The Impact of Renin-Angiotensin System Blockade on Renal Outcomes and Mortality in Pre-Dialysis Patients with Advanced Chronic Kidney Disease

Renin-angiotensin-system (RAS) blockade is thought to slow renal progression in patients with chronic kidney disease (CKD). However, it remains uncertain if the habitual use of RAS inhibitors affects renal progression and outcomes in pre-dialysis patients with advanced CKD. In this multicenter retrospective cohort study, we identified 2,076 pre-dialysis patients with advanced CKD (stage 4 or 5) from a total of 33,722 CKD patients. RAS blockade users were paired with non-users for analyses using inverse probability of treatment-weighted (IPTW) and propensity score (PS) matching. The outcomes were renal death, all-cause mortality, hospitalization for hyperkalemia, and interactive factors as composite outcomes. RAS blockade users showed an increased risk of renal death in PS-matched analysis (hazard ratio [HR], 1.381; 95% CI, 1.071-1.781; P = 0.013), which was in agreement with the results of IPTW analysis (HR, 1.298; 95% CI, 1.123-1.500; P < 0.001). The risk of composite outcomes was higher in RAS blockade users in IPTW (HR, 1.154; 95% CI, 1.016-1.310; P = 0.027), but was marginal significance in PS matched analysis (HR, 1.243; 95% CI, 0.996-1.550; P = 0.054). The habitual use of RAS blockades in pre-dialysis patients with advanced CKD may have a detrimental effect on renal outcome without improving all-cause mortality. Further studies are warranted to determine whether withholding RAS blockade may lead to better outcomes in these patients.