Post-licensed 1-year experience of systemic thrombolysis with tissue plasminogen activator for ischemic stroke in a Japanese neuro-unit

In Japan, intravenous thrombolysis with tissue plasminogen activator (tPA) for ischemic stroke within 3h of onset was officially approved in October 2005.

We report initial 1-year clinical experience of intravenous alteplase at 0.6mg/kg in a Japanese neuro-unit.

Twenty patients received intravenous tPA, corresponding to 12% of all ischemic strokes (n=166) and 38% of ischemic strokes within 3h of onset (n=52). The mean age was 68 years old and 15% had pre-morbid dependency with modified Rankin Scale (mRS) of 3 or 4. The median baseline National Institute of Health Stroke Scale score was 19 points (range; 5-37). Average time from stroke onset to tPA delivery was 136 min (range; 87-180). Of 18 (90%) patients receiving pretreatment vascular imaging, 16 (80%) patients had a large arterial occlusion. At 3 months, excellent outcome with mRS of 0 or 1 was 25%, and good outcome with mRS of 0-2 was 35%. One patient (5%) developed symptomatic intracranial hemorrhage within 36 h. Mortality rate was 15%.

Intravenous tPA within 3h was safe and feasible, and possibly effective in clinical practice. The higher stroke severity in our cohort precluded to compare the sufficient effectiveness with clinical trials. In Japan, a post-licensed national surveillance is currently under way.