Risk of cardiovascular mortality predicted by the serum calcium level and calcification score at the initiation of dialysis

Background: The relationship between serum corrected calcium (CCa) level and vessel calcification at dialysis initiation and survival has seldom been evaluated. Therefore, we evaluated the efficacy of CCa levels and the calcification score at the initiation of dialysis for predicting all-cause and cardiovascular (CV) mortality in patients with end-stage renal disease (ESRD). Methods: The study group included 407 patients with ESRD, who started hemodialysis between January 2009 and December 2016 at the Red Cross Ishinomaki Hospital. The primary outcomes were the 1- and 3-year all-cause and CV mortality rate, with the association between CCa level and CVD-specific mortality evaluated using the Kaplan–Meier method and Cox proportional hazard regression analysis. Results: Patients with a high initial CCa level were at higher risk for CVD-related, but not all-cause, mortality than patients with a low initial CCa level [hazard ratio (HR) 2.81; 95% confidence interval 1.05–7.55]. The HR for CVD-related mortality was also higher for patients with an Agatston vessel calcification score > 2000 (HR 13.9; 95% CI 1.63–118.2). Overall, the 3-year CVD-free rate was 88.2% (range 76.4–94.3%). Higher CCa level was associated with a higher Agatston score and cardiac valve calcification. Conclusion: High serum CCa levels and an Agatston score > 2000 are independent risk factors of CVD mortality due to advanced vessel calcification.