Perioperative Cognitive Decline in Verbal Associative Memory Following Carotid Revascularization and Subsequent Risk of Adverse Events: Clinical Significance of the Standard Verbal Paired Associate Learning Test (S-PA)

Background/Objectives: This study aimed to explore whether perioperative changes in cognitive function following carotid artery revascularization, including carotid endarterectomy (CEA) and carotid artery stenting (CAS), are associated with subsequent clinical outcomes, focusing specifically on the Standard Verbal Paired Associate Learning Test (S-PA). Methods: This prospective, single-center study enrolled 69 patients who underwent CEA or CAS between June 2018 and June 2024. Neuropsychological assessments (Raven’s Colored Progressive Matrices (RCPM), Kohs Block Design Test for IQ (Kohs-IQ), the Trail Making Test (TMT)-A/B, and the Standard Verbal Paired Associate Learning Test (S-PA)) were conducted preoperatively and within seven days postoperatively. Patient characteristics and diagnostic imaging results, including magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and single-photon emission computed tomography (SPECT), were evaluated. Multivariate Cox proportional hazards models and Kaplan–Meier survival analyses were used to identify predictors of adverse outcomes, defined as recurrent stroke, restenosis, or mortality, during outpatient follow-up. Results: Fifteen patients experienced adverse outcomes during follow-up. Perioperative neuropsychological assessment showed that 36 patients experienced S-PA decline, indicating a tendency towards lower mean cerebral blood flow. Receiver operating characteristic (ROC) curve for perioperative ΔS-PA decline associated with adverse outcomes. The area under the curve (AUC) was 0.728. The optimal cutoff determined by the Youden index was a decline of 2 points (ΔS-PA ≤ −2), yielding a sensitivity of 73.3% and specificity of 68.5%. In a time-to-event analysis, S-PA decline was associated with adverse outcomes in an unadjusted analysis. A similar trend was observed in limited multivariable models; however, effect estimates were imprecise (HR = 4.01, 95% CI: 1.01–15.91, p = 0.048). Conclusions: This study indicates that perioperative decline in S-PA may reflect underlying cerebrovascular vulnerability and may be associated with subsequent adverse outcomes. However, given the limited number of events and potential for residual confounding, these findings should be interpreted with caution. Larger multicenter studies are required to validate these findings.