Target hemoglobin trials in chronic kidney disease: design and interpretation issues

Predialysis anemia management and outcomes following dialysis initiation: A retrospective cohort analysis

Whether and how anemia treatment with erythropoiesis stimulating agents (ESAs) before hemodialysis initiation may be associated with lower mortality after dialysis initiation is unknown. We compared all-cause and cardiovascular mortality in two groups of patients who experienced distinct anemia treatment patterns with ESAs before and after hemodialysis initiation. This retrospective cohort analysis included patients initiating hemodialysis April 1, 2012-June 30, 2013, identified from United States Renal Data System end-stage renal disease (ESRD) and pre-ESRD files. Patients treated with ESAs before and after hemodialysis initiation who maintained Hb ≥ 9.0 g/dL throughout (comparator group, n = 3662) were compared with patients with Hb < 9.0 g/dL before hemodialysis initiation (with or without ESAs) whose levels increased with ESAs after hemodialysis initiation (referent group, n = 4461). Cox proportional hazards models were used to calculate the hazard ratio of all-cause and cardiovascular mortality after hemodialysis initiation. Of 20,454 patients, 4855 (23.7%) had Hb < 9.0 g/dL upon hemodialysis initiation; of these 4855, 26.6% received ESAs before initiation. Comparator group Hb levels increased from 8.2 ± 0.8 mg/dL upon initiation to 10.9 ± 1.2 with ESAs afterward. Comparator patients were more likely than referent patients to be younger (76.3 ± 6.7 versus 77.2 ± 6.9 years), male (51.5% versus 49.8%), and black (24.6% versus 18.6%). Risk of all-cause mortality was lower for the comparator group versus the referent group at 3 (HR 0.83, 95% CI 0.68–1.00, P = 0.052), 6 (0.86, 0.74–1.00, P = 0.047), and 12 (0.88, 0.78–0.99, P = 0.036) months. The pattern was similar for cardiovascular mortality. Hb ≥ 9.0 with ESAs before and after hemodialysis initiation was generally associated with lower post-initiation all-cause and cardiovascular mortality compared with predialysis Hb < 9.0 g/dL in patients whose Hb levels subsequently improved with ESAs after hemodialysis initiation.

Anemia in chronic kidney disease: new advances

Anemia resulting from iron and erythropoietin deficiencies is a common complication of advanced chronic kidney disease (CKD). This article covers major advances in our understanding of anemia in patients with CKD, including newly discovered regulatory molecules, such as hepcidin, to innovative intravenous iron therapies. The use of erythropoiesis-stimulating agents (ESA) in the treatment of anemia has undergone seismic shift in the past 3 years as a result of adverse outcomes associated with targeting higher hemoglobin levels with these agents. Potential mechanisms for adverse outcomes, such as higher mortality, are discussed. Despite the disappointing experience with ESAs, there is a tremendous interest in other novel agents to treat anemia in CKD. Lastly, while awaiting updated guidelines, the authors outline their recommendations on how to best manage patients who are anemic and have CKD.