Phosphate binders, cardiovascular calcifications and mortality: do we need another survival study with sevelamer?

In chronic renal failure patients, hyperphosphatemia has been associated with vascular calcifications and increased cardiovascular morbidity and mortality. In vitro observations have shown that calcium and phosphate independently and synergistically induce calcifications in human vascular smooth muscle cells, suggesting an important role for both in the calcification process. Because non-calcium phosphate binders reduce serum phosphate without increasing the calcium load, as is the case with calcium-based phosphate binders, it has been speculated that treatment with sevelamer leads to less vascular calcification and better survival in chronic kidney disease. Although the use of sevelamer may slow the progression of vascular calcifications compared with calcium-based phosphate binders, the relationship of this surrogate marker with patients' cardiovascular mortality and survival is far from certain. To resolve this uncertainty and to determine the most cost-effective way to treat hyperphosphatemia in patients with end-stage renal disease, another randomized study analyzing mortality comparing sevelamer with calcium phosphate binders should be undertaken.