Thrombolysis Administration After Minor Ischemic Stroke Not Associated with Subsequent Dementia Incidence
International Journal of Stroke
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Background: Thrombolysis (tPA) administered within 4.5 hours of ischemic stroke is the current standard of care for hyperacute stroke management. Utilization of tPA increased after the implementation of integrated stroke care in Ontario, Canada. We have recently shown that tPA administered within 4.5 hours of stroke onset is associated with reduced risk of dementia incidence. Given the wide spectrum of stroke severities, we investigated whether this clinical benefit persisted among those diagnosed with minor stroke.
Methods: We included all minor ischemic stroke patients (NIHSS< = 5) from July 1, 2003 to March 31, 2013 in the Ontario Stroke Registry (OSR) who were free of dementia at stroke onset. Patients were followed after stroke for dementia incidence at 1 year and 4 years. Dementia diagnosis was obtained using a validated algorithm from administrative databases. Cox regression, with death adjusted as competing risk and hospitals as random effects, modelled thrombolysis administration following stroke and dementia incidence, while adjusting for demographic and clinical characteristics. Data was analyzed at the Institute for Clinical Evaluative Sciences. Results: A total of 9,633 stroke patients were included in the analysis. Thrombolysis reduced the risk of dementia incidence by 12% at 1 year post-stroke [cause-specific HR = 0.88 (95% CI:0.57–1.36) and by 2% at 4 years post-stroke [cause-specific HR = 0.98 (95% CI:0.66–1.47).
Conclusions: Among patients with NIHSS< = 5, administration of thrombolytic therapy was not associated with reduced risk of dementia incidence 1 year and 4 years following minor stroke onset.