Prediction of Amyloid Positivity in Patients with Subcortical Vascular Cognitive Impairment

Background: Amyloid-beta (A beta) commonly coexists and impacts prognosis in subcortical vascular cognitive impairment (SVCI). Objective: This study aimed to examine the differences in clinical and neuroimaging variables between A beta-positive and A beta-negative SVCI and to propose a prediction model for A beta positivity in clinically diagnosed SVCI patients. Methods: A total of 130 patients with SVCI were included in model development, and a separate cohort of 70 SVCI patients was used in external validation. The variables for the prediction model were selected by comparing the characteristics of the A beta-negative and A beta-positive SVCI groups. The final model was determined using a stepwise method. The model performance was evaluated using the receiver operating characteristic (ROC) curve and a calibration curve. A nomogram was used for visualization. Results: Among 130 SVCI patients, 70 (53.8%) were A beta-positive. The A beta-positive SVCI group was characterized by older age, tendency to be in the dementia stage, a higher prevalence of APOE epsilon 4, a lower prevalence of lacune, and more severe medial temporal atrophy (MTA). The final prediction model, which excluded MTA grade following the stepwise method for variable selection, demonstrated good accuracy in distinguishing between A beta-positive and A beta-negative SVCI, with an area under the curve (AUC) of 0.80. The external validation demonstrated an AUC of 0.71. Conclusions: The findings suggest that older age, dementia stage, APOE epsilon 4 carrier, and absence of lacunes may be predictive of A beta positivity in clinically diagnosed SVCI patients.