Time Windows for Thrombolysis and Endovascular Treatment in Acute Ischemic Stroke

IV tPA Time Windows

The American College of Chest Physicians recommends administering IV tPA within 3 hours of symptom onset, carrying a Grade 1A recommendation, to improve functional outcomes in patients with acute ischemic stroke 1, 3
The American College of Emergency Physicians provides a Level A recommendation for treatment within the 0-3 hour window to improve functional outcomes in patients with acute ischemic stroke 2
Consider IV tPA between 3-4.5 hours, carrying a Grade 2C recommendation from the American College of Chest Physicians, and apply the ECASS III inclusion/exclusion criteria for this extended window 1, 2, 3

Consider intraarterial tPA within 6 hours for patients with acute ischemic stroke due to proximal cerebral artery occlusions who do not meet eligibility criteria for IV tPA, based on the PROACT 1, PROACT 2, and MELT trials, with a Grade 2C recommendation 1, 3
IV tPA is preferred over intraarterial tPA when patients meet eligibility criteria for both, as the evidence quality is higher for IV administration, with a Grade 2C recommendation 1, 3

Within any chosen time window, treat as rapidly as possible, as earlier treatment provides substantially greater benefit, with an odds ratio of 2.11 for excellent recovery when treated within 90 minutes, compared to 1.69 for treatment at 90-180 minutes 2, 4
Do not administer antiplatelet or anticoagulant therapy for 24 hours after tPA, and initiate aspirin 160-325 mg within 48 hours of stroke onset, with a Grade 1A recommendation 1, 3, 4

Do not exclude patients with minor strokes from consideration for tPA within the appropriate time windows, as they may still benefit 4, 5
Do not treat if blood pressure cannot be controlled below 185/110 mmHg before initiating tPA, as this is an absolute contraindication, and monitor blood pressure every 15 minutes during infusion and for 2 hours after, then every 30 minutes for 6 hours, maintaining BP <180/105 mmHg 4