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Key Points
- New data suggest that the presence of comorbidities such as heart failure or diabetes renders risk of death and cardiovascular morbidity associated with high hemoglobin targets clinically undetectable.
- Researchers observed no increased risk in the composite end point associated with higher target hemoglobin levels among participants with heart failure.
- Patients without heart failure, however, had an 86% increased risk.
Studies of anemia management in CKD patients have shown an increased risk of death and cardiovascular morbidity associated with high hemoglobin targets, but new data suggest that the presence of comorbidities such as heart failure or diabetes renders these risks clinically undetectable.
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Lynda A. Szczech, MD, of Duke University Medical Center in Durham, N.C., and colleagues conducted a subgroup analysis of patients in the Correction of Hemoglobin and Outcomes in Renal Insufficiency (CHOIR) study. CHOIR is a randomized trial comparing the effect of treatment with epoetin alfa to two hemoglobin targets (11.3 and 13.5 g/L) on the composite end point of death, heart failure hospitalization, stroke, and myocardial infarction in 1,432 patients with CKD and anemia.
Heart failure was significantly associated with hemoglobin target after adjusting for baseline characteristics. After adjusting for potential confounders, Dr. Szczech’s team observed no increased risk in the composite end point associated with higher target hemoglobin levels among participants with heart failure. Patients without heart failure, however, had an 86% increased risk.
Patients with diabetes did not have an increased risk associated with higher hemoglobin targets, although they had better survival in the low compared with higher hemoglobin target range. The interaction between diabetes and treatment arm, however, did not reach statistical significant in multivariable analyses.
Dr. Szczech and her group also examined the interaction between diabetes and heart failure. Patients who had no prior heart failure or diabetes had a twofold increased risk. Patients with diabetes but no history of heart failure had a 75% increased risk. Subjects with prior heart failure with or without diabetes were not at increased risk.
“These results suggest that the presence of these comorbidities attenuates the risk seen in the group randomized to the higher hemoglobin goal,” the authors concluded.
It is unclear whether the mechanism for this differential treatment effect might be due to the stronger effect of the comorbidity on outcome, they added.
