Microcalcification and Thoracic Aortopathy: A Window Into Disease Severity

Area of Science:

• Cardiovascular Biology
• Medical Imaging
• Pathology

Background:

• Thoracic aortopathy patients face high risks of aortic dissection, mortality, and morbidity.
• Granular medial calcinosis (medial microcalcification) is linked to thoracic aortopathy, but its role in disease severity is unclear.

Purpose of the Study:

• To investigate the relationship between medial microcalcification and the severity of thoracic aortopathy.
• To evaluate 18F-sodium fluoride (18F-NaF) autoradiography as a method to quantify microcalcification in vivo.

Main Methods:

• Analysis of 101 thoracic aortic specimens from patients with thoracic aortopathy and control subjects.
• Histopathology, immunohistochemistry, and nanoindentation were correlated with microcalcification levels.
• 18F-NaF autoradiography was used to assess microcalcification in aortic tissues.

Main Results:

• Microcalcification was higher in mild and moderate thoracic aortopathy compared to controls.
• Increased alkaline phosphatase and osteopontin staining were observed in early aortopathy.
• Severe degeneration correlated with reduced microcalcification, elastin loss, and decreased tissue elasticity.
• 18F-NaF autoradiography correlated well with histological microcalcification and identified focal weaknesses.

Conclusions:

• Medial microcalcification serves as a marker for aortopathy.
• Severe aortopathy involves loss of elastin and microcalcification.
• 18F-NaF positron emission tomography is a promising noninvasive imaging tool for detecting aortic wall disruption.