Calcification in human vessels and valves: from pathological point of view

Vascular and valvular calcification are commonly encountered in clinical medicine and a greater understanding of their significance and pathophysiology remain a subject of immense importance. In the coronary arteries, vascular calcification burden correlates with the severity of luminal stenosis and atherosclerotic plaque burden. While in progressive lesions, the presence of coronary calcification is not binary but rather depends on the type of calcification. Racial and gender differences, and comorbidities like diabetes mellitus and chronic kidney disease, all affect the presence and severity of calcification. The peripheral arteries of the lower extremities are affected by both medial calcification and intimal calcification, and the former barely contributes to luminal stenosis. The character of atherosclerosis differs between above-knee and below-knee lesions. Valvular calcification generally occurs on the aortic valve leaflets, and pathologic findings range from minimal fibrocalcific changes in early disease to end-stage lesions characterized by fibrotic thickening and nodular calcification. Valvular calcification is similar to atherosclerotic changes, in terms of lipid deposition, inflammation, osteogenic differentiation of valvular interstitial cells, and oxidative stress. However, the mechanisms of vascular and valvular calcification are still not well understood. A deeper understanding of vascular and valvular calcification is needed in order to develop effective anti-calcification therapies and to improve outcomes in these patients.