Estimated Glomerular Filtration Rate (eGFR) as a Predictor of Outcome after Infrainguinal Bypass in Patients with Critical Limb Ischemia

Abstract

Objectives Renal insufficiency is a risk factor for poor outcome after infrainguinal bypass in patients with critical limb ischemia (CLI). Estimated glomerular filtration rate (eGFR) takes age, gender and body size into account and therefore represents actual renal function more accurately than serum creatinine level alone. The aim of this study was to determine the impact of different stages of renal insufficiency on outcome and to assess the prognostic significance of eGFR in patients with CLI. Material and methods 603 patients with CLI who underwent infrainguinal bypass between January 2002 and December 2005 at our institution were included in this retrospective study. We estimated GFR using the Modification of Diet in Renal Disease (MDRD) Study equation. Survival, leg salvage and amputation-free survival were calculated using Kaplan–Meier method. Cox regression analysis was performed to calculate hazard ratios for different outcome variables. Results Adjusted hazard ratio (HR) of mortality, limb loss and limb loss and/or death for eGFR <30 ml/min/1.73 m 2 versus serum creatinine >200 μmol/l was 4.0 (95% CI 2.22–7.39) vs 3.5 (95% CI 1.82–6.84), 6.5 (95% CI 2.71–15.59) vs 6.2 (95% CI 2.47–15.56) and 4.0 (95% CI 2.40–6.63) vs 3.6 (95% CI 2.03–6.25), respectively. Conclusion Estimated GFR is better predictor of survival, leg salvage and amputation-free survival than serum creatinine alone. eGFR <30 ml/min/1.73 m 2 is independent risk factor for all three outcome endpoints.