Cardiovascular calcification: Orbicular origins

Ageing is strongly associated with increases in calcium accumulation in the aortic valve, coronary arteries and aorta. Clinically, valve replacement surgery for calcific aortic valve stenosis is the second most common thoracic procedure performed in the US, and calcification of the coronary arteries and aorta are strong predictors of morbidity and mortality in ageing humans. By starting with topographical scanning of normal and calcified cardiovascular tissues using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), they find that normal valve tissue is uniform and entirely organic, whereas calcified tissue contains dense structures in three distinct forms: spherical particles, dense fibers and compact material. Interestingly, although EDS analysis of these structures reveal that their elemental structure is highly comparable to bone, SEM-EDS analysis of human bone samples failed to identify the presence of spheroid structures.