Methods:
Patients with eGFR<30ml/min/1.73m2 and progressive CKD were randomized, to stop or continue RASi. Primary outcome was eGFR over 3-years using repeated-measures, mixed-effects linear regression, random-slope models. Cox models were used to calculate hazard ratios for time-to-event outcomes, including ESKD and KRT.
Results:
At baseline, eGFR, arterial pressure and proteinuria were similar for 133 patients taking loop diuretics and 278 who were not. Those receiving loop diuretics at randomization, least-squares mean (±SE) eGFR at 3-years was 12.3 (±1.1) for those stopping compared to 10.1 (±1.2) for those continuing RASi, trend favouring stopping RASi (+2.2; 95% CI, –0.9 to +5.4), but eGFR slope over 3-years was similar (-7.2 vs -7.7 ml/min/1.73m2). Those not receiving loop diuretics, eGFR at 3-years was 8.8 (±0.8) and 11.6 (±0.8) (discontinue and continue RASi groups), a difference favouring continuing RASi (–2.8; 95% CI, –4.9 to -0.8), and a steeper eGFR slope for those discontinuing RASi (-9.9 vs -7.6 ml/min/1.73m2). The interaction between loop diuretic use and the effect of RASi on eGFR at 3-years and the three-way interaction between diuretic subgroup, effect of RASi and time were both statistically significant (p=0.01 and p=0.04 respectively). Of patients taking loop diuretics, 73 (55%) developed ESKD/KRT, and 23 (17%) died. Of patients not taking loop diuretics, 170 (61%) developed ESKD/KRT and 19 (7%) died.
Conclusions:
Withdrawal of RASi was associated with a steeper decline in eGFR over 3-years in those not receiving loop diuretics but this was not observed in those who were taking loop diuretics. Patients receiving loop diuretics had a high mortality. These data support the need for randomised trials investigating the efficacy and safety of loop diuretics in patients with advanced CKD.
