Addressing a real-life problem: treatment with intravenous thrombolysis and mechanical thrombectomy in acute stroke patients with an extended time window beyond 4.5 h based on computed tomography perfusion imaging.

Abstract

Acute ischemic stroke treatment with intravenous thrombolysis (IVT) is restricted to a time window of 4.5h after known or presumed onset. Recently, magnetic resonance imaging-guided treatment decision-making in wake-up stroke (WUS) was shown to be effective. The aim of this study was to determine the safety and outcome of IVT in patients with a time window beyond 4.5h selected by computed tomography perfusion (CTP) imaging. We analyzed all consecutive patients last seen well beyond 4.5h after stroke onset treated with IVT based on CTP between January 2015 and October 2018. CTP was visually assessed to estimate the mismatch between cerebral blood flow and cerebral blood volume maps. Early infarct signs were documented according to Alberta Stroke Program Early CT Score (ASPECTS). Safety data were obtained for mortality and symptomatic intracerebral hemorrhage (sICH). Follow-up was assessed with the modified Rankin Scale (mRS). A total of 70 patients fulfilled the inclusion criteria (mean age±SD 77.6±11.5years, 50.0% female). Median National Institutes of Health Stroke Scale score on admission was 8.0 [interquartile range (IQR), 4-14]. The most frequent reasons for an extended time window were WUS (60.0%) and delayed hospital admission (27.1%). Median time from last seen well to IVT was 11.4h. Median ASPECTS was 10 (IQR, 9-10) and CTP mismatch 90% (IQR, 80%-100%). A total of 24 patients (34.3%) underwent additional mechanical thrombectomy. sICH occurred in four patients (5.7%). At follow-up, 49.3% had an mRS score of 0-2 and 22.4% had an mRS score of 0-1. In patients presenting in an extended time window beyond 4.5h, IVT treatment with decision-making based on CTP might be a safe procedure. Further evaluation in clinical trials is needed.