Abstract
Background:
Fetuin A is a circulating calcium-regulatory glycoprotein that inhibits ectopic and vascular calcification. Aortic stenosis (AS) is a disease process involving an active calcification of the aortic valve (AV). Its prevalence increases markedly with aging. We examined the association between plasma level of Fetuin A and disease progression in AS
Methods and Results:
114 patients operated for AS, were divided into 2 groups according to their age: the young and middle-age group included the first (25–65 y-o) and second (66–74 y-o) tertiles and the elderly group included the last tertile (range 75–88 y-o). Plasma Fetuin-A level was determined by Elisa method and calcium content of the AV by a chelator quantitative method respectively. The annualized progression rate of the disease was calculated for the subset of patients in whom at least 2 transthoracic echocardiography separated by at least 6 months were available pre-operatively. In the elderly group, the preoperative progression rate of the maximum transvalvular gradient was 2-fold faster in patients with decreased plasma Fetuin-A level <0.36 ng/ml (median value) when compared to those with higher level of Fetuin-A (10±4 vs. 5±3 mmHg, p=0.01). Moreover, there was a significant correlation between calcium content of the AV explanted at the time of surgery and Fetuin-A plasma level (R=0.37, p<0.01). After adjusting for age, gender, bicuspid AV, creatinine, Fetuin-A remained significantly associated with AV calcification (R
2
=0.26, p=0.02). There was no correlation between Fetuin-A level and AV calcium content or AS progression in the younger patients group (R=0.06, p=0.62 and R=0.05, p=0.76, respectively)
Conclusion:
In the elderly patients, decreased level of Fetuin-A may contribute to enhanced valvular calcification and accelerated stenosis progression