Patients with premorbid dementia have been generally excluded from trials of stroke therapies, and their dementia diagnosis may affect the care received. There are few data on the quality of stroke care and outcomes in these patients.

We compared the quality of care and outcomes for acute ischemic stroke patients with versus without premorbid dementia using national data from the Get With The Guidelines-Stroke registry between July 1, 2020, and December 31, 2021. Process outcomes included receiving intravenous thrombolysis, endovascular thrombectomy, and additional national quality measures. Clinical outcomes included ambulatory status at discharge, discharge destination, and mortality. The analyses were adjusted for patient and hospital characteristics.

Among 609 350 patients with acute ischemic stroke, 29 751 of 546 407 (5.4%) had documented prestroke dementia (median age, 84 [interquartile range, 78-89]; 62.8% female). Patients with versus without premorbid dementia were more likely to arrive via emergency medical services (70.5% versus 46.8%) and had more severe strokes (median National Institutes of Health Stroke Scale score, 7 [interquartile range, 3-15] versus 3 [interquartile range, 1-8]). They were less likely to be admitted to a comprehensive stroke center (17.9% versus 22.7%; <0.0001), to receive intravenous thrombolysis (9.6% versus 11.1%; adjusted odds ratio [aOR], 0.91 [95% CI, 0.87-0.95]) or endovascular thrombectomy (4.5% versus 7.4%; aOR, 0.62 [95% CI, 0.56-0.68]), attain each of the Get With The Guidelines-Stroke Achievement Measures and Quality Measures, or attain defect-free stroke care (92.0% versus 95.0%; aOR, 0.75 [95% CI, 0.71-0.78]). Patients with premorbid dementia had longer door-to-needle times (adjusted difference, 3.17 minutes [95% CI, 1.34-5.01]), lower odds of being discharged home (43.8% versus 60.1%; aOR, 0.96 [95% CI, 0.93-1.00]), and higher odds of being nonambulatory at discharge (25.8% versus 9.3%; aOR, 1.62 [95% CI, 1.54-1.69]), and of in-hospital mortality or hospice admission (23.3% versus 8.6%; aOR, 1.38 [95% CI, 1.32-1.43]). Symptomatic intracranial hemorrhage after intravenous thrombolysis/endovascular thrombectomy did not differ (5.3% versus 3.7%; aOR, 1.13 [95% CI, 0.97-1.31]).

Patients with premorbid dementia experienced slightly poorer quality of stroke care across multiple measures, were less likely to receive acute stroke interventions, and had worse poststroke outcomes than patients without dementia in a large nationwide registry. Our findings underscore the need for concerted efforts to further improve care quality and outcomes in this population.