Coronary artery calcification is a risk factor for intradialytic hypotension in patients undergoing hemodialysis

Introduction We investigated the association between intradialytic hypotension (IDH) and coronary artery calcification and their effects on mortality in hemodialysis (HD) patients. Methods Consecutive patients undergoing maintenance HD were enrolled. The study timeline included the baseline (day 1), exposure assessment (day 1-day 22), and outcome assessment (day 23-3 years) periods. IDH was defined as a nadir systolic blood pressure (SBP) of <100 mmHg or vasopressor use during at least 2 of 10 HD sessions in the exposure assessment period. The clinical data at baseline and the Agatston coronary artery calcium score (CACS) were assessed in the exposure assessment period. Findings The median age and dialysis vintage were 67 years [60-75 years] and 73 months [37-138 months], respectively. IDH occurred in 37 patients (21.4%), and the CACS was higher in the IDH group than in the non-IDH group (p = 0.08). IDH was associated with CACS, diabetes mellitus, mean predialysis SBP, and mean ultrafiltration volume (p < 0.05). The cutoff CACS for mortality was 1829 (sensitivity: 69%, specificity: 77%). In all, 45 all-cause deaths and 19 cardiovascular deaths occurred over 3 years. Patients with both IDH and a CACS of >= 1829 had a lower 3-year cumulative survival from cardiovascular death (66.7%) than those with a CACS of >= 1829 (80.3%), IDH (88.5%), or neither (95.5%) (p < 0.01). IDH, a CACS of >= 1829, and IDH + CACS of >= 1829 were predictors of 3-year all-cause and cardiovascular mortality (p < 0.05). The hazard ratio for cardiovascular mortality was highest in the group with IDH + CACS >= 1829. Discussion A high CACS may be a biomarker for IDH. Both IDH and CACS were risk factors for all-cause and cardiovascular mortality in patients undergoing HD, and there was a synergistic interaction between IDH and high CACS for cardiovascular mortality.