Which statement best describes the main eligibility criteria for IV alteplase in suspected AIS?

Which statement best describes the main eligibility criteria for IV alteplase in suspected AIS?

• A. Onset within 6 hours, any CT finding
• B. Onset within 4.5 hours, no hemorrhage on CT, and no major contraindications
• C. Onset within 4.5 hours and perfusion imaging mandatory
• D. Eligibility depends only on age

Answer: (B)

IV alteplase is given only when the stroke is suspected to be ischemic and the benefits of dissolving the clot outweigh the bleeding risk, which depends on time, imaging, and safety factors. The statement that best fits this balance says you must treat within four and a half hours of onset, there is no intracranial hemorrhage on the CT, and there are no major contraindications. The four-and-a-half-hour window is supported by evidence showing better outcomes with earlier treatment; a six-hour window is not standard practice for initial IV tPA. A CT without hemorrhage is essential because tPA increases bleeding risk, so confirming there’s no bleed is a critical safety check. “No major contraindications” covers other high-risk situations (like uncontrolled hypertension, recent major surgery or bleeding risk, or severe coagulopathy) that would make tPA inappropriate. The other options misstate the time window, impose unnecessary imaging requirements, or rely on age alone, which does not capture the full safety and timing criteria used in practice.

IV alteplase is given only when the stroke is suspected to be ischemic and the benefits of dissolving the clot outweigh the bleeding risk, which depends on time, imaging, and safety factors. The statement that best fits this balance says you must treat within four and a half hours of onset, there is no intracranial hemorrhage on the CT, and there are no major contraindications. The four-and-a-half-hour window is supported by evidence showing better outcomes with earlier treatment; a six-hour window is not standard practice for initial IV tPA. A CT without hemorrhage is essential because tPA increases bleeding risk, so confirming there’s no bleed is a critical safety check. “No major contraindications” covers other high-risk situations (like uncontrolled hypertension, recent major surgery or bleeding risk, or severe coagulopathy) that would make tPA inappropriate. The other options misstate the time window, impose unnecessary imaging requirements, or rely on age alone, which does not capture the full safety and timing criteria used in practice.