"Treatment of Anemia with Darbepoetin Alfa in Systolic Heart Failure"
NEJM Mar 10
http://www.nejm.org/doi/full/10.1056/NEJMoa1214865 
"CONCLUSIONS 

Treatment with darbepoetin alfa did not improve clinical outcomes in patients with systolic heart failure and mild-to-moderate anemia. Our findings do not support the use of darbepoetin alfa in these patients."