Phosphate control in hemodialysis (HD) patients using sevelamer rather than calcium carbonate is associated with a significant reduced risk of cardiovascular (CV) and all-cause mortality, data suggest.
In a 24-month open-label study of 466 HD patients randomized to receive one of these phosphate binders, two deaths resulting from cardiac arrhythmias occurred among the 232 patients who received sevelamer compared with 27 such deaths among the 234 patients who received calcium carbonate. In adjusted analyses, sevelamer treatment was significantly associated with a greater than 10-fold reduction in the risk of death from cardiac arrhythmias compared with calcium carbonate treatment, Biagio Di Iorio, MD, of A. Landolfi Hospital, Solofra, Avellino, Italy, and colleagues reported online ahead of print in the American Journal of Kidney Diseases. Compared with calcium carbonate, sevelamer was associated with a significant 10-fold decreased risk of any CV-related death and a significant 77% decreased risk of death from any cause. It was not associated with a decrease in non-CV mortality.
At baseline, 328 (70.4%) of the 466 subjects had coronary artery calcification (CAC). Patients in the sevelamer arm had a lower median CAC score than the calcium carbonate arm (19 vs. 30).
The sevelamer group had higher mean serum phosphorus levels than the calcium carbonate group (5.6 vs. 4.8 mg/dL).
The sevelamer group had better phosphorus control during the study compared with the calcium carbonate group. Phosphorus levels dropped from 5.6 mg/dL at baseline to 4.2 mg/dL at 24 months, a significant decline of 1.4 mg/dL; in the calcium carbonate group, phosphorus levels at baseline and at 24 months were 4.8 mg/dL. From baseline to 24 months, serum calcium levels declined significantly from 8.9 to 8.2 mg/dL in the sevelamer-treated patients but increased significantly from 8.8 to 9.6 mg/dL in the calcium carbonate recipients.
The authors noted that the better outcomes observed in the sevelamer arm may be due to better phosphate control rather than reduction in calcium load.
“The present study differs importantly from previous published studies in that it is larger, evaluates a hard patient-centered outcome, and has achieved significantly more complete follow-up of substantially longer duration,” the authors noted.