The use of intravenous recombinant tissue plaminogen (rt-PA) to treat stroke was initially restricted to treatment in patients under the age of 80 and when started within 3 hours of symptom onset. Treatment with rt-PA can cause lysis of intravascular clots that cause brain ischemia and restore blood flow to affected areas before permanent injury results. The window for treatment was then extended to 4.5 hours after symptom onset, but its use was still restricted to patient less than 80 years of age.
The Third International Stroke Trial (IST-3) looked at rt-PA use in patients over 80 years of age and found that treatment was beneficial for elderly patients who receive treatment within 4.5 hours of symptom onset. The primary outcome used to measure the effectiveness of treatment was the proportion of patients living independently at 6 months after the initial stroke. There was a net benefit of treatment of strokes with rt-PA in elderly patients over age 80.
The outcome measure used to determine whether rt-PA treatment was successful was the patient's independence in daily living. The study showed that there was less disability at 6 months in patients older than 80 who received rt-PA treatment similar to the benefits of treatment that has been shown in younger patients.
The failure to timely diagnose and treat stroke with rt-PA causes irreversible brain injury. Although age used to be a consideration in determining whether or not to provide treatment with rt-PA, this study strongly supports the use of thrombolytics in patients of all ages if the patient presents within 4.5 hours of the onset of symptoms. Instead of deciding if treatment should be given, emergency room physicians should routinely recommend treatment to most patients and only look to identify those few patient who should not be given treatment.