Abstract TP64: Optimal Minor Stroke Definition For Thrombolysis Decision-making
Background and purpose: Patients with a low National Institutes of Health Stroke Scale (NIHSS) score are frequently excluded from thrombolysis, but >25% of those patients remain disabled. We sought to define a minor stroke definition that helps guide treatment decision-making.
Methods: From a stroke outcome database, untreated patients with NIHSS ≤5 presenting within a 4.5-hour window were identified. The validity of the following minor stroke definitions were assessed: 1) the National Institute of Neurological Disorders and Stroke Tissue Plasminogen Activator (NINDS-TPA) trials’ definition; 2) the total NIHSS score, varying a threshold from 0 to 4; 3) our proposed definition which included NIHSS=0 or NIHSS=1 in the items of level of consciousness, gaze, facial palsy, sensory, or dysarthria.
Results: Of 647 included patients, 172 (26.6%) had a 3-month unfavorable outcome (modified Rankin Scale 2-6). When the NINDS-TPA trials’ definition, our proposed definition, or NIHSS ≤1 definition was applied, >75% of patients with an unfavorable outcome were defined as a non-minor stroke and >85% of those defined as a minor stroke had a favorable outcome. For a hypothetical population of 1000 patients with NIHSS ≤5, as compared to the NINDS-TPA trials’ definition, our definition would treat additional 23 patients and increase 17-18 favorable outcomes at the expense of 1-2 symptomatic hemorrhagic transformations (SHTs), whereas the NIHSS ≤1 definition would further exclude 54 patients from treatment and the benefit of avoiding 1-4 SHTs would be negated by the increase of three unfavorable outcomes among untreated patients.
Conclusion: A validated criterion should be applied to thrombolysis decision-making for patients with a mild deficit. Our definition would further increase the treatment rate and favorable outcomes.
- © 2012 by American Heart Association, Inc.