Abstract 46: Outcomes of Thrombolysis for In-hospital Stroke: A Population-Based Study of US Hospitals

Abstract

Background: In-hospital stroke (IHS) may differ from out-of-hospital stroke (OHS) in terms of mechanism, risk factors and outcomes. Objective/Hypothesis: We compared IHS and OHS treated with systemic or intra-arterial thrombolysis from a large national cohort in a cross-sectional study to further clarify these differences. Our hypothesis was that there would be poorer patient outcomes associated with IHS than OHS. Methods: Nationwide inpatient sample (NIS) for years 2005-2009 was searched for stroke cases treated with thrombolysis by using International Classification of Diseases-9 codes. Patients treated on the day of admission were classified as OHS. Primary outcome measures were inpatient mortality and functional independence at discharge as indicated by discharge to home (self-care). Secondary outcomes included intracranial hemorrhage (ICH), GI bleeding, tracheostomy and gastrostomy tube placement. IHS as an independent predictor of outcomes was studied using multivariate logistic regression. Results: IHS comprised of 1,054 (11.3%) cases of all (N=9,353) thrombolysed ischemic strokes. IHS was associated with higher co-morbidity profile and higher rates of acute medical conditions. In unadjusted analyses, IHS had higher inpatient mortality (18.8% vs. 10.9%, p<0.001) and lower rate of functional independence at discharge (21.7 vs. 28.6%, p<0.001). While IHS had higher rates of GI bleeding, tracheostomy and gastrostomy, the rate of ICH in IHS was similar to that of OHS (4.6% vs. 4.8%, p=0.807). After controlling for demographics, hospital characteristics and co-morbidities, inpatient mortality (adj. OR:1.82; 95% CI:1.53-2.16, p<0.001) and favorable discharge outcome (adj. OR:0.80; 95% CI:0.68-0.94, p=0.007)) remained significantly worse in IHS while the rate of ICH (adj. OR:0.91; 95% CI:0.67-1.23) remained similar to that of OHS. Conclusions: Thrombolysis in IHS is associated with worse outcomes and higher rates of inpatient medical complications compared to OHS, likely due to their higher co-morbidities and additional medical reasons for hospital admission. In spite of presumed higher bleeding risk in IHS, thrombolytic use is not associated with higher rate of ICH among IHS.