Collagen and Elastin Changes in Degenerative Diseases of Heart Valves

Degenerative diseases of heart valves (aortic stenosis, mitral valve prolapse and degenerative regurgitation) are widespread among the pathologies of the cardiovascular system, especially in elderly patients. The main morphological substrate of these diseases is the structural and functional changes in collagen and elastin fibers contained in the extracellular matrix of heart valves. Under normal conditions, collagen provides mechanical strength of the valve, while elastin maintains its elasticity and adaptability to hemodynamic loads. During the degenerative process, disorganization, hyperproduction and redistribution of collagen fibers, as well as fragmentation and degradation of elastic fibers are observed. These changes are closely related to the transition of fibroblasts to the myofibroblast phenotype, impaired activity of matrix metalloproteinases and activation of TGF-β signaling pathways. As a result, fibrosis, matrix remodeling and gradual calcification develop. Osteoblast-like differentiation of interstitial cells enhances the mineralization process. This article analyzes the normal histological structure of heart valves, the mechanisms of changes in collagen and elastin at the molecular level, and their hemodynamic consequences. The stages and clinical significance of the degenerative process are also highlighted from a morphological point of view. The results of the study provide a scientific basis for a deeper understanding of the pathogenesis of degenerative valvular diseases and the development of new therapeutic approaches.