Late-onset renal failure from angiotensin blockade (LORFFAB) in 100 CKD patients.

Introduction: Notwithstanding proven renoprotection from RAAS blockade (AB) with ACE inhibitors and ARBs, and despite increasing utilization of AB in the US, we have continued to experience a CKD/ESRD epidemic. Given concerns for iatrogenic CKD/ESRD, we designed a prospective study to analyze the course of eGFR following withdrawal of AB in such patients.

Patients: Between September 2002 and February 2005, all consecutive CKD patients on AB presenting with >25% increase in baseline serum creatinine were enrolled. eGFR following withdrawal of AB was monitored. The main outcome measures were serum creatinine, MDRD eGFR, and UA/Cr.

Results: 100 Caucasians, M:F=52:48, mean age 71.5 years were enrolled. Mean follow up was 26 months. Sixteen patients progressed to ESRD, of whom seven died. In 74, eGFR improved from 23.9+/-9 (7-47) to 39.2+/-15.4 (17-89) ml/min/1.73 m(2) BSA, 26.5 (3-46) months after stopping AB (P=0.001). The majority of the cohort, 95 patients, had known risk factors: 26 with RAS, 12 hypovolemia, 11 sepsis, 10 NSAIDs/cox II inhibitor use/abuse, 7 CIN, 2 congestive heart failure, 2 obstructive uropathy, and 27 with other medical and surgical causes, including malignancies, postoperative states, and infections. In the 26 with RAS, 5 with higher baseline creatinine -2.1+/-0.6 versus 1.5+/-0.4 mg/dL, P=0.013, progressed to ESRD; 4/5 ESRD patients died after 6.3 months. The remaining five patients (one male and four females), mean age 68 (44-83) years, demonstrated sustained improved eGFR with discontinuation (four) or reduction (one) of RAAS blockade, despite normal renal arteries and the absence of known traditional risk factors. UA/Cr generally increased following withdrawal of AB.

Conclusions: Worsening azotemia in older susceptible CKD patients on AB, often but not always associated with known precipitating risk factors, remains under-recognized. Sustained improved eGFR often follows the discontinuation of AB. The practising physician should be well aware of these syndromes. Our observations call for further study.