Altered myocardial microvascular 3D architecture in experimental hypercholesterolemia

Area of Science:

• Cardiovascular Research
• Microvascular Physiology
• Medical Imaging

Background:

• Experimental hypercholesterolemia (HC) is known to impair intramyocardial microvascular function.
• Previous studies have not clarified if HC is associated with changes in microvascular architecture.

Purpose of the Study:

• To investigate the hypothesis that HC is associated with alterations in myocardial microvascular architecture.
• To assess the feasibility of using 3D micro-CT for studying microvascular architecture in pathophysiological conditions.

Main Methods:

• Pigs were fed either a normal or a 2% HC diet for 12 weeks.
• Hearts were scanned using a novel 3D micro-CT scanner after coronary artery injection with radiopaque contrast material.
• Myocardial samples were analyzed to quantify microvessel density in subepicardial and subendocardial regions.

Main Results:

• The subendocardium of HC pigs showed significantly higher microvessel density compared to normal pigs.
• This increase in density was primarily due to a greater number of smaller microvessels (<200 microm).
• No significant difference in vascular density was observed in the subepicardium between groups.

Conclusions:

• HC induces differential changes in the spatial density of the subendocardial microvasculature.
• These architectural alterations may influence myocardial blood flow regulation and distribution.
• 3D micro-CT is a feasible tool for examining myocardial microvascular architecture in disease states.