Effect of APOE Gene Polymorphism on Early Cerebral Perfusion After Aneurysmal Subarachnoid Hemorrhage

High mortality following aneurysmal subarachnoid hemorrhage (aSAH) occurs in the early phase, but the underlying mechanism of early brain injury (EBI) in aSAH was less elucidated. In this study, we aimed to investigate the association of apolipoprotein E (APOE) genotypes and early cerebral perfusion after aSAH. We collected venous blood of aSAH patients on admission for APOE genotype identification, applying computed tomography perfusion (CTP) scanning within 24 h after onset. The CTP parameters between patients with different APOE genotypes were compared. Then, a positive item was chosen for separate uni- and multivariate logistic regression analyses to seek its risk factors. Our results showed mean transit time (MTT) rather than other parameters was significantly longer in patients with the APOE epsilon 4 allele, compared to those without APOE epsilon 4 (6.45 +/- 1.17 versus 5.83 +/- 0.84 s, P = 0.019). APOE epsilon 4 acted as an independent risk factor for MTT prolongation (> 5.9 s) in uni- (P = 0.031, OR = 3.960, 95 % CI = 1.131-13.863) and multivariate (P = 0.019, OR = 9.822, 95 % CI = 1.458-66.193) logistic regression analyses, respectively. APOE epsilon 4 may induce cerebral perfusion impairment in the early phase, contributing to EBI following aSAH, and assessment of APOE genotypes could serve as a useful tool in the prognostic evaluation and therapeutic management of aSAH.