Role of type of vascular access in erythropoietin and intravenous iron requirements in haemodialysis.

BACKGROUND Recent data have suggested the existence of a relationship between the use of synthetic vascular accesses and increased erythropoietin (Epo) requirements. The present study aimed to evaluate the possible role of the type of vascular access in both Epo and intravenous (i.v.) iron requirements. METHODS One-hundred-and-seven individuals without recognized causes of Epo resistance, 62 of them undergoing chronic haemodialysis through native arteriovenous fistulae (AVF) and 45 through PTFE grafts, were retrospectively studied (one-year follow-up). Sixty-nine patients, i.e. all but three with a PTFE graft and 27 with native AVF, were taking anti-platelet agents. Doses of i.v. iron and Epo and laboratory parameters were recorded. RESULTS Erythropoietin and i.v. iron requirements were higher in the patients dialysed through PTFE grafts compared with those with native AVF (Epo: 103.8+/-58.4 vs 81.0+/-44.5 U/kg/week, P=0.025; i.v. iron: 178.9+/-111 vs. 125.9+/-96 mg/month, P=0.01). On a yearly basis, the difference in Epo dose represented a total of 94582+/-16789 U Epo/patient/year. Moreover, the patients with PTFE grafts received more red blood cell transfusions than patients with native AVF (P=0.021). No differences between laboratory, dialysis kinetics, demographic or comorbidity parameters were found. The type of vascular access was the best predictor of the requirement of > or =150 U/kg/week Epo (P=0.03). Even though the patients who received anti-platelet therapy required more i.v. iron (167.5+/-103.6 vs. 114.5+/-101.4 mg/month, P=0.008) but not more Epo (P=NS), the possibility of an accessory role of anti-platelet agents in the increased Epo requirements with PTFE grafts cannot be ruled out. CONCLUSIONS The use of a PTFE graft and anti-platelet drugs represents a previously undescribed association related to higher Epo and i.v. iron requirements. The association described herein adds new arguments to the debate concerning the choice of vascular access in chronic haemodialysis patients.