Abstract 3520: Major Neurological Improvement is Predicted by Recanalisation and Absence of Acute Tissue Damage: An Analysis of 2'006 Consecutive Acute Ischemic Strokes

Abstract

Introduction: Major neurological improvement (MNI) in acute ischemic stroke (AIS) is related to better outcome. We aimed to evaluate predictors of MNI in a large cohort of consecutive AIS patients. Methods: In the Acute STroke Registry and Analysis of Lausanne (ASTRAL), MNI was defined as ≥ 8 point improvement of NIHSS or a NIHSS of 0-1 after 24 hours. Patients with initial NIHSS of 0-1 were excluded and missing data were imputed. For comparison of patients with and without MNI, logistic regression analysis of a large number of demographical, clinical, radiological and metabolic data was performed. The influence of MNI on length of hospital stay (LOS), favorable outcome defined as modified Rankin score 0-2 at three and 12 months, and recurrence was also assessed in univariate analysis. Results: 203 patients were excluded because of initial NIHSS of 0-1. Before imputing 50 missing NIHSS values to obtain a sample of 2’006 patients, MNI occurred in 333 (17.0%). MNI was predicted by spontaneous or therapeutic intracranial recanalization (OR= 0.49, CI 0.31-0.76, p<0.01) especially in the presence of eye deviation, absence of early ischemic lesions on neuroimaging (OR= 0.62, CI 0.47-0.82, p<0.01), earlier onset to arrival delay (OR= 0.95/60 minutes, CI 0.93 - 0.97, p<0.01) and lower systolic blood pressure at 24h (OR=0.92/10 mmHg, CI 0.86 - 0.98, p=0.01). Patients with MNI had significantly shorter LOS (median 8 vs. 10 days, p<0.01), more frequent favorable three months (73.6% vs. 47.6%, p<0.01) and 12 months outcome (66.1 vs. 43.5, p < 0.01). They also had less three (3.9% vs. 17.3%, p<0.01) and 12 months fatality (6.0% vs. 21.8% p < 0.01). Recurrence rates at three months were similar (9.0% vs. 9.2%, p=0.86). Conclusion: Absence of radiological signs of irreversible tissue damage and arterial recanalisation are strong predictors of MNI. Earlier arrival to hospital delay and lower subacute SBP also contributed to MNI. We confirm that radiological markers are strong predictors of MNI in thrombolysed and untreated patients.