6-Year Prospective Study of Kidney Outcomes after Withdrawal of Concurrent RAAS Blockade in Patients Presenting with New, Progressive, Otherwise Inexplicable AKI

Background: We described the new syndrome of late onset renal failure from angiotensin blockade (LORFFAB) in 2005 – this was new progressive AKI defined by >25% increase in baseline creatinine in patients on concurrent stable RAAS blockade in the absence of known traditional precipitating risk factors. We present a 6-year prospective follow-up in our previously reported Vermont cohort following withdrawal of RAAS blockade in the face of new progressive otherwise inexplicable AKI. Methods: We conducted an ongoing interim prospective cohort analysis of patients enrolled between February 2018 and May 2021 in an outpatient Academic Nephrology Clinic in Vermont. Kidney function was monitored after elective withdrawal of long-term RAAS blockade in CKD patients presenting with new-onset otherwise inexplicable progressive AKI, defined by a >25% increase in baseline serum creatinine. Results: In 2022, there were 51 surviving patients from the original Vermont cohort of 71 patients - baseline serum creatinine (SC) was 1.30 ± 0.42 (0.66-2.70) mg/dL, peak enrollment SC was 2.17 ± 1.06 (1.1-8.3) mg/dL, and SC after four years was 1.58 ± 0.54 (0.84-3.3) mg/dL. By May 2024, there were 9 deaths, 5 ESRD, and 8 were restarted on RAAS blockade. 30 patients were available for this analysis - M:F=12:18, age 74.4 ± 9.1 (64-99), latest SC 1.59 ± 0.6 mg/dL (0.71 – 3.63); latest eGFR 45.2 ± 20.4 (16-101). Of the 9 patients that died, cause of death was mostly cardiac, and the majority died despite improved or stable renal function. SC trajectory of one of these patients following withdrawal of Olmesartan in January 2020 is demonstrative (Figure). Conclusion: There remains controversy as to the impacts of continuing versus discontinuing RAAS blockade in advanced CKD. Our report is peculiar since RAAS blockade was electively withdrawn in patients presenting with de novo progressive and otherwise inexplicable AKI. We believe that this specific group of patients unequivocally benefit from withdrawal of RAAS blockade (Figure).