Abstract WP271: Cerebral Small Vessel Disease Influences Computed Tomography Perfusion Mismatch in Acute Ischemic Stroke

Background and Purpose: Cerebral small vessel disease (SVD) is a well-recognized determinant of outcomes after acute ischemic stroke (AIS). Core–penumbra mismatch assessed by computed tomography perfusion (CTP) is a key criterion for reperfusion therapy, yet the influence of SVD on this mismatch remains unclear. We investigated whether SVD burden differs between AIS patients with and without CTP-defined mismatch. Methods: We retrospectively identified consecutive AIS patients admitted to a comprehensive stroke center from November 2013 to March 2025. Inclusion criteria were: (1) admission within 24 hours of onset; (2) CTP performed on admission; (3) MRI obtained during hospitalization; and (4) a symptomatic ischemic lesion in the middle cerebral artery (MCA) territory. Cerebral blood volume (CBV) reduction and mean transit time (MTT) prolongation on CTP were scored using the Alberta Stroke Program Early CT Score (ASPECTS), yielding CBV-ASPECTS and MTT-ASPECTS. CTP mismatch was defined as CBV-ASPECTS minus MTT-ASPECTS > 0. SVD burden was graded by Fazekas deep white matter hyperintensity (DWMH; 0–3), periventricular hyperintensity (PVH; 0–3), and cerebral microbleeds (CMBs; 0, 1–2, 3–10, >10; scored 0–3). ROC analyses identified optimal cutoffs for biomarkers associated with absence of mismatch, which were incorporated into a point-based predictive score. Results: Of 969 screened patients, 81 met all criteria (55 68% male; median age, 73 years; median NIHSS score, 5). CTP mismatch was observed in 55 (68%). Compared with the mismatch group, the no-mismatch group had higher CMB grades (median 1 vs 0; p=0.023) and higher PVH grades (median 2 vs 1; p=0.022), while DWMH grade showed no significant difference (median 1 vs 1; p=0.089). ROC analyses identified CMB grade ≥1 and PVH grade ≥2 as optimal thresholds; each criterion contributed 1 point to the predictive score. This score achieved an AUC of 0.69 (95% CI, 0.57–0.81; p=0.005) for predicting absence of mismatch. Conclusions: A higher burden of SVD—particularly elevated CMB and PVH grades—is associated with absence of CTP-ASPECTS mismatch in AIS. These findings suggest that SVD may alter perfusion dynamics and influence eligibility and response to reperfusion therapy.