Improved stroke risk stratification in carotid atherosclerosis: integrating intraplaque neovascularization into Carotid Plaque-RADS

INTRODUCTION: This study evaluates whether IPN, as assessed by contrast-enhanced ultrasound (CEUS), enhances stroke risk stratification within the Carotid Plaque-RADS framework. METHODS: We conducted a retrospective analysis of 157 stroke patients between July 2020 and January 2021. IPN grade was assessed using CEUS, and patients were categorized based on the Carotid Plaque-RADS. The recurrence-free survival (RFS) rates were calculated, and the incremental value of incorporating IPN grades into Carotid Plaque-RADS was analyzed. RESULTS: During a follow-up period of 35 ± 10 months, 44 out of the 157 stroke patients experienced recurrent strokes. There was significant difference in the incidences of stroke recurrence between IPN Grade 1 and Grade 2 (12.6% vs. 57.4%, p < 0.001). Integration of IPN grading with Carotid Plaque-RADS resulted in disparities in RFS rates between RADS 2 and RADS 3, as well as between RADS 3 and RADS 4 (both P < 0.05), which did not exist in the Carotid Plaque-RADS score alone. Furthermore, significant difference in RFS rates were noted between Carotid Plaque-RADS ≤ 3 patients with IPN Grade 2 and those with IPN Grade 1 (P < 0.001). Among patients initially categorized under Carotid Plaque-RADS ≤ 3, 7.7% (8/104) were accurately reclassified, demonstrating a net reclassification improvement of 12.0% after incorporating IPN grades into the Carotid Plaque-RADS. Additionally, the incorporation of IPN grades with Carotid Plaque-RADS led to a substantial increase in the chi-square value (chi-square difference = 20.62; likelihood ratio test P < 0.001). CONCLUSION: Integration of the presence of IPN Grade 2 into Carotid Plaque-RADS significantly enhanced its ability for stratifying stroke recurrence risk.