Temporal Trends in Clinical Characteristics and Door-to-Needle Time in Patients Receiving Intravenous Tissue Plasminogen Activator: A Retrospective Study of 4 Hospitals in Japan

Abstract Background: Intravenous recombinant tissue plasminogen activator (rt-PA) has become a common treatment for acute ischemic stroke and has highly time-dependent benefits. We aimed to clarify temporal trends regarding the frequency and characteristics of patients receiving rt-PA and explore factors associated with door-to-needle time (DNT) in Japanese emergency hospitals. Methods: Consecutive patients who received intravenous rt-PA for acute ischemic stroke from October 2005 to December 2015 were retrospectively registered from 4 hospitals. Temporal trends in the frequency and characteristics of patients receiving rt-PA and factors associated with DNT were investigated. Results: A total of 750 patients, including 688 (420 men, median 75 years old) with out-of-hospital stroke, were registered. The frequency of patients receiving intravenous rt-PA for acute ischemic stroke continuously increased from 1.8% in 2005 to 9.5% in 2015. The proportion of patients who were elderly or had prestroke disability increased over time, while pretreatment stroke severity declined. The DNT gradually decreased (median 105 minutes in 2005, 61 minutes in 2015). According to multivariate regression analysis with correction for multiple comparisons, activation of a code stroke system (standardized partial regression coefficient (β) −.50, P