In-hospital clinical outcomes in diffusion weighted imaging-negative stroke treated with intravenous thrombolysis

Objective We aimed to investigate whether negative diffusion weighted imaging (DWI) is related to the in-hospital clinical outcomes for ischemic stroke patients with intravenous tissues plasminogen activator (IV tPA). Methods We retrospectively enrolled patients who received IV tPA therapy within 4.5 hours from symptoms onset. The classification of DWI-positive or negative was based on post-IV tPA MR scan. Demographic factors, stroke characteristics, imaging information, and the in-hospital clinical outcomes including early neurological improvement (ENI) and favourable functional outcome were collected. Multivariable logistic regression and sensitivity analyses were conducted to test whether negative DWI imaging was an independent predictor of the in-hospital clinical outcomes. Results In the final study population, 437 patients treated with IV tPA were included and 12.36% of them had negative DWI imaging at the first MR scan post IV tPA. In the DWI-negative group, 51.9% (28/54) of the patients achieved ENI at 24 hours and 74.1% (40/54) of the patients achieved favourable clinical outcome at discharge. DWI-negative was not related to ENI (adjusted odds ratio 0.93, 95% confidence interval 0.17-4.91) or favourable clinical outcome (adjusted odds ratio 2.40, 95% confidence interval 0.48-11.95). Additional sensitivity analyses yielded similar results. Conclusion DWI-negative is not associated with ENI or favourable functional outcome at discharge. Keywords: Stroke, Thrombolysis, Tissue plasminogen activator, Diffusion magnetic resonance imaging