The role of preoperative cart score as predictor of renal functional decline after partial nephrectomy

Introduction: Partial nephrectomy (PN) may be associated with a decreased risk of functional loss compared to radical nephrectomy (RN), but a significant functional decline may still occur. CART score is a novel scoring system able to predict functional decline after PN. Aim of this study was to assess the validity of CART score in an internal cohort of patients. Materials and methods: We enrolled 67 patients with pre-operative estimated glomerular filtration rate (eGFR) >60 ml/min/1.73 m2 by CKD-EPI who underwent PN in a single institution. Data were prospectively collected and retrospectively analyzed. For each patient CART score was determined considering the value of pre-operative CRP, age at surgery, race and tumor size and patients were divided into 3 categories: low (4–6), intermediate (7–9) and high (>10) score. Statistical analysis were conducted using Fisher exact test, T test, and Mann-Whitney U test. Univariate and multivariate analyses were performed. Results: Patients were assigned as follows: 46 to low-CART, 20 to intermediate-CART and 5 to high-CART score. Comparing to low CART, high CART patientswere at higher risk of developing post-operative CKD stage worst than IIIb (p = 0.0045); median age and clamping time were significantly higher in this group (p = 0.008; p = 0.005). No differences were observed for ischaemia (warm vs. cold), presence of diabetis mellitus or hypertension, BMI, Charlson score and mean follow-up. ROC analysis revealed AUC of 0.9. At multivariate analysis high CART score resulted as the only independent predictor of post-operative eGFR <45 ml/min/1.73 m2 (OR 14.01, 1.32–22.9 CI 95%; p = 0.04). Conclusions: CART score is a a low time-consuming and a good costeffective tool. In our cohort of study a high CART score represented a strong predictor of post-operative CKD stage worst than IIIb. CART score may play an adjunctive role in pre-operative counselling and clinical decision making of patients eligible for PN.