Time to Treatment With Intravenous Tissue Plasminogen Activator and Outcome From Acute Ischemic Stroke

NTRAVENOUS (IV) TISSUE-TYPE PLASminogen activator (tPA) is a treatment of proven benefit for select patients with acute ischemic stroke as long as 4.5 hours after onset. 1,2Available evidence suggests a strong influence of time to therapy on the magnitude of treatment benefit.In stroke animal models, time to reperfusion is a dominant determinant of final infarct volume. 3In human patients, imaging studies show the volume of irreversibly injured tissue in acute cerebral ischemia expands rapidly over time, typically consuming 2 million additional neurons per minute until reperfusion is achieved. 4Pooled data from IV tPA clinical trials indicate that therapeutic benefit of tPA is greatest when given very early after ischemic stroke