Abstract TMP95: Infarct Growth During Inter-facility Transfer In An Integrated Stroke Network

Abstract

Background: Perfusion imaging is used to determine eligibility for mechanical thrombectomy (MT) in patients presenting with large vessel occlusion (LVO) in acute ischemic stroke. The utility of CT perfusion (CTP) imaging in spoke hospitals remains controversial. The aim of the study was to compare the imaging parameters, functional and safety outcomes in patients selected for MT based on CTP availability in regional hospitals. Methods: Consecutive adult patients treated for LVO after initially presenting to regional spokes between Jan 2021 to Dec 2021 were included in the analysis. Our standard Acute Stroke Imaging Protocol included CT/CT angiogram. CT perfusion was added to the protocol in April 2021. Demographics, NIHSS, imaging metrics (ASPECTS, CTA collateral score, reperfusion (mTICI 2b/3) rates), hemorrhage (per ECASS III) and functional outcomes (modified Rankin Scale of 0-2 at 90 days) were compared between patients who did vs. did not undergo CTP at regional. Core infarct volume growth and rate (ml/min) was assessed for patients with CTP data both at the regional and at the Comprehensive Stroke Center (CSC). Results: A total of 29 patients met inclusion during the study period. Of these, 14 patients were transferred to CSC for possible MT without CTP at the regional facility and 15 were transferred with CTP at regional. Age (p=0.44), NIHSS (p=0.08) and onset-to-regional facility arrival time (p=0.54) were similar in both groups. For all patients, repeat imaging at the CSC showed significantly decreased ASPECTS (p=0.002) but stable CTA collateral score (p=0.94). For patients who underwent CTP both at the regional facility and CSC, median core infarct volume grew significantly (0[0, 7] ml vs. 7 [0, 14] ml, p=0.022), with a median growth rate of 0 [0, 0.07] ml/min. No patients were excluded from thrombectomy due to core infarct growth. Rates of successful reperfusion (p=0.83) and hemorrhagic transformation (p=0.49) did not differ significantly between the groups. Rates of mRS 0-2 were similar in both groups (p=0.85). Conclusion: Our study suggests that core infarct grows during interfacility transfers without an impact on selection for thrombectomy and outcomes. A larger study is needed to assess the need for repeating perfusion imaging at CSC.