Comparative study of calcified changes in aortic valvular diseases.

Area of Science:

• Cardiovascular Pathology
• Biomedical Engineering
• Histology and Ultrastructure

Background:

• Aortic valve calcification, leading to stenosis or regurgitation, is a significant clinical issue.
• Understanding the distinct mechanisms of calcification in different aortic valve diseases is crucial for targeted therapies.
• Rheumatic aortic valvular disease (RAVD), degenerative aortic valve disease (DAVD), and congenitally bicuspid aortic valves (CBAV) represent key etiological categories.

Purpose of the Study:

• To elucidate the comparative mechanisms of heart valve calcification across RAVD, DAVD, and CBAV.
• To correlate histological and ultrastructural findings with specific disease types.
• To identify unique pathological features contributing to calcification in each condition.

Main Methods:

• Comparative histological and ultrastructural examinations of calcified aortic valves from 31 patients.
• Patient groups included RAVD (n=11), DAVD (n=10), and CBAV (n=10).
• Electron microscopy was performed on 5 cases from each group.

Main Results:

• Histology showed calcification in degenerated areas (RAVD) and near the valve ring (DAVD).
• CBAV exhibited similar changes to DAVD, with additional severe calcification at the raphe.
• Ultrastructural analysis revealed common electron-dense material deposition patterns, but distinct fibrillar structures (RAVD) and lipid vacuoles (DAVD, CBAV) were noted.

Conclusions:

• Nutritional deprivation and connective tissue necrosis may drive calcification in RAVD.
• Hemodynamic stress and collagen degeneration in DAVD and CBAV contribute to calcification, with lipid deposition playing a role.
• While ultrastructural calcification patterns are similar, the underlying causes and mechanisms vary significantly among different aortic valve diseases.