After followed for 2 years, a prospective cohort study found that the interaction between permanent non-valvular AF and APOE ɛ4 genotype was linked with a higher risk of cognitive impairment [43], which suggested that APOE ɛ4 genotype may participate in the occurrence of AF through some mechanism in Alzheimer’s disease. The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.