APOE ε2 is associated with reduced risk of early post-stroke cognitive impairment but not with long-term functional outcome.

BACKGROUND: The associations between APOE genotype and early cognitive impairment and long-term functional prognosis after acute ischemic stroke (AIS) are uncertain. OBJECTIVE: To investigate the associations between APOE genotype and early cognitive impairment and long-term functional prognosis after AIS. METHODS: Our study was a single-center, prospective cohort study, that included 109 patients with AIS. At baseline, APOE genotype, cognition and white matter hyperintensities (WMH) were assessed within 2 weeks of stroke onset. At 3 months and 18 months, the modified Rankin scale (mRS) was used to assess the functional outcome after stroke. RESULTS: ε2 carriers had better cognitive performance than ε2 noncarriers did in the Montreal Cognitive Assessment (MoCA, p = 0.003) and the Trail Making Test (TMT, p = 0.038). Multivariate logistic regression analysis revealed that ε2 was an independent protective factor for early post-stroke cognitive impairment (OR 0.213, 95% CI 0.055–0.820), whereas ε4 was not associated with early post-stroke cognitive impairment (OR 2.582, 95% CI 0.314–21.219). ε2 had no significant effect on WMH, whereas ε4 aggravated WMH, especially in the deep white matter (DWM). No significant interaction effect between the Fazekas score and ε2 on early post-stroke cognitive impairment was found. Female sex (OR 7.081, 95% CI 2.531–19.813), admission NIHSS score (OR 1.265, 95% CI 1.062–1.507), and DWM Fazekas score (OR 2.224, 95% CI 1.106–4.469) were independent risk factors for long-term unfavorable prognosis after ischemic stroke. CONCLUSION: ε2 was associated with reduced risk of early post-stroke cognitive impairment, but not with the favorable long-term functional prognosis after stroke.