Calcium Prescription in Hemodialysis: Study Highlights Impacts on Patient Survival Rates

The researchers found no significant differences in all-cause or cardiovascular mortality between patients undergoing hemodialysis who are prescribed dialysate calcium at 1.50 mmol/L compared to those receiving 1.25 mmol/L.

"Unlike the unadjusted analysis, which indicated a higher risk associated with a dialysate calcium level of 1.50 mmol/L, the adjusted analysis revealed no significant differences in all-cause or cardiovascular mortality between dialysate calcium concentrations of 1.50 and 1.25 mmol/L," the researchers wrote. "Following adjustment, patients receiving dialysate calcium at 1.50 mmol/L exhibited a lower risk of sudden cardiac death. Additionally, a higher serum-to-dialysate calcium gradient was linked to an increased risk of adverse outcomes."

The optimal prescription of dialysate calcium concentration for hemodialysis remains a topic of debate. As a result, Jeroen P. Kooman, Maastricht University Medical Centre+, Maastricht, the Netherlands, and colleagues explored the relationship between dialysate calcium levels and all-cause mortality, cardiovascular mortality, and sudden cardiac death.

For this purpose, the researchers conducted a historical cohort study that included adult patients who began hemodialysis between January 1, 2010, and June 30, 2017, and survived for at least six months (the grace period). They assessed the relationship between dialysate calcium concentrations of 1.25 or 1.50 mmol/L and various outcomes over the two years following the grace period. Additionally, the study explored the association between the serum-to-dialysate calcium gradient and these outcomes.

The following were the key findings of the study:

• The study included 12,897 patients receiving dialysate calcium at 1.25 mmol/L and 26,989 patients at 1.50 mmol/L, with a median age of 65 years, of whom 61% were male.
• The unadjusted risk of all-cause mortality was higher for those on dialysate calcium 1.50 mmol/L, showing a hazard ratio (HR) of 1.07.
• In the fully adjusted model, no significant differences were found, with an HR of 1.05.
• Similar trends were observed for cardiovascular mortality risk, which had an HR of 1.03.
• The adjusted risk of sudden cardiac death was lower for patients on dialysate calcium 1.50 mmol/L, with an HR of 0.81.
• The analysis also revealed significant positive associations with all outcomes concerning larger serum-to-dialysate calcium gradients, primarily influenced by serum calcium levels.

Based on the findings, the researchers suggest that the prescription of dialysate calcium should take into account individual patient characteristics, aligning with the guidelines set forth by European Renal Best Practice.

Reference:

Ter Meulen, K. J., Carioni, P., Bellocchio, F., M, F., Bouman, H. J., Stuard, S., Neri, L., & Kooman, J. P. (2024). The effects of dialysate calcium prescription on mortality outcomes in incident patients on hemodialysis. Clinical Kidney Journal, 17(10). https://doi.org/10.1093/ckj/sfae288