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.