Association of plasma fibrinogen concentration with vascular access failure in hemodialysis patients

Abstract

Background. Elevated plasma fibrinogen is an important risk factor for coronary artery disease in the general population and patients with chronic renal failure. High plasma fibrinogen may trigger thrombus formation in arteriovenous fistulas. We performed a prospective, cohort study to evaluate the association of plasma fibrinogen concentration with vascular access failure in patients undergoing long-term haemodialysis. Methods. Between September 1989 and October 1995, 144 patients underwent a vascular access operation. In March 1997, 102 patients (56 M, 46 F) who had been followed up for more than 18 months (median; 37 months, range; 18-102 months) were included in the study. The median age of the patients was 52 years (range; 19-78 years). In 35 patients, renal disease was secondary to diabetes mellitus. The type of vascular access was a polytetrafluoroethylene (PTFE) graft in 17 patients. Seventy-seven patients received recombinant human erythropoietin (r-HuEPO) therapy during the follow-up period. Plasma fibrinogen, albumin, total cholesterol, hematocrit, platelets and creatinine were measured at the time of operation. Vascular access failure was defined as the occurrence of complications requiring transluminal angioplasty, thrombolytic therapy or surgical repair. Results. Thirty-eight patients had at least one vascular access failure and the incidence was 0.3 (range; 0-2.4) episodes per patient-year. The survival rate of vascular access was 78% (native fistula; 80%, PTFE graft; 71%) after 12 months and 70% (native fistula; 73%, PTFE graft; 51%) after 24 months. Older age, a PTFE graft, r-HuEPO therapy, higher hematocrit, lower albumin and higher fibrinogen levels were significantly associated with vascular access failure, whereas gender, diabetes mellitus, total cholesterol and platelet count were not. Plasma fibrinogen was inversely correlated with albumin (r = -0.38, P = 0.001). The cumulative vascular access survival was significantly lower in patients with high plasma fibrinogen levels (≥ 460 mg/dl) compared with patients with low levels (< 460 mg/dl) (P = 0.007). Independent risk factors for vascular access failure analysed by Cox's proportional hazards model were older age (RR; 1.36 by 10-year increment), higher fibrinogen level (RR; 1.20 by 100 mg/dl increment), PTFE graft (RR; 2.28) and r-HuEPO therapy (RR; 3.79). Conclusion. High plasma fibrinogen level is an independent risk factor for vascular access failure in haemodialysis patients.