Four-Year Report on Renal Outcomes Following Elective Withdrawal of Long-Term RAAS Blockade in a Cohort of Patients with Otherwise Inexplicable New-Onset and Progressive Acute Kidney Injury

Background: RAAS blockade is renoprotective for both diabetic and non-diabetic CKD. There have been discordant reports on renal and cardiovascular outcomes following RAAS blockade discontinuation in advanced CKD. To the contrary, a few prospective cohort studies have demonstrated reversal of otherwise inexplicable AKI in patients after discontinuation of RAAS blockade. This is a 4-year report of such a cohort. Methods: Prospective Cohort Analysis, enrolled between February 2018 – May 2021. Kidney function was monitored after elective withdrawal of long-term RAAS blockade in CKD patients presenting with new-onset otherwise inexplicable progressive AKI as defined by a > 25% increase in baseline serum creatinine. Results: By February 2022, 12 patients had died, and 8 patients were on hemodialysis for ESRD. The remaining 51 patients, with a baseline serum creatinine of 1.30 ± 0.42 (0.66–2.70) mg/dL, have been followed up for 706 (40-1478) days. Peak serum creatinine at study entry was 2.17 ± 1.06 (1.1–8.3) mg/dL, n = 51, P < 0.0001, t = 6.4872, df = 135. Serum creatinine, 48 months later, was 1.58 ± 0.54 (0.84–3.3) mg/dL, n = 50, p < 0.0001, t = 5.1805, df = 119. Death in 7 of 8 (87.5%) patients were from non-renal causes; most deaths occurred despite improved kidney function. Conclusion: Elective withdrawal of long-term RAAS blockade in CKD patients with new-onset progressive yet otherwise inexplicable AKI results in significant sustainable renal salvage. Such self-selected patients generally exhibit improved renal outcomes without increased mortality. This is consistent with late-onset renal failure from angiotensin blockade (LORFFAB), first described in 2005 from the Mayo Clinic Health System in Northwestern Wisconsin.