Taisei Mikami ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Blood Volume ◽  
Vascular Resistance ◽  
Contrast Echocardiography ◽  
Interventricular Septum ◽  
Power Doppler ◽  
Doppler Imaging ◽  
Coronary Vascular Resistance ◽  
Coronary Resistance ◽  
Myocardial Blood Volume

Introduction: In patients with hypertrophic cardiomyopathy ( HCM ), myocardial blood flow ( MBF ) is decreased during hyperemia because of high coronary vascular resistance. Recently myocardial blood volume ( MBV ) can be estimated in vivo using myocardial contrast echocardiography ( MCE ) with the compensation for acoustic field inhomogeneity. The relationship between MBV and coronary resistance, however, has not been investigated. We thus assessed the hypothesis that increased regional coronary vascular resistance during hyperemia in HCM is associated with reduced MBV. Methods: In 13 patients with HCM ( H , 53±16 years) with asymmetric septal hypertrophy and 9 normal volunteers ( N , 54±11 years), MCE was performed under infusion of Levovist at rest and during hyperemia induced by ATP. Apical 4-chamber views of intermittent harmonic power Doppler imaging were acquired at end-diastole of every sixth beat. MBV was calculated as 10 X/10 ×100%, where X was myocardial contrast intensity minus contrast intensity of the adjacent intracavity blood pool in dB. 15 O-water PET was performed to measure regional MBF. These parameters were measured in the interventricular septum ( IVS ) and LV posterolateral ( PL ) wall. Regional coronary vascular resistance was calculated as (mean blood pressure)/MBF. Results: Wall thickness was significantly greater in H than in N (IVS: 19±4 vs 10±1 mm, p<0.0001; PL: 10±1 vs 9±1 mm, p<0.05). MBV of IVS was lower in H than in N (rest: 2.1±0.7 vs 3.5±1.1%, p<0.01; hyperemia: 2.1±1.3 vs 4.3±1.7%, p<0.01), whereas MBV of PL wall did not differ between groups. Coronary resistance at rest did not differ between groups, but the resistance during hyperemia was significantly greater in H than in N (IVS: 59±16 vs 31±14 mmHg·min·g·ml −1 , p<0.001; PL: 40±10 vs 30±11 mmHg·min·g·ml −1 , p<0.05). Coronary resistance at rest did not correlate with MBV, whereas that during hyperemia inversely correlated with MBV during hyperemia (r=−0.77, p<0.0001) as well as MBV at rest (r=−0.65, p<0.0001). Conclusions: Increased coronary vascular resistance during hyperemia in HCM was significantly associated with reduced MBV. MCE is useful for assessing the dynamic function of coronary circulation in the clinical setting.

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