Evolutive aortic stenosis in hemodialysis patients: analysis of risk factors

Abstract

Cardiovascular diseases represent the major cause of death in hemodialysis patients. However, little information is available about the repercussion of uremia on cardiac valves. We retrospectively investigated the incidence rate of aortic stenosis (AS), from 1991 to 1996, in 110 hemodialysis patients followed by Doppler-echocardiography. Progressive AS was diagnosed in 16 patients who had a decrease in their indexed aortic valve area from 1.24 +/- 0.09 to 0.66 +/- 0.21 cm2/m2 of BSA in 16.8 +/- 1.9 months. The mean incidence of AS per year was of 3.3%, ranging from 1.5 to 8.0%. Eight patients died in less than 3 years after the diagnosis of AS with a mean survival time of 23.0 +/- 9.5 months. Survival curves using Kaplan-Meier estimates showed a statistically significant decrease in the survival rate of patients with AS compared with patients without valvulopathy (p < 0.001). They were older than patients with normal valve, 68.6 +/- 11.1 versus 56.7 +/- 16.0 years, respectively. Men were 4 times more affected than women and showed a significantly more rapid progression to AS than women. The calcium-phosphorus product was higher in AS patients, 5.43 +/- 0.98 than in patients without AS, 3.95 +/- 0.50 mM. It was mainly due to hyperphosphatemia without hypercalcemia and the hyperphosphatemia was associated with biological signs of hypoparathyroidism or adynamic bone disease in 62% of the cases. Plasma vitamin D3 was also higher in patients with AS, 20.5 +/- 13.5 ng/ml than in those with normal valves, 9.6 +/- 6.3 ng/ml. Logistic regression showed that age, vitamin D3 and hyperphosphatemia correctly predicted 56% of the AS cases. In conclusion, AS is frequent and of poor outcome in hemodialysis patients. Age, relatively high plasma vitamin D3 levels, and hyperphosphatemia, mostly due to hypoparathyroidism, must be considered as risk factors.