Vascular calcification by conventional X-ray and mortality in a cohort of predominantly African descent hemodialysis patients

Abstract

Background/objective: There is a lack of studies describing the prevalence of vascular calcification (VC) and its association with mortality in maintenance hemodialysis (MHD) patients of African descent. We investigated if a VC score based on the number of calcified vascular beds was associated with mortality in MHD patients.

Methods: We analyzed data from 211 MHD patients enrolled from January 2010 to January 2011 in the prospective cohort study, "The Prospective Study of the Prognosis of Chronic Hemodialysis Patients (PROHEMO)," developed in Salvador, BA, Brazil. VC was evaluated using radiographs of the hands, abdomen, hip, and chest; the score was calculated by the number of calcified sites as 0 (absence of calcification), 1 (one calcified site), 2 (two sites), 3 (⩾3 sites). We used Cox's regression to estimate the hazard ratio (HR) and 95% confidence interval (CI) of associations between VC and mortality with adjustments for age and comorbidities.

Results: VC was detected in 114 (54.0%) patients; 37 (17.5%) with a VC score = 1; 21 (10%) with VC score = 2 and 56 (26.5%) with VC score = 3. Compared with VC score = 0, the adjusted hazard of death was 2.67 (95% CI: 1.12, 6.33) for patients with VC score = 1; HR = 2.89 (95% CI: 0.95, 7.63) for VC score = 2; and HR = 3.27 (95% CI: 1.47, 7.28) for VC score = 3.

Conclusion: The present study in an African descent MHD population provides support for the VC score based on conventional radiography as a prediction tool for the clinical practice. As shown, the VC score was monotonically and independently associated with mortality.

Keywords: Abdominal aortic calcification; hemodialysis; mortality; vascular calcification.