Mineralocorticoid receptor antagonists (MRAs) are underused in patients with kidney dysfunction, and their efficacy among patients with chronic kidney disease (CKD) is uncertain.The goal of this study was to analyze the efficacy and safety of steroidal MRAs across the spectrum of estimated glomerular filtration rates (eGFRs) in randomized controlled trials. The study included patients with heart failure (HF) or myocardial infarction and advanced CKD who participated in the RALES (Randomized Aldactone Evaluation Study), EMPHASIS-HF (Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure), TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist) in the Americas, and EPHESUS (Eplerenone Post-AMI Heart Failure Efficacy and Survival Study) trials.This study used individual patient data meta-analysis using Cox models stratified by trial with treatment-by-eGFR interaction terms. eGFR was recalculated by using the Chronic Kidney Disease Epidemiology Collaboration creatinine formula.A total of 12,700 patients were included, of whom 331 (2.6%) had an eGFR ≤30 mL/min/1.73 m2 (mean eGFR: 26.8 ± 3.2 mL/min/1.73 m2). Patients with advanced CKD had higher annualized event rates for all studied outcomes: placebo event rate for the composite of cardiovascular death or HF hospitalization was ∼3-fold higher in patients with eGFR ≤30 compared with those with eGFR >90 mL/min/1.73 m2: 41.6 vs 14.6 events per 100 person-years. MRAs (vs placebo) reduced the composite of cardiovascular death or HF hospitalization, but the effect was attenuated as eGFR decreased: the corresponding HRs by eGFR categories were: HR for >90 mL/min/1.73 m2: 0.62 (95% CI: 0.49-0.78); HR for 61-90 mL/min/1.73 m2: 0.69 (95% CI: 0.61-0.77); HR for 46-60 mL/min/1.73 m2: 0.84 (95% CI: 0.74-0.95); HR for 31-45 mL/min/1.73 m2: 0.79 (95% CI: 0.68-0.91); and HR for ≤30 mL/min/1.73 m2: 0.96 (95% CI: 0.70-1.32) (treatment-by-eGFR interaction P for trend = 0.033). Investigator-reported hyperkalemia and worsening renal function were more frequent (2- to 3-fold) among MRA users, and hyperkalemia was more frequent as eGFR decreased (treatment-by-eGFR interaction P for trend = 0.002).Steroidal MRAs reduced HF hospitalizations and mortality across a wide range of eGFR. However, declining benefit and worsening safety may limit their use in patients with lower eGFR, particularly those with levels ≤30 mL/min/1.73 m2.