Geriatric Nutritional Risk Index is an Independent Predictor for Long-term Outcome in Patients Undergoing Open Bypass Not Only for Critical Limb Ischemia but Also for Intermittent Claudication

Introduction - Geriatric Nutritional Risk Index (GNRI) has been reported as an independent predictor for prognosis in patients with critical limb ischemia (CLI) following endovascular treatment (EVT)1. While, there have been no report regarding the association between the long-term outcome and GNRI in patients undergoing open bypass for CLI and intermittent claudication (IC). The purpose of this study is to examine whether or not GNRI is a significant predictor for long-term outcome in patients undergoing infrainguinal bypass not only for CLI but also for IC. Methods - In the period from 1991 to 2017, 427 and 239 patients underwent infrainguinal bypass for CLI and IC, respectively. The patients with a history of major amputation in the contralateral limb or open bypass in the either limb were excluded. They were divided into 3 groups based on the preoperative GNRI; Group I, no risk group (GNRI: >98); Groups II, low risk group (GNRI: 92 to <98); Group III, moderate or major risk group (GNRI: <92). Amputation-free survival (AFS) was set as an endpoint. In this study, AFS was defined as survival without major amputation of the either limb and up to 5 years’ worth of data were analyzed. The 5-year AFS rates of three groups were calculated by Kaplan-Meier’s method, and a Cox proportional hazard regression analysis was performed to detect predictors of AFS. As variables for a multivariate analysis in patients with IC, GNRI, age, gender, preoperative ankle-brachial pressure index (ABPI), anemia (hemoglobin <10g/dl), hypertension, diabetes mellitus, ischemic heart disease, stroke, dyslipidemia, chronic obstructive pulmonary disease (COPD), end-stage renal disease (ESRD), and smoking history were adopted. Ambulatory state and tissue loss were added to the above-mentioned 13 variables for an analysis in patients with CLI. Results - In patients with CLI, AFS rates of Group I, II, and III were 88%, 78%, and 74% at one year, 72%, 53%, and 44% at 3 years, and 59%, 38%, and 19% at 5 years, respectively. Group I was significantly superior to Group II (p=0.002) or Group III (p<0.001), and Group II was significantly superior to Group III (p=0.024) on AFS. In patients with IC, AFS rates of Group I, II, and III were 99%, 96%, and 86% at one year, 94%, 86%, and 74% at 3 years, and 84%, 68%, and 57% at 5 years, respectively. Group I was significantly superior to Group II (p=0.014) or Group III (p<0.001) on AFS, and there was no significant difference between Group II and Group III on AFS (p=0.192) (Figure). A multivariate analysis showed GNRI (hazard ratio [HR], 0.72 per 10; 95% confidence interval [CI], 0.61-0.86 per 10, p<0.001), age (HR, 1.28 per 10; 95% CI, 1.05-1.56 per 10, p=0.013), ABPI (HR, 0.92 per 0.1; 95% CI, 0.88-0.97 per 0.1, p=0.001), and ESRD (HR, 2.20; 95% CI, 1.53-3.15, p<0.001) to be significant predictors for AFS in patients with CLI and GNRI (HR, 0.62 per 10; 95% CI, 0.43-0.89 per 10, p=0.011), age (HR, 2.30 per 10; 95% CI, 1.41-3.87 per 10, p<0.001), and COPD (HR, 2.58; 95% CI, 1.05-5.72, p=0.039) to be significant predictors for AFS in patients with IC. Conclusion - GNRI was an independent predictor for 5-years’ AFS in patients with CLI or IC. Patients with no nutrition-related risk can be expected to be long-life without loss of either limb following open surgery for ischemic symptoms due to peripheral arterial disease. References1.Shiraki T, et al. The geriatric nutritional risk index is independently associated with prognosis in patients with critical limb ischemia following endovascular therapy. Eur J Vasc Endovasc Surg (2016) 52, 218-224