Apolipoprotein E4 genotype increases the risk of postoperative cognitive dysfunction in patients undergoing coronary artery bypass graft surgery.

AIM: The aim of this study was to investigate the association between the presence of ApoE4 and the incidence of postoperative cognitive dysfunction (POCD) after cardiac surgery.

METHODS

Eighty-seven adult patients undergoing elective coronary artery bypass graft surgery were observed prospectively at a university tertiary care hospital. All patients were evaluated with the Mini-Mental State Examination (MMSE) and the Glasgow Coma Scale (GCS) for cognitive function and mental status preoperatively, 24 h after surgery and at postoperative day 6. Patients were genotyped for the ApoE polymorphism. The association between ApoE genotype and MMSE evolution was studied by using repeated measures ANOVA.

RESULTS

Both the presence of at least one ApoE4 allele and POCD were verified in 21.8% of subjects. The presence of the ApoE4 allele was significantly associated with a worse MMSE score evolution (P=0.04).

CONCLUSION

This study suggests an association between ApoE4 and early POCD, but further studies are needed to clarify a causative association. Such new studies should include a more homogenous patient sample and a longer follow-up.