Factors associated with in-hospital mortality after administration of thrombolysis in acute ischemic stroke patients: an analysis of the nationwide inpatient sample 1999 to 2002

Abstract

Background and purpose: The prospective trials evaluating the safety and efficacy of intravenous tissue plasminogen activator have generally been conducted at academic medical centers and community hospitals with an institutional commitment to stroke care. Relatively little is known about the safety of this therapy as it is used in the community. We therefore examined outcomes in acute stroke patients treated with thrombolysis using the largest discharge database available in the United States for the years 1999 to 2002.

Methods: Data were derived from the Nationwide Inpatient Sample for the years 1999 to 2002. Using the appropriate International Classification of Disease-Clinical Modification, 9th revision, codes, patients admitted through the emergency room with a primary diagnosis of acute ischemic stroke were selected for analysis. From these patients, those coded as receiving thrombolysis were identified. Multivariate logistic regression was performed on the thrombolysis and nonthrombolysis cohorts to identify independent predictors of in-hospital mortality from among those clinical elements available in the database.

Results: We identified 2594 patients treated with thrombolysis from a group of 248,964 patients admitted through the emergency room with a primary diagnosis of acute ischemic stroke. The thrombolysis cohort had a higher in-hospital mortality rate compared with the nonthrombolysis patients (11.4% versus 6.8%). The rate of intracerebral hemorrhage was 4.4% for the thrombolysis cohort and 0.4% for nonthrombolysis patients. Multivariate logistic regression showed advanced age, Asian/Pacific Islander race, congestive heart failure, and atrial fibrillation/flutter to be independent predictors of in-hospital mortality after thrombolysis. Thrombolysis volume, overall ischemic stroke volume, and teaching status were not significant predictors of in-hospital mortality after thrombolysis.

Conclusions: Thrombolysis, as it is used in the community, has a safety profile that is similar to that observed in the large, prospective clinical trials.