Background-Periprocedural outcome has been extensively investigated in patients undergoing carotid artery stenting.However, risk factors contributing to long-term mortality have not been comprehensively assessed. We aimed to establish a validated clinical risk score for long-term mortality in patients after carotid artery stenting. Methods and Results-Two independent cohorts after successful carotid artery stenting (602 and 552 patients) were prospectively investigated. Multivariable Cox regression and bootstrap variable selection were used to select the bestfitting multivariable model. The mortality rate was 35% in the derivation and 39% in the validation cohort during a median follow-up of 6.5 and 7.4 years, respectively. The following variables were identified as most robust risk factors in the derivation cohort: age, heart failure, diabetes mellitus, relative lymphocyte count, prothrombin time, peripheral artery disease, and contralateral carotid occlusion. A weighted multimarker risk score yielded an area under the receiver operating characteristic curve of 0.79 in the derivation (P<0.001) and of 0.69 (P<0.001) in the validation cohort. In comparison, the best area under the receiver operating characteristic curves for single risk factors were 0.67 and 0.63, respectively. For optimal clinical use, a simplified risk score was also developed, which discriminated very well from very low to very high risk. The risk of all-cause mortality ranged from 8% for a score of 1 to 93% for a score of 7 (P<0.001) in the derivation and from 11% to 100% in the validation cohort (P<0.001).
Conclusions-