Apolipoprotein E polymorphisms and age at first coronary artery bypass graft

Apolipoprotein E (apoE) polymorphisms are heritable determinants of total a nd low-density lipoprotein cholesterol. The impact of apoE4 genotypes on th e severity of atherosclerosis has been debated; however, recent studies hav e identified a correlation between apoE4 genotype and atherosclerosis. We a ssessed the impact of apoE4 genotype on age at first coronary artery bypass graft (CABG), hypothesizing that patients with the apoE4 allele are predis posed to coronary artery disease and present earlier for coronary revascula rization. We assessed individual apoE genotypes and age in 560 patients und ergoing primary CABG, by using analysis of variance (ANOVA) and controlling for gender. Because of the small number of patients in individual genotype groups, we compared patients with one or more copies of the apoE4 allele w ith those having no copies of the allele, again controlling for gender. A c omparison of patients with one or more copies of the apoE4 allele with pati ents without the allele showed an earlier age at first CABG for those with the allele (P = 0.032). Gene-dose analysis was also significant (P = 0.012) ; patients with two copies of the allele presented at 54.2 +/- 6.9 yr. We r eport that the apoE4 allele is linked to age at first CABG. Identifying at- risk individuals may help prevent atherosclerosis. Further study is needed to define the mechanism of this association, and to define which coronary i ntervention is appropriate, based on longterm outcome.