Treatment of Acute Ischemic Stroke: A Review

Importance Acute ischemic stroke, caused by thrombotic or embolic occlusion of a cervical or cerebral artery, leads to neurologic injury due to sudden disruption of blood flow to the brain. Ischemic stroke is a leading cause of disability and death and accounts for about 85% of strokes in the US. Observations Symptoms of acute ischemic stroke vary based on the area of the affected brain. Common presentations include sudden arm or leg weakness, aphasia or slurred speech, sudden loss of balance or coordination, sudden visual difficulties, and/or facial drooping. Patients with suspected stroke should be transported to the nearest emergency department for urgent brain imaging, typically noncontrast computed tomography (CT). Based on 2026 American Heart Association/American Stroke Association (AHA/ASA) guidelines, first-line therapy for patients with acute ischemic stroke presenting within 4.5 hours from symptom onset with disabling symptoms (eg, affecting the ability to perform activities of daily living) is intravenous thrombolysis (tenecteplase or alteplase) in those without intracranial hemorrhage or other contraindications to thrombolysis. The treatment window can be extended to 9 hours—and up to 24 hours in patients with large vessel occlusion (eg, involving the internal carotid artery or proximal middle cerebral artery [M1 segment]) who are unable to receive thrombectomy—based on identification of salvageable tissue using perfusion imaging with CT perfusion or magnetic resonance imaging. In appropriately selected patients with acute ischemic stroke, pooled randomized trial data show an approximately 10% absolute increase in the probability of a better functional outcome with intravenous thrombolysis. Based on 2026 AHA/ASA guidelines, endovascular thrombectomy, which involves clot removal with an intra-arterial mechanical device, is recommended for patients with large vessel occlusion within 6 hours of stroke onset (class 1 recommendation) and is recommended in selected patients with large vessel occlusion within 24 hours of last known well (class 1 recommendation). Endovascular therapy should be performed after intravenous thrombolysis unless patients have contraindications to thrombolytic therapy. Compared with medical management, which includes intravenous thrombolysis when indicated, endovascular thrombectomy produces an approximately 20% absolute increase in functional independence. Conclusions and Relevance Acute ischemic stroke causes substantial disability and mortality. First-line therapy for patients with disabling acute stroke symptoms is intravenous thrombolysis (if no contraindications) within 4.5 hours of stroke onset and up to 24 hours in carefully selected patients not receiving mechanical thrombectomy; for large vessel occlusions, mechanical thrombectomy may be performed up to 24 hours after stroke onset in eligible patients.