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

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.

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.

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.

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).

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.