Efficacy of cerebral thrombolysis in an extended 'time window'

Cerebral systemic thrombolysis (i.v. thrombolysis) with tissue-type plasminogen activator (rt-PA) is the only proven medical therapy for ischaemic stroke. The use of i.v. thrombolysis up to 4·5 h from stroke onset was approved in certain countries in 2008, but its safety and efficacy have not been fully determined to date.

To assess the long-term outcome and complication rate of i.v. thrombolysis performed in the extended 'time window'.

The study included 403 ischaemic stroke patients consecutively treated with i.v. thrombolysis from 2006 to 2012 at three comprehensive stroke centres in Poland. The long-term outcome and the haemorrhagic complications' (HC) rate were compared between subgroups of patients treated within 3 vs. 3-4·5 h from stroke onset.

About 132 (32·75%) patients were treated between 3 and 4·5 h from stroke onset. Neurological deficits tended to be more severe in patients treated ≤3 than in those treated 3-4·5 h (National Institutes of Health Stroke Scale, NIHSS 12 vs.10 points; P = 0·053); however, the ratio of patients with a favourable outcome (mRS 0-2 points) and mortality did not differ between the two groups (53·9 vs. 58·3, P = 0·39 and 17·7 vs. 21·2, P = 0·39, respectively). The rate of HC also did not differ between the two groups (18·8% vs. 15·1%, P = 0·46).

The efficacy of i.v. thrombolysis routinely performed in an extended 'time window' is not reduced when compared to procedures performed within 3 h from symptom onset.