Abstract WP85: Clinical and Imaging Predictors, and Functional Outcomes, of Fast, Intermediate, and Slow Progression Among Patients With Large Vessel Occlusion Acute Ischemic Stroke

Abstract

Background: Speed of infarct progression varies widely in acute ischemic stroke and is a major determinant of outcome. Patient demographic, clinical, and imaging features associated with slow, intermediate, and rapid infarct growth have not been well delineated. Methods: In a prospectively maintained stroke center registry, we analyzed consecutive patients with anterior circulation large vessel occlusion who underwent first multimodal MRI or CT imaging within 24 hours of onset. The speed of initial infarct progression was calculated as ischemic core volume at first imaging divided by the time from stroke onset to imaging. Results: Among the 88 patients, age was mean 71.6 ± 15.0; 51% were women; initial NIHSS was 16.1 ± 6.5), and time from onset to first imaging was median 3.3h (full range 0.6 - 23.0). The speed of infarct progression was median 2.2 cc/hr (interquartile range 0 - 8.7), ranging most widely among patients imaged within the first 6 hours after onset. Faster speed of infarct progression was positively independently associated with low collateral score (OR 3.30, 95%CI 1.25 - 10.49) and arrival by emergency medical services rather than transfer (OR 3.34, 95% CI 1.06 - 10.49) and negatively independently associated with prior ischemic stroke (OR 0.12, 95%CI 0.03 - 0.50) and coronary artery disease (OR 0.32, 95%CI 0.10 - 1.00). Among the 67 patients who underwent endovascular thrombectomy, slower speeds of infarct progression were associated with shift to reduced levels of disability at discharge (OR 3.26, 95% CI 1.02 - 10.45). In addition, slower speed of infarct progression was associated with favorable shift to recanalization by thrombectomy (OR 8.30, 95%CI 0.97 - 70-.87) and reduced radiologic hemorrhagic transformation (OR 0.34, 95% CI 0.12 - 0.94). Conclusion: Slower speed of initial infarct progression is associated with high collateral score, prior ischemic stroke, and coronary artery disease, supporting roles for both collateral robustness and ischemic precondition in fostering tissue resilience to ischemia. Among patients undergoing endovascular thrombectomy, speed of initial infarct progression is a major determinant of clinical outcome.