Perfusion computed tomography to assist decision making for stroke thrombolysis

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Thrombolysis selection for acute ischemic stroke using perfusion imaging lacks phase III trial evidence.
• Perfusion imaging's role in guiding thrombolysis remains debated.
• Recombinant tissue plasminogen activator (rtPA) is a key treatment for acute ischemic stroke.

Purpose of the Study:

• To evaluate outcomes of rtPA-treated stroke patients selected using perfusion computed tomography (CT).
• To test the hypothesis that target mismatch on perfusion CT predicts better rtPA response.
• To compare outcomes of perfusion CT-selected rtPA patients with historical controls.

Main Methods:

• Prospective cohort study of ischemic stroke patients eligible for rtPA.
• Perfusion CT used qualitatively in real-time for treatment decisions.
• Off-line quantitative perfusion CT analysis for 'target' mismatch (mismatch ratio >1.8, core <70 ml, lesion volume >15 ml).
• Primary analysis: 3-month modified Rankin Scale (mRS) in treated vs. untreated patients with target mismatch.
• Secondary analysis: Comparison with historical non-contrast CT-selected rtPA cohort.

Main Results:

• Among patients with target mismatch, rtPA treatment significantly improved 3-month mRS outcomes (OR 13.8, P < 0.001).
• Perfusion CT-selected rtPA patients (n=366) had better outcomes than non-contrast CT-selected patients (n=396).
• Improved odds of excellent outcome (mRS 0-1, OR 1.59, P=0.009) and reduced mortality (OR 0.56, P=0.021) in the perfusion CT group.

Conclusions:

• Perfusion CT-guided selection improves identification of stroke patients likely to benefit from rtPA.
• The findings support the use of perfusion CT to optimize rtPA treatment decisions.
• Observational data suggest perfusion CT enhances patient selection for thrombolysis.