Kim JT, Fonarow GC, Smith EE, et al. Circulation. 2017;135:128-139.
Study Question: What is the benefit of tissue plasminogen activator (tPA) administration within the first 60 minutes (“golden hour”) after last known well time?
Study Description: This was a retrospective evaluation of the Get with the Guidelines-Stroke Program national registry over a 4.75 year period. Patients were eligible for inclusion if they had an acute ischemic stroke treated with intravenous (IV) tPA within 4.5 hours of last known well time. Patients must have also had a known discharge destination and gender and could not have received experimental treatment.
Results: Over 65,000 patients from 1,456 sites were included. Factors independently associated with receiving tPA within 60 minutes from onset-to-treatment (OTT) were a higher hospital annual volume of tPA-treated cases, non-primary stroke centers, Western US hospitals, severe neurological deficit, arrival during regular weekday hours, and less frequent arrival by Emergency Medical Services ambulance. Shorter time from last known well and increasing age were also associated with higher likelihood of golden hour tPA until age 65. Thereafter, increasing age was associated with decreased frequency of hyperacute thrombolysis. Patients with an OTT of < 60 minutes had increased odds of discharge home, independence in ambulation, freedom from disability, and functional independence. No difference in safety outcomes was seen. When evaluating time-benefit curves, a nonlinear relationship was noted for rates of discharge home as a rapid benefit loss was seen in first 170 minutes. Ambulation at discharge and hospital mortality were linear curves, with 1.4 more deaths per 1,000 treated for every 15-minute delay.
Conclusion(s): In patients with acute ischemic stroke, IV tPA within the first 60 minutes is associated with the best outcomes without a difference in safety.
Perspective: These results highlight the importance of hyperacute treatment of ischemic stroke. While no long-term variables are reported, the lack of difference in safety outcomes reassures the risk:benefit ratio favors treatment within the golden hour. The small percentage of patients who received IV tPA within 60 minutes (1.3%) may highlight the difficulty in strict initiation goals.