The left panel of this angiography shows thrombosis of the right carotid artery such as might occur in a patient who presents to the emergency department with an acute symptomatic ischemic stroke. The right panel demonstrates the return of vascular flow following successful thrombolysis, as might occur after the patient is treated with intravenous alteplase within 180 minutes of stroke onset.
Post-thrombolytic therapy, this patient is most likely to have:
A. an asymptomatic intracranial hemorrhage at 36 hours
B. an improved functional outcome at 3 months
C. an increased risk of all-cause death at 3 months
D. an increased risk of all-cause death at 6 months
Answer and critique
Answer: B. An improved functional outcome at 3 months
While controversial, most internists, neurologists, and critical care intensivists support giving the t-PA agent alteplase within 3 hours of an acute symptomatic ischemic stroke, as do most (not all) guidelines, including strong recommendations from the American College of Chest Physicians, the American College of Emergency Physicians/American Academy of Neurology, and the American Heart Association/American Stroke Association. They believe there is high quality evidence that successful thrombolysis within 3 hours may increase functional independence without affecting overall mortality at 3-6 months, although there is an associated increased risk of symptomatic and fatal intracranial hemorrhage within 7 days. Note that asymptomatic intracranial hemorrhage is not a common outcome measure in studies of this type.
In contrast, t-PA given 3-4.5 hours after stroke onset increases the risk of symptomatic and fatal intracranial hemorrhage within 7 days and might increase 90-day mortality while the effect on improving functional outcomes is uncertain and inconsistent across trials. Even less effective, t-PA given > 4.5 hours after stroke onset may increase risk for fatal intracranial hemorrhage within 7 days and may increase 90-day mortality without increasing likelihood of functional independence (see Table).