Long-term survival of ischemic stroke patients according to prior cognitive status. Dijon Stroke Registry.

INTRODUCTION: Understanding the influence of preexisting cognitive impairment on poststroke outcome is a critical challenge in a context of current aging and growing population. This study aimed to assess long-term survival of patients with acute ischemic stroke (IS) according to their premorbid cognitive status, and to identify contributing factors of death.

METHODS: Patients with IS were prospectively identified among residents of Dijon, France using a population-based registry (2013-2017). The association between case-fatality at 5 years and prestroke cognitive status was assessed by multivariable Cox models adjusted for other clinical characteristics and preexisting brain damage on initial CT-scan including leukoaraiosis, old vascular brain lesions, and cortical and central brain atrophy, as well as major arterial occlusion.

RESULTS: 1049 patients were included (mean age ±SD: 76.3 ±15.2 years old, 54% women). Case-fatality rates at 5 years were 38.1% in patients without cognitive impairment, 65.9% in patients with prior mild cognitive impairment (MCI, n=132, 12.6%), and 86.6% in patients with dementia (n=164, 15.6%) (p<0.001). MCI (HR=1.39; 95% CI: 1.06-1.81, p=0.016), and dementia (HR=1.89; 95% CI: 1.45-2.46, p<0.001 for dementia) were both independently associated with higher case-fatality after adjustment for clinical variables. The association remained significant after further adjustment for preexisting brain damage and major arterial occlusion (HR=1.47; 95% CI: 1.10-1.98, p=0.009 for MCI and HR=1.90; 95% CI: 1.43-2.53, p<0.001 for dementia) among patients with available data on CT-scan (n=916). Factors associated with death were roughly similar across groups.

CONCLUSION: This study highlighted a poor long-term survival of IS patients with preexisting cognitive impairment, independently of other contributing factors of death. It is critical to better understand the trajectory of IS patients with preexisting cognitive impairment, and to identify prognostic markers to guide clinicians in their management strategies.