Inhibition of the renin-angiotensin-aldosterone system with an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin II receptor blocker (ARB) delays the progression of chronic kidney disease (CKD) in patients with and without diabetes mellitus, particularly those with mild to moderate renal insufficiency as reflected by a serum creatinine level of 1.5 to 3.0 mg/dL (to convert to micromoles per liter, multiply by 88.4).
1-4 Two randomized clinical trials in China
5,6 and a post hoc analysis of the Ramipril Efficacy in Nephropathy trial
7 further demonstrated that the use of ACEIs or ARBs is beneficial in patients with stage 4 CKD, defined by a glomerular filtration rate (GFR) of 15 to 29 mL/min/1.73 m
2 and a serum creatinine level of approximately 3.0 to 5.0 mg/dL, who do not have diabetes mellitus. However, data focusing on the use of ACEIs and/or ARBs in patients with serum creatinine levels of greater than 5.0 mg/dL or a GFR of less than 15 mL/min/1.73 m
2 are limited. Because most prospective, large-scale clinical trials of ACEI/ARB use excluded individuals with stage 5 CKD who were not undergoing dialysis (predialysis CKD), whether ACEI/ARB therapy should be used continuously in patients with advanced CKD remains unclear.