Evaluating the effects of sevelamer carbonate on cardiovascular structure and function in chronic renal impairment in Birmingham: the CRIB-PHOS randomised controlled trial

To determine the effects of phosphate binding with sevelamer carbonate on left ventricular mass and function together with arterial stiffness in patients with stage 3 chronic kidney disease.A single-centre, prospective, randomised, double-blind, placebo-controlled trial of 120 subjects with stage 3 chronic kidney disease recruited from University Hospitals Birmingham NHS Foundation Trust. Baseline investigations include transthoracic echocardiography and cardiac magnetic resonance imaging to assess ventricular mass, volumes and function, applanation tonometry to determine pulse wave velocity and pulse wave analysis as surrogate measures of arterial stiffness and dual energy x-ray absorptiometry scanning to determine bone density. During an open-label run in phase, subjects will receive 1600 mg sevelamer carbonate with meals for four weeks. They will then be randomised to either continue sevelamer carbonate or receive an identical placebo (60 subjects per arm) for the remaining 36 weeks. Four-weekly monitoring of serum electrolytes and bone biochemistry will be performed. All baseline investigations will be repeated at the end of the treatment period. The primary endpoint of the study is a reduction in left ventricular mass after 40 weeks of treatment. Secondary endpoints are: i) change in aortic compliance; ii) change in arterial stiffness; iii) change in arterial elastance; iv) change in left ventricular systolic and diastolic elastance; v) change in left ventricular function; and vi) change in bone density.This trial is registered at ClinicalTrials.gov: NCT00806481 and Current Controlled Trials: ISRCTN35254279.The risk of cardiovascular disease is elevated in patients with chronic kidney disease (CKD) with an inverse graded relationship to glomerular filtration rate (GFR) independent of other risk factors [1]. The magnitude of this excess risk varies according to age, but for patients with moderately impaired renal function at stage 3b CKD (GFR 30-44 ml/min/1.73 m