Background: In the ESCAPE trial, patients with large vessel occlusions and small infarct cores identified with CT/CT angiography were randomized to endovascular therapy or standard of care. CT Perfusion (CTP) was obtained in some cases, but was not utilized to select patients. We tested the hypothesis that patients with penumbral CTP patterns have higher rates of good clinical outcome.
Methods: All CTP data acquired in ESCAPE patients was analyzed centrally using a semi-automated perfusion threshold based approach. A penumbral pattern was defined as an infarct core<70 mL, penumbral volume >15 mL, and a total hypoperfused volume:core volume ratio of >1.8. The primary outcome was a good functional outcome at 90 days (mRS 0-2).
Results: CTP was acquired in 138 of 316 ESCAPE patients. Motion degraded CTP images from 9 patients were excluded. Penumbral patterns were present in 110/129 (85.3%) of patients. The rate of good functional outcome in penumbral pattern patients (53/108; 49.1%) was higher than that in non-penumbral patients (3/19; 15.8%, p=0.011). In penumbral patients, endovascular therapy increased the likelihood of good outcome (35/58; 60.3%) over those in the control group (18/50; 36%, OR=2.71, p=0.013). Only 4 of 19 non-penumbral patients were randomized to the endovascular group, preventing an analysis of treatment effect.
Conclusion: The majority of patients with CTP imaging in the ESCAPE trial had penumbral patterns, which were associated with better outcomes overall. Patients with penumbra treated with endovascular therapy had the greatest odds of good functional outcome. Non-penumbral patients were much less likely to achieve good outcomes.