The relationship between intradialytic hypotension and vascular calcification in hemodialysis patients

BACKGROUND Vascular calcification is associated with structural and functional abnormality of the heart and blood vessels. We investigated the relationship between intradialytic hypotension (IDH) and vascular calcification in hemodialysis (HD) patients, and their impacts on cardiovascular events (CVEs). METHOD We enrolled 191 maintenance HD patients who underwent plain abdomen radiography for abdominal aortic calcification score (AACS). A nadir systolic blood pressure (BP) < 90 mm Hg or the requirement of bolus fluid administration was required to quantify the hypotension diagnosis. IDH was defined as > 2 hypotension episodes during 10 HD treatments. RESULTS Among the 191 patients, IDH occurred in 32. AACS was higher in the IDH group compared with the no-IDH group (8.4 ± 6.0 vs. 4.9 ± 5.2, respectively; P = 0.001). High AACS was an independent risk factor after adjustment for age, diabetes mellitus, ultrafiltration, diastolic BP, and calcium level (odds ratio (OR) = 1.09, 95% CI = 1.01-1.18; P = 0.03). Patients with both IDH and AACS ≧ 4 had the highest cumulative CVE rate (27.9%, P = 0.008) compared with 11.2%, 12.5%, and 6% for those with AACS ≧ 4 only, with IDH only, and neither, respectively. In multivariate analysis, the presence of both IDH and AACS ≧ 4 was a significant predictor of CVE (hazard ratio (HR) = 2.84, 95% CI = 1.04-7.74, P = 0.04). CONCLUSION IDH is associated with abdominal aortic calcification and is an independent risk factor for IDH. Both IDH and high AACS were significant predictors of CVE.