Values of osteoprotegerin in aortic valve tissue in patients with significant aortic stenosis depend on the existence of concomitant coronary artery disease

Atherosclerosis, calcific aortic valve disease and mitral annular calcification: same or different?

There are similarities in the pathophysiologic mechanisms of atherosclerosis, calcific aortic valve disease (CAVD) and mitral annular calcification (MAC), however, medical treatment to slow or stop the progression of CAVD or MAC has been more elusive as compared to atherosclerosis. Atherosclerosis and CAVD share common demographic, clinical, protein, and genetic factors even more so than with MAC, which supports the possibility of shared medical therapies, though abrogating calcific extracellular vesicle shedding could be a common target for all three conditions. Herein, we summarize the overlapping and distinct pathways for further investigation, as well as key areas where additional research is needed.

NOTCH1 Mutations in Aortic Stenosis: Association with Osteoprotegerin/RANK/RANKL

Background. The NOTCH pathway is known to be important in the pathogenesis of calcific aortic valve disease, possibly through regulators of osteoprotegerin (OPG), receptor activator of nuclear factor κB (RANK), and its ligand (RANKL) system. The purpose of the present study was to search for possible associations between NOTCH1 gene mutations and circulating levels of OPG and soluble RANKL (sRANKL) in patients with aortic stenosis (AS). Methods. The study was performed on 61 patients with AS including 31 with bicuspid and 30 with tricuspid aortic valves. We applied a strategy of targeted mutation screening for 10 out of 34 exons of the NOTCH1 gene by direct sequencing. Serum OPG and sRANKL levels were assessed. Results. In total, 6 genetic variants of the NOTCH1 gene including two new mutations were identified in the study group. In an age- and arterial hypertension-adjusted multivariable regression analysis, the serum OPG levels and the OPG/sRANKL ratio were correlated with NOTCH1 missense variants. All studied missense variants in NOTCH1 gene were found in Ca(2+)-binding EGF motif of the NOTCH extracellular domain bound to Delta-like 4. Conclusion. Our results suggest that the OPG/RANKL/RANK system might be directly influenced by genetic variants of NOTCH1 in aortic valve calcification.

Serum Osteoprotegerin Is Associated With Calcified Carotid Plaque: A Strobe-Compliant Observational Study

Osteoprotegerin (OPG) is a kind of tumor necrosis factor, which is related to bone metabolism and vascular calcification. The increase of Osteoprotegerin concentration in serum is related to cardiovascular diseases in humans. The purpose of this study was to figure out the relevance between osteoprotegerin in serum and carotid calcification. Serum OPG concentrations were compared in 145 patients who underwent carotid sonography (average age: 68 ± 9 years old, male: female = 81:64). A calcified plaque (CP) (37 people [27%]), a noncalcified plaque (NCP) (54 people [37%]), and a nonplaque (NP) (54 people [37%]) were classified for this study. No significant differences among 3 groups were demonstrated in the distribution of age, diabetes, high blood pressure, and hyperlipidemia. Serum osteoprotegerin concentrations were significantly increased in CP group rather than NCP group or NP group; (median [interquartile range], 4016 [1410] vs 3210 [1802] pg/mL, P < 0.05 and 4016 [1410] vs 3204 [1754] pg/mL, P < 0.05). Serum osteoprotegerin concentrations did not indicate a significant difference between NCP Group or NP Group. This study had proved that patient group accompanied with carotid calcification in carotid artery disease had an increased serum OPG concentration, so it could consider that OPG plays an important function on calcification related to arteriosclerosis.