Anemia as a risk factor for CKD and CVD

Chronic kidney disease (CKD) is now recognized as a risk factor of both end-stage renal disease (ESRD) and independently cardiovascular disease (CVD). Therefore, a specific renoprotective intervention is strongly recommended, including blood pressure control as well as anemia improvement with erythropoietin stimulating agents (ESAs). Treatment of renal anemia with ESAs has been proved to improve quality of life (QOL) and finally reduce patient mortality. Recently, Silverberg, et al. created a novel clinical entity of Cardio-Renal Anemia (CRA) syndrome, in which anemia plays a key role for worsening both CKD and cardiac performance in a vicious circle. An appropriate and vigorous treatment of anemia has now been accepted to terminate or weaken the circle. Recently, two large-scaled randomized controlled trials were reported, being the CREATE (cardiovascular risk reduction by early anemia treatment with epoetin beta) study and the CHOIR (correction of hemoglobin and outcomes in renal insufficiency) study. They demonstrated that early initiation of ESA treatment and targeting at higher hemoglobin level (near normal level) failed to show the lowering effects for cardiovascular events as compared to a group in which Hb targeting was lower (sub-normal level) in pre-dialysis CKD patients. While there has been many argues in these reports especially about baseline patients characteristics, being a quite high incidence of severe cardiovascular co-morbidity. Thus, further evidences should be accumulated to resolve a proper target level of Hb in ESA treatment.