Predictive significance of the prognostic nutritional index for in-stent restenosis following carotid artery stenting

Background: Malnutrition and inflammation both have important impacts on medical outcomes of individuals treated by carotid artery stenting (CAS). However, their impact on the occurrence of carotid in-stent restenosis (ISR) is not sufficiently understood. Aims: We explored the association of immune-nutritional status, as measured by the Prognostic Nutritional Index (PNI), with ISR in individuals who had undergone CAS. Methods: This retrospective single-center study focused on individuals diagnosed with severe carotid artery disease who were treated with CAS in the years 2016-2021 at a tertiary healthcare facility. A total of 819 patients were considered in the analysis. Their cases were subdivided into groups in line with the presence or absence of ISR as confirmed by angiography conducted after ultrasonographic follow-up assessments. Results: In 24 months of follow-up, ISR was observed angiographically in 35 patients (4.3%). Total cholesterol (odds ratio [OR], 1.011; 95% CI [confidence interval], 1.003-1.019; P = 0.009), stent overlap (OR, 5.424; 95% CI, 1.026-28.670; P = 0.047), residual stenosis (OR, 47.930; 95% CI, 16.280-141.110; P <0.001), and PNI (OR, 0.846; 95% CI, 0.782-0.915; P <0.001) independently served as predictors of ISR. Based on the results of the receiver operating characteristic analysis, when the cut-off threshold of the PNI score was accepted as 39.5, the score could predict ISR with sensitivity of 83% and specificity of 77%. (area under the curve [AUC] 0.808; 95% CI, 0.754-0.869; P <0.001) Conclusion: This research demonstrates the existence of a meaningful independent correlation between PNI and ISR in individuals treated with CAS. Malnutrition and inflammation, parameters, easily evaluated with the help of the PNI, could be considered as simple and practical indicators for ISR in cases of CAS treatment.