Background: Intravenous thrombolysis improves outcomes of stroke patients. The immediate response to thrombolysis is variable and few studies attempted to identify predictors of major neurological improvement (MNI) 24 h following thrombolysis. Our objective is to determine predictors of MNI 24 h following thrombolysis.
Methods: We reviewed the prospective database of patients treated through our telestroke network and at our institution between November 2008 and June 2012. We included all patients who received IV t-PA and had a 24-h NIHSS score available. Similar to previous studies, we defined MNI as a reduction in NIHSS score by ≥8 points, or a score of 0 or 1 at 24 h. Demographics, risk factors, time to treatment, and clinical and laboratory data, were compared between MNI present or absent. Baseline predictors were compared using t- and Fisher's exact tests, and outcomes using multivariate logistic regression analysis.
Results: Out of 316 patients, 306 had 24-h NIHSS scores and 38% of them experienced MNI. Patients with MNI were less likely to be older than 80 years (16% vs. 29%, p = 0.008) and to have atrial fibrillation (9% vs. 24%, p = 0.001) compared to those without; we found no other predictors of MNI. After adjusting for baseline demographics and risk factors, age less than 80 years (OR = 1.9, 95% CI 1.1-3.6) and absence of atrial fibrillation (OR = 3.0, 95% CI: 1.4-6.2) predicted MNI.
Conclusion: Major neurological improvement within 24 h after thrombolysis is more likely in younger patients and those without atrial fibrillation.
Keywords: atrial fibrillation; ischemic stroke; major neurological improvement; outcome; thrombolysis.