Intravenous Thrombolysis Guided by Perfusion CT with Alteplase in >4.5 Hours from Stroke Onset.

Introduction:The benefit of intravenous thrombolysis (IVT) in wake-up stroke (WUS), stroke of unknown time of onset (SUKO), or when time exceeds 4.5 h from last-seen-normal (LSN) guided by CT perfusion (CTP) or MRI has been recently suggested. However, there is limited information of IVT in those patients in real-world studies.Objective:Our aim was to evaluate safety and efficacy of IVT selected by CTP in patients with WUS, SUKO, or stroke of time onset beyond 4.5 h.Material and Methods:We studied a prospective cohort of patients who underwent IVT from January 2010 to December 2017. Two groups were defined: standard of care group (SC) included patients with time onset <4.5 h and CTP group included patients with WUS, SUKO, or onset beyond >4.5 h from LSN with penumbra area in CTP. We evaluated baseline characteristics, functional outcomes according to modified Rankin Scale (mRS) at discharge and at 90 days, and intracranial hemorrhages rates.Results:657 patients were studied: 604 (92%) were treated in the SC group and 53 (8%) in the CTP group. The mean NIHSS score was 9.8 in the CTP group versus 13 in the SC group (p= 0.001). Seventeen patients in the CTP group (32.1%) received bridging therapy with mechanical thrombectomy (MT). Last time seen well-to-needle time was 538 versus 155 min (p< 0.001). The incidence of symptomatic intracranial hemorrhage was equal in both groups (3.8 vs. 3.8%,p= 1). Good functional outcome (mRS < 2) was achieved in both groups (72 vs. 60.4%,p= 0.107).Conclusions:IVT in patients with WUS, SUKO, or stroke beyond >4.5 h from LSN, with salvageable brain tissue on CTP, seems to be safe and has similar functional outcomes at 90 days to the standard therapeutic window, even when combined with MT.