Prognostic Value of NCCT vs. CTP in Assessing Long-term Functional Outcomes in Late-window Mechanical Thrombectomy

Introduction: The DAWN and DEFUSE3 trials demonstrated that mechanical thrombectomy (MT) benefits late-window patients (6-24 hours) with large vessel occlusion (LVO) if specific imaging criteria are met, typically using CT perfusion (CTP) or MRI. However, the added value of CTP over non-contrast CT (NCCT) for predicting long-term outcomes remains uncertain, potentially favoring NCCT as a cost-effective option.

Methods: This retrospective study included 81 patients who underwent late-window MT for M1/ICA occlusions between 2019 and 2024. The primary outcome was functional independence (mRS ≤ 2) at 90 days. ROC analysis was used to evaluate NCCT ASPECTS and CTP core and penumbra values for predictive accuracy, with DeLong’s test applied to compare ROC curves. All statistical analyses were conducted in RStudio (version 2024.09.0).

Results: The cohort’s mean age was 67.1 ± 16.6 years, with a balanced gender distribution, with a majority of white and black patients. Patients presented with an average NIHSS score of 17 ± 6.7, and 28.2% achieved mRS 0-2 at 90 days. ROC analysis revealed AUCs were 0.550 for NCCT ASPECTS, 0.565 for CTP core, and 0.612 for CTP penumbra, indicating weak to moderate predictive value. Pairwise comparisons revealed no significant differences among these modalities (ASPECTS vs. core: p = 0.838; ASPECTS vs. penumbra: p = 0.510; core vs. penumbra: p = 0.628), suggesting that CTP did not meaningfully outperform NCCT for predicting long-term outcomes.

Conclusion : These findings suggest that NCCT and CTP offer comparable predictive value for long-term functional outcomes in late-window MT for anterior circulation LVO. This has significant clinical implications, especially in settings where advanced imaging resources are limited. Broader adoption of NCCT could streamline decision-making and increase access to MT in late-window LVO patients. Further multicenter studies with larger patient cohorts are essential to validate these results and refine clinical workflows to optimize outcomes.