Their study found that patients treated with TPA within three hours after a stroke caused by a blood clot in the brain are less likely to be severely disabled a year afterward.
A survey last year found that many doctors were afraid to use TPA because of the danger that it can worsen strokes that are caused not by clots but by bleeding directly into the brain.
The Food and Drug Administration approved TPA, or tissue plasminogen activator, for stroke treatment in 1995 after a three-month study showed that it saves lives. The latest study was a one-year follow-up involving 312 patients who got TPA and 312 who got a placebo.
The findings were reported by Dr. Thomas Kwiatkowski of Long Island Jewish Medical Center and doctors at eight other U.S. hospitals. The clot-dissolving medicine is the only drug approved for treating strokes.
The results after a year were about the same as they were at three months. For every 100 stroke patients treated with TPA, at least eleven who otherwise would have had died or had severe problems will come through with few or no symptoms.
The drug has to be given within three hours after a stroke, but after a CAT scan has been done to make sure that the stroke was caused by a blood clot.