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Updated: Jun 7, 2026
A Methodological Approach to Non-invasive Assessments of Vascular Function and Morphology
Published on: February 7, 2015
Noninvasive visualization of coronary artery endothelial function in healthy subjects and in patients with coronary
Allison G Hays1, Glenn A Hirsch, Sebastian Kelle
1Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, Maryland, USA.
Insights
Noninvasive 3.0-T MRI can now detect abnormal coronary endothelial function. This method visualizes how local coronary artery disease (CAD) severity impacts endothelial function, offering new risk stratification insights for patients with CAD.
Area of Science:
- Cardiovascular imaging
- Noninvasive diagnostics
- Coronary artery disease research
Background:
- Abnormal endothelial function is key in atherosclerosis and predicts cardiovascular events.
- Previous direct measures of coronary endothelial function required invasive procedures.
Purpose of the Study:
- To determine if clinical 3.0-T MRI can noninvasively measure coronary endothelial function.
- To investigate the relationship between the extent of coronary artery disease (CAD) and local abnormal coronary endothelial function.
Main Methods:
- Magnetic resonance imaging (MRI) was used in 20 healthy adults and 17 patients with CAD.
- Coronary artery area and blood flow were measured before and during isometric handgrip exercise.
- In 10 CAD patients, paired endothelial function was assessed in severely and mildly diseased arteries.
Main Results:
- Healthy adults showed coronary artery dilation and increased blood flow with stress.
- CAD patients exhibited decreased coronary artery area and blood flow during stress (p ≤ 0.02).
- In paired studies, severely diseased arteries showed significant decreases in area and flow (p ≤ 0.02), while mildly diseased arteries failed to increase flow.
Conclusions:
- Noninvasive 3.0-T MRI can visualize and quantify endothelial-dependent coronary artery dilation and blood flow.
- Absence of normal response observed in CAD patients.
- Local coronary endothelial function varies with CAD severity within the same patient, suggesting new risk stratification potential.
Objectives:
The goal was to test 2 hypotheses: first, that coronary endothelial function can be measured noninvasively and abnormal function detected using clinical 3.0-T magnetic resonance imaging (MRI); and second, that the extent of local coronary artery disease (CAD), in a given patient, is related to the degree of local abnormal coronary endothelial function.
Background:
Abnormal endothelial function mediates the initiation and progression of atherosclerosis and predicts cardiovascular events. However, direct measures of coronary endothelial function have required invasive assessment.
Methods:
The MRI was performed in 20 healthy adults and 17 patients with CAD. Cross-sectional coronary area and blood flow were quantified before and during isometric handgrip exercise, an endothelial-dependent stressor. In 10 severe, single-vessel CAD patients, paired endothelial function was measured in the artery with severe stenosis and the contralateral artery with minimal disease.
Results:
In healthy adults, coronary arteries dilated and flow increased with stress. In CAD patients, coronary artery area and blood flow decreased with stress (both p ≤ 0.02). In the paired study, coronary artery area and blood flow failed to increase during exercise in the mildly diseased vessel, but both area (p = 0.01) and blood flow (p = 0.02) decreased significantly in the severely diseased, contralateral artery.
Conclusions:
Endothelial-dependent coronary artery dilation and increased blood flow in healthy subjects, and their absence in CAD patients, can now be directly visualized and quantified noninvasively. Local coronary endothelial function differs between severely and mildly diseased arteries in a given CAD patient. This novel, safe method may offer new insights regarding the importance of local coronary endothelial function and improved risk stratification in patients at risk for and with known CAD.
