Prolonged Venous Transit Is Associated with Unfavorable Functional Outcomes in Large-Core Stroke

ABSTRACT BACKGROUND AND PURPOSE: Large core acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) is associated with high rates of disability despite mechanical thrombectomy (MT). Prolonged venous transit (PVT), a marker of impaired venous drainage on CT perfusion, has emerged as a potential prognostic indicator, but its role in large core AIS-LVO remains unclear. We aimed to test the hypothesis that PVT is independently associated with unfavorable functional outcomes in patients with large core AIS-LVO. MATERIALS AND METHODS: We conducted a retrospective cohort study using data from consecutive patients with AIS-LVO and large ischemic core volumes (ASPECTS <6 or relative cerebral blood flow < 30% volume ≥50 mL; per SELECT-2 trial definition) between September 1, 2016 and September 2, 2024. PVT was assessed on pretreatment CT perfusion based on qualitative time-to-maximum (Tmax) maps and defined as Tmax ≥10 seconds in the superior sagittal sinus or torcula. The primary outcome was unfavorable functional recovery at 90 days, defined as a modified Rankin Scale (mRS) score of 4-6. RESULTS: 100 patients met inclusion criteria, and 41 (41%) had PVT. Unfavorable functional outcomes were more frequent in the PVT+ group (59% vs. 37%, p=0.036). Multivariable analysis confirmed that PVT was independently associated with unfavorable outcomes (adjusted OR 4.07, 95% CI 1.15-14.4, p=0.03), even after accounting for penumbra size (Tmax >6s) and large core volumes (rCBF <30%). Other predictors included older age (adjusted OR 1.07, 95% CI 1.02 to 1.11, P=0.003), higher admission NIHSS (adjusted OR 1.16, 95% CI 1.05 to 1.29, P=0.005), and larger rCBF <30% volume (adjusted OR 1.02, 95% CI 1.00 to 1.04, P=0.032). CONCLUSIONS: PVT is independently associated with unfavorable outcomes in patients with large core AIS-LVO. These findings suggest PVT may serve as a prognostic marker, warranting further investigation and validation in larger prospective studies to guide treatment decisions in this high-risk population.