Abstract W MP12: Sequential NIHSS Change is a Better Predictor of Good Functional Outcome than Pre-Treatment Neurological Status after Mechanical Thrombectomy in Acute Stroke

Abstract

Purpose: Pre-treatment NIHSS has been shown to be the strongest predictor of outcome after endovascular therapy in acute ischemic stroke. However, it is not clear if sequential changes in NIHSS scores have any predictive value after mechanical thrombectomy cases. Methods: Prospective (Pivotal N=119, PICS N=219, START N=124) and retrospective/registry (POST N=95, RetroSTART N=168) cases using the Penumbra System were pooled. All were IV tPA-ineligible or refractory with treatment at <8 h. The association of NIHSS pre- and post-treatment and good clinical outcome (mRS 0-2 at 90 days) was tested. Results: Among 725 patients, mean age was 66 ± 15 and median admission NIHSS score was 17 (IQR 13-21). Median NIHSS improved to 11 at 7 days. NIHSS scores at 7 days showed a stronger relationship with good outcome (correlation 0.84; p<0.001) than baseline (correlation 0.37; p<0.001). Furthermore, serial NIHSS scores (baseline minus 7 day) also predicted good outcome (correlation -0.69; p<0.001). Age (correlation 0.39, p < 0.001), pre-treatment ASPECTS score (correlation -0.19; p < 0.001) but not reperfusion to TIMI 2-3/TICI 2b-3 also demonstrated associations with good outcome. Conclusion: In this pooled Penumbra cohort, post treatment improvement in neurological status significantly predicted good clinical and functional outcomes, independent of reperfusion status.