Benefits of Aldosterone Receptor Antagonism in Chronic Kidney Disease (BARACK D) trial-a multi-centre, prospective, randomised, open, blinded end-point, 36-month study of 2,616 patients within primary care with stage 3b chronic kidney disease to compare the efficacy of spironolactone 25 mg once daily in addition to routine care on mortality and cardiovascular outcomes versus routine care alone: study protocol for a randomized controlled trial

Background: Chronic kidney disease (CKD) is common and increasing in prevalence. Cardiovascular disease (CVD) is a major cause of morbidity and death in CKD, though of a different phenotype to the general CVD population. Few therapies have proved effective in modifying the increased CVD risk or rate of renal decline in CKD. There are accumulating data that aldosterone receptor antagonists (ARA) may offer cardio-protection and delay renal impairment in patients with the CV phenotype in CKD. The use of ARA in CKD has therefore been increasingly advocated. However, no large study of ARA with renal or CVD outcomes is underway. Methods: The study is a prospective randomised open blinded endpoint (PROBE) trial set in primary care where patients will mainly be identified by their GPs or from existing CKD lists. They will be invited if they have been formally diagnosed with CKD stage 3b or there is evidence of stage 3b CKD from blood results (eGFR 30-44 mL/min/1.73 m(2)) and fulfil the other inclusion/exclusion criteria. Patients will be randomised to either spironolactone 25 mg once daily in addition to routine care or routine care alone and followed-up for 36 months. Discussion: BARACK D is a PROBE trial to determine the effect of ARA on mortality and cardiovascular outcomes (onset or progression of CVD) in patients with stage 3b CKD.