Derivation and Validation of Risk Score Including Nutritional Status Among Patients With Chronic Limb-threatening Ischemia: Insight From I-PAD NAGANO Registry

PURPOSE: Geriatric nutritional related index (GNRI) is a simple and well-established screening method of nutritional status. We aimed to develop and validate a scoring system including GNRI to predict long-term outcomes in patients with chronic limb-threatening ischemia (CLTI) undergoing endovascular treatment (EVT). MATERIALS AND METHODS: Patients undergoing EVT for symptomatic LEAD from August 2015 to August 2016 were enrolled into the I-PAD NAGANO registry, a prospective, multicenter, observational registry. We identified predictors of amputation-free survival (AFS) at 5 years using Cox proportional hazards regression and developed a risk scoring system. The predictive performance of the risk score was assessed. RESULTS: A total of 126 patients with CLTI were analyzed. Cox multivariate analysis revealed GNRI score <92 points, ≥72 years of age, hemodialysis, heart failure, and anemia to be significant predictors. We developed a 5-item risk score (I-PAD CLTI score) assigning points to each factor based on the magnitude of association with AFS at 5 years. The I-PAD CLTI score showed a c-index of 0.80 for 5-year AFS. Patients with high score (≥7 points, n=50) had an increased risk of AFS at 5 years compared with those with low score (<7 points, n=68) (26.5% vs 72.1%, p<0.001). CONCLUSION: A simple 5-item risk score including nutritional status showed reasonable discriminative and prognostic ability for long-term AFS among patients with CLTI.Clinical ImpactThe I-PAD CLTI score, a simple five-item risk score including nutritional status determined by geriatric nutritional related index, showed reasonable discriminative and prognostic ability for long-term amputation free survival among patients with chronic limb-threatening ischemia. This risk score may be useful for clinicians to accurately predict patient's prognosis and thus identify high-risk patients who may derive the greater clinical benefit from more intensive risk modification. Further research is required to test the clinical utility of risk-score-based treatment approach to improve the prognosis of patients with chronic limb-threatening ischemia.