Managing a fateful alliance: anaemia and cardiovascular outcomes

Cardiovascular disease (CVD) is a significant complication in chronic kidney disease (CKD) and a major cause of death in dialysis patients. Clinical studies have shown that anaemia is associated with reduced survival in patients with renal disease, heart failure or both. There is also evidence that, even in otherwise healthy individuals, anaemia is independently associated with an increased risk of CVD. The body adapts to anaemia by increasing cardiac output, which may result in cardiac remodelling and progression of left ventricular (LV) growth. Indeed, low haemoglobin (Hb) has been identified as an independent risk factor for LV growth in CKD patients, suggesting that there is a direct link between anaemia and adverse cardiac outcomes. This suggests that correction of anaemia with recombinant human erythropoietin (rhEPO; epoetin) may improve prognosis. Partial correction of anaemia produces partial regression of LV hypertrophy, while complete correction of anaemia can help to prevent LV dilatation in haemodialysis patients with normal LV volumes. Moreover, in non-dialysis patients with advanced CVD, pilot studies showed that a moderate increase in Hb improved cardiac function and reduced hospitalization rates. In addition, consistent epoetin treatment before the start of dialysis was associated with a reduced risk of developing cardiac disease in CKD patients. In contrast, in dialysis patients with advanced cardiac disease, Hb normalization increased mortality risk. Therefore, early correction of anaemia appears important. The Cardiovascular risk Reduction by Early Anaemia Treatment with Epoetin P (CREATE) study is investigating whether this approach is associated with a measurable reduction in cardiovascular risk.