Prognostic Nutritional Index as a Predictor of Prognosis in Patients with Chronic Limb Threatening Ischemia Who Underwent Endovascular Revascularization Therapy

Background : Patients with chronic limb-threatening ischemia (CLTI) have poor prognosis. Prognostic nutritional index (PNI) is an established independent predictor of adverse outcome in various chronic illnesses. The use of PNI in patients with CLTI has not been studied. To evaluate the impact of PNI on 12-month adverse cardiovascular and limb outcomes in CLTI patients after endovascular revascularization therapy (ERT). Methods : 270 consecutive patients with CLTI (mean age 73.7 ± 11.9 years; 53% male) who underwent ERT at a single tertiary referral hospital between January 2009 and October 2016 were prospectively enrolled and analyzed. Patients were grouped by tertiles of PNI (lowest ≤ 37.5; middle 37.6 e 45.5; and highest > 45.5) at baseline de fi ned as 10 £ serum albumin (g/dL) þ 0.005 £ total lymphocyte count (per mm 3 ). Composite endpoint including all-cause mortality and amputation was considered as primary endpoint. All-cause mortality and amputation were also analyzed individually as secondary endpoints at 12-months. Multivariate Cox proportional hazards regression analyses were performed. Results : Mean PNI of the 3 groups were 32.8, 42.2 and 50.4 respectively. Co-morbidities such as end-stage renal failure, heart failure and Rutherford classi fi cations 6 were signi fi cantly more prevalent in the lowest PNI tertile (all P < 0.05). Patients in the highest PNI tertile was associated with lowest incidence of 12-month composite endpoint (9.9%), all-cause mortality (7.7%) and amputation (3.3%) compared to those in the middle (27.0%, 22.5%, 9.0%) and lowest (52.2%, 47.8%, 16.7%) respectively, and reached statistical signi fi cance (p < 0.05). Multivariate analysis demonstrated high PNI was an independent protective predictor of composite endpoint (adjusted Hazards Ratio (HR) 0.26, 95% con fi dence interval (CI): 0.12 e 0.57) and all-cause mortality (adjusted HR 0.20; 95% CI: 0.09 e 0.49). Kaplan-Meier analysis revealed that higher PNI was signi fi cantly associated with better prognosis with regard to amputation, all-cause mortality and primary composite endpoint (log rank < 0.05). Conclusions : Our results demonstrated that higher nutritional status de fi ned by prognostic nutritional index (PNI) predicted lower all-cause mortality and amputation rates in chronic limb-threatening ischemia patients after endovascular revascularization therapy.