Clinical features of hemodialysis patients with intimal versus medial vascular calcifications.

BACKGROUND: Vascular calcifications (VCs) contribute to the massive mortality in hemodialysis (HD) patients. We aimed to identify prevalence and risk factors for arterial medial calcifications (AMCs) versus intimal calcifications (AICs) in a single-center HD population.

METHODS: This cross-sectional study included 134 patients, mean age 56.9 +/- 9.7 years, on HD for 8.2 +/- 5.0 years. VCs were scored based on plain radiographs and ultrasonography of the common carotid arteries.

RESULTS: Patients were categorized into groups I (13% without VC), II (10% with an AMC pattern), III (24% with an AIC pattern) and IV (53% with a mixed pattern). AIC and mixed patterns were associated with older age (p=0.006 and p=0.004, respectively), and mixed pattern with longer dialysis vintage (p=0.001). Pulse pressure was significantly higher in patients from group III than group IV, and intima-media thickness (IMT) was higher in both groups with AIC. By multivariate analysis, risk factors for any VC were high serum Ca, phosphate, CaxP product, low total protein, high body mass index (BMI), systolic and diastolic blood pressure, IMT and history of smoking. Elevated calcium and/or phosphate predicted an AMC pattern, and high calcium, BMI and IMT an AIC pattern. Finally, high IMT, systolic blood pressure, BMI and older age were predictors of a mixed pattern.

CONCLUSION: We observed a very high prevalence of VC, mostly with a mixed AIC+AMC pattern. Apart from well-known risk factors, the data stress the importance of smoking, an under-recognized cause of AMC, and systolic blood pressure for AIC+AMC.