The CRP/albumin ratio: a novel predictor of in-stent restenosis after carotid artery stenting

Abstract Background In-stent restenosis (ISR) remains a potential problem and raises concerns about the long-term safety and efficacy of carotid artery stenting (CAS). As inflammation has a pivotal role in the pathogenesis of ISR, a novel and more sensitive inflammatory marker, CRP/albumin ratio (CAR) may be used to predict ISR in patients undergoing CAS. Purpose The present study aimed to assess the predictive value of preprocedural C-reactive protein/albumin ratio (CAR) for ISR after CAS. Method In this retrospective study, 206 patients who underwent successful CAS procedure in a tertiary heart centre were included. For each patient, both C-reactive protein (CRP) and serum albumin were determined before the index procedure. The CAR was calculated by dividing serum CRP by serum albumin level. The main end-point of the study was ISR during long-term follow-up. Results ISR developed in 34 (16.5%) out of 206 patients after a mean follow-up of 24.2±1.5 months. The CAR was significantly elevated in patients with ISR compared to those who were not (0.99 [1.3] vs. 0.15 [0.2], p<0.01, respectively). In a multivariate Cox regression analysis, the CAR was an independent predictor of ISR (HR: 1.85, 95% CI: 1.29–2.64, p<0.01). A ROC curve analysis revealed that the optimal value of CAR in predicting ISR was >0.53 with a sensitivity of 100% and a specificity of 97.1% [area under curve (AUC) 0.98, p<0.001]. Conclusion The present study demonstrated that CAR, a new inflammatory-based index, is a strong independent predictor of ISR after CAS. As a simple and easily accessible parameter, this index may be used for the assessment of ISR in patients who are treated with CAS. Funding Acknowledgement Type of funding source: None