Abstract TMP77: Baseline Nihss-adjusted Time Window For Iv Tpa In Acute Stroke

Abstract

Background: Updated metaanalysis have shown that beneficial effect of iv tPA on functional outcome decreases progressively overtime until 4.5 h. However, given the differential pattern of arterial occlusion, stroke severity and speed of ischemic lesion growth among candidates for reperfusion, the time window should be adjusted accordingly. We aim to identify time windows for different categories of stroke severity and occlusion location. Methods: Were included patients treated according to the criteria of the European Summary of Product Characteristics for alteplase treatment < 4.5h in a Universitary Hospital from 2001- 2011. Patients were grouped according to NIHSS severity in minor NIHSS ≤ 8, moderate stroke NIHSS 9-15, severe stroke NIHSS ≥ 16. We sequentially analyzed time-to-treatment to achieve favorable outcome as mRS ≤ 2 at 3 months. Results: 640 patients were included, of whom 123 patients (19.22%) with minor stroke, 205 (32.5%) with moderate stroke and 312 (48.75%) with severe stroke. The rate of favorable outcome was 79.8%, 62.5%, 24.2% respectively. In patients with minor stroke time-to-treatment did not predict outcome (OR 1.005, 95% CI: 0.997- 1.012; p = 0.264). After adjusting for age and occlusion location only age was a independent variable (OR 1.198; 95% CI: 1.054-1.336; p= 0.001). In patients with moderate stroke time-to-treatment ≤ 240 minutes predict favorable outcome (OR 0.041, 95% CI 0.160- 0.962; p= 0.041), although only age and occlusion location, were independent predictors: (OR 1.061, 95% CI 1.024- 1.098; p= 0.001) and (OR 2.968, 95% CI 1.293- 6.614; p= 0.010), respectively. In patients with severe stroke time-to-treatment ≤ 90 minutes predict favorable outcome (OR 0.428, 95% CI 0.186-0.985; p= 0.046). Adjusting for proximal occlusion, age and time-to-treatment before 90 minutes were independent variables: age (OR 1.045, 95% CI 1.014-1.077, p= 0.004) and time-to-treatment (OR 0.267, 95% CI 0.088- 0.809, p= 0.020) Conclusions: The impact of time-to-treatment on favorable outcome varies widely depending on baseline stroke severity. The window for favorable outcome was <90min for severe strokes and extends to <240min in moderate stokes. However, time-to-treatment appeared unrelated to functional outcome in minor stroke.