The effect of apolipoprotein E genotype on neuron specific enolase and S-100β levels after cardiac surgery

We tested the hypothesis that two biochemical markers of brain injury would be increased after cardiac surgery in patients with the apolipoprotein (Apo) ε4 allele. Arterial blood samples were drawn before and 8 and 24 h after induction of anesthesia and later assayed for neuron specific enolase (NSE), S-100β, and apoE genotype. There was a highly significant temporal effect with increases in NSE (2.2 ± 1.6 ng/L to 11.8 ± 8.9 ng/L; P < 0.0001) (mean ± SD) and S-100β (0.15 ± 0.1 μg/L to 0.45 ± 0.42 μg/L, P < 0.0001). At 8 and 24 h after induction of anesthesia S-100β (0.28 ± 0.18 μg/L versus 0.91 ± 0.54 μg/L; P = 0.004) and NSE (8.6 ± 5.6 ng/L versus 19.0 ± 19.7 ng/L; P = 0.02) levels, respectively, were higher in patients with the Apoε4 allele. Patients with the Apoε4 allele may be more susceptible to perioperative neural insults.