Association between pericarotid fat attenuation index and clinical outcomes of symptomatic cerebral small vessel disease

Abstract

Background: Pericarotid fat attenuation index (FAI) could serve as a surrogate marker of localized inflammation and was associated with cerebrovascular ischemic events. This study aimed to investigate correlations between FAI assessed on carotid computed tomography angiography (CTA) and clinical outcomes of symptomatic cerebral small vessel disease (CSVD). Methods: A total of 202 symptomatic CSVD patients who underwent carotid CTA and brain magnetic resonance imaging (MRI) were included. Clinical outcomes were evaluated using modified Rankin Scale (mRS) at 90 days after acute event. Perivascular FAI surrounding extracranial internal carotid artery (ICA), CSVD neuroimaging markers and carotid CTA variables were collected. Six predictive models were used to assess the incremental predictive value of FAI with respect to total CSVD burden, carotid stenosis degree and plaque type. Receiver operating characteristic (ROC) curves were used and areas under the curve (AUCs) were compared. Results: A total of 123 patients with poor outcomes and 79 with good outcomes were analyzed. The mean and maximum FAI values in the poor outcome group were higher than those in the good outcome group (mean FAI: −64.47±6.86 vs. −70.86±6.74, P<0.001; maximum FAI: −61.60±7.00 vs. −67.96±7.01, P<0.001). FAI value, total CSVD score and carotid artery stenosis degree were significant independent risk factors for adverse outcomes in symptomatic CSVD patients (all P<0.05). The prediction model with integrated FAI showed enhanced performance with a sensitivity of 65.85% and specificity of 93.67% [AUC =0.863, 95% confidence interval (CI): 0.815–0.912, P<0.001]. Conclusions: In addition to CSVD burden and carotid artery stenosis degree, pericarotid FAI obtained from carotid CTA could provide incremental value for predicting unfavorable functional outcomes, facilitate risk stratification and guide individual treatment in symptomatic CSVD.