Brain image close-upThe clot-busting drug alteplase may help salvage brain tissue even when it is given hours beyond the three-hour window after stroke onset or to patients suffering wake-up strokes, according to research presented at the American Stroke Association’s International Stroke Conference 2016.

Alteplase is a tissue plasminogen activator (tPA) which breaks up stroke-related blood clots. It is approved to treat patients who arrive at the emergency room within three to 4.5 hours of stroke onset but many patients get to the emergency room hours later and some have strokes while they’re sleeping, so it’s difficult to pinpoint when symptoms started.

Researchers studied 105 ischemic (clot-caused) wake-up stroke patients and patients whose strokes started 4.5 to nine hours before treatment to determine whether salvageable brain tissue was still present. Wake-up stroke patients, in general, had more tissue loss from their strokes than non-wake-up stroke patients. However, both groups have a substantial amount of salvageable tissue, which is at risk of dying if blood flow is not restored promptly.

Researchers said that administering the clot-busting drug 4.5 to nine hours after symptom onset or to those who woke up with stroke has the potential to be beneficial given the substantial presence of the therapeutic targets of viable tissue.

This is an ongoing study looking at whether administering alteplase to these patients’ leads to long-term health benefits, researchers said.