Calcification of Cardiac Valves in Metabolic Bone Disease: An Updated Review of Clinical Studies

Epidemiological and clinical data have suggested the existence of a relationship between cardiovascular diseases and metabolic bone disease. Several studies have demonstrated that heart valve calcification presents substantial similarities with that of bone. Literature data indicate that there are many active processes which promote osteogenesis and loss of mineralization inhibitors that lead to the deposition of extracellular matrix and proteins of bone tissue in cardiac valves. This review aimed to synthesize the available data in order to allow a better understanding of the relationship between osteoporosis or other metabolic bone diseases, such as primary hyperparathyroidism, and valvular calcification in humans. Electronic databases of Pubmed-Medline, Cochrane Library, and SCOPUS from inception to March 31, 2019 were searched. The full set of the articles potentially eligible were carefully assessed and reviewed. Finally, 23 studies were eligible and included in the systematic review. The majority of studies reported that osteoporosis and/or osteopenia were independent risk factors for valvular calcifications, even after adjusting for common cardiovascular risk factors. This suggests that this relationship is not only due to the presence of common cardiovascular risk factors but rather to underlying biological factors that connect them. Instead, regarding the association between primary hyperparathyroidism and valve calcification, conflicting data were found in the literature. To sum up, most of the literature data confirm that cardiac valve calcification processes are strongly influenced by alterations in bone metabolism. In particular, the patients with osteoporosis or primary hyperparathyroidism have an acceleration in the process of valvular calcification. Additional studies are needed to specifically address the mechanisms by which metabolic bone diseases could influence cardiac valve calcification.