Abstract TP47: Prediction of Stroke Outcome With Immediate Post-Thrombolysis Magnetic Resonance Imaging

Abstract

Background: Early recanalization and adequate collateral blood flow are strong surrogates for functional recovery in endovascular stroke treatment. We sought to evaluate the prognostic value of immediate post-thrombolysis magnetic resonance imaging (MRI). Methods: Consecutive patients with acute ischemic stroke who underwent endovascular treatment were enrolled. We measured diffusion-weighted MRI (DWI) and perfusion-weighted MRI (PWI) lesion volume, mismatch ratio, and DWI and PWI lesion volume change before and immediate after treatment. Outcome was measured with modified Rankin Scale (mRS) at 90 days, early neurological improvement (NIHSS ≥ 8) within 7 days, and any intracerebral hemorrhage. Multivariate analysis and c -statistics were used to identify prognostic value of MR parameters. Results: A total of 65 patients with a complete pre- and post-thrombolysis MRI were included. Mean age was 65±18 years, median baseline NIHSS score was 14, and median time from symptom onset to endovascular treatment was 192 minutes. Median time from endovascular treatment to post-treatment MRI was 20 minutes. After control of initial stroke severity and complete recanalization on angiography, post-thrombolysis PWI lesion volume remained an independent predictor of favorable outcome ( p = 0.017, odds ratio [OR] = 0.970, 95% confidence interval [CI] = 0.946-0.995), and early neurological improvement ( p = 0.014, OR = 0.957, 95% CI = 0.923-0.991), whereas DWI lesion volume, mismatch ratio, and DWI and PWI lesion volume changes did not show statistical significance. None of the measured variables predicts intracerebral hemorrhage. Post-thrombolysis PWI lesion volume revealed area under the curve of 0.821 (p < 0.001, 95% CI = 0.722-0.920) for favorable outcome and 0.878 (p < 0.001, 95% CI = 0.799-0.957) for early neurological improvement. Conclusions: Perfusion lesion volume on immediate post-thrombolysis MRI more accurately predicts functional recovery and early neurological improvement than pre-treatment DWI and PWI parameters.