What is the time window for intravenous tPA in acute ischemic stroke?

What is the time window for intravenous tPA in acute ischemic stroke?

• A. Within 3 hours
• B. Within 6 hours
• C. Within 24 hours
• D. Within 4.5 hours

Answer: (D)

The key idea here is that intravenous tPA is time-sensitive in acute ischemic stroke, and the eligible window has been broadened based on clinical trial data. Intravenous alteplase should be started as soon as possible after stroke onset. Historically the main window was 3 hours, but evidence from the ECASS-3 trial showed that selected patients could still benefit if treatment began within 4.5 hours. As a result, current guidelines permit IV tPA up to 4.5 hours after onset for eligible patients, provided there are no contraindications. Beyond 4.5 hours, IV tPA is not recommended because the risks (notably hemorrhagic transformation) outweigh potential benefits. So the time frame that best fits modern practice for IV tPA in acute ischemic stroke is within 4.5 hours.

The key idea here is that intravenous tPA is time-sensitive in acute ischemic stroke, and the eligible window has been broadened based on clinical trial data. Intravenous alteplase should be started as soon as possible after stroke onset. Historically the main window was 3 hours, but evidence from the ECASS-3 trial showed that selected patients could still benefit if treatment began within 4.5 hours. As a result, current guidelines permit IV tPA up to 4.5 hours after onset for eligible patients, provided there are no contraindications.

Beyond 4.5 hours, IV tPA is not recommended because the risks (notably hemorrhagic transformation) outweigh potential benefits. So the time frame that best fits modern practice for IV tPA in acute ischemic stroke is within 4.5 hours.