The effect of apolipoprotein E genotype on neuron specific enolase and S-100beta 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) epsilon4 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-100beta, 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-100beta (0.15 +/- 0.1 microg/L to 0.45 +/- 0.42 microg/L, P < 0.0001). At 8 and 24 h after induction of anesthesia S-100beta (0.28 +/- 0.18 microg/L versus 0.91 +/- 0.54 microg/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 Apoepsilon4 allele. Patients with the Apoepsilon4 allele may be more susceptible to perioperative neural insults.