Apolipoprotein E polymorphism is not a predictor for repeated coronary artery bypass surgery.
OBJECTIVE
Factors leading to the occlusion of coronary grafts are diverse and may at least partially be inherited. We aimed to study the possible genetic predisposition and especially the role of apoE epsilon4 allele as a risk factor for repeated coronary artery bypass grafting (CABG) in a case-control setting.


METHODS
All patients (n=184) who underwent repeated CABG between 1990 and 1998 were identified in the computed registry of the Department of Cardiothoracic Surgery in Tampere University Hospital. Age, sex and operation date matched controls with first time CABG were selected from the same registry. DNA samples were collected by sample stick sent via the mail for buccal smear. The final analysis included 137 surviving matched pairs.


RESULTS
In patients <62 years of age (median age), family history emerged as the only significant (OR=3.4; 95% CI=1.5-7.8, p=0.004) predictor for repeated surgery. Among older patients, repeated CABG was no longer predicted by family history but by hypercholesterolemia (OR=2.1; 95% CI=1.1-4.0, p=0.027), modified by apoE genotype.


CONCLUSIONS
Our results suggest that medium-term survivors after redo CABG have a strong genetic predisposition unrelated to hypercholesterolemia or apoE genotype, leading to more severe coronary artery disease at earlier age. In the older age group, redo coronary artery bypass surgery is associated with hypercholesterolemia, which, although modified by apoE genotype, may mainly be due to other genetic or acquired factors.
Kuukasjärvi
Pekka
P
Heart Center, Tampere University Hospital and Medical School, University of Tampere, Finland. pekka.kuukasjarvi@uta.fi
Tarkka
Matti
M
Mennander
Ari
A
Ilveskoski
Erkki
E
Koivisto
Anna-Maija
AM
Laippala
Pekka
P
Mikkelsson
Jussi
J
Karhunen
Pekka J
PJ
D000368:Aged; D001057:Apolipoproteins E / Q000235:genetics*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000097:blood / Q000235:genetics* / Q000601:surgery*; D005260:Female; D005387:Finland; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000235:genetics / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012086:Reoperation; D016896:Treatment Outcome
D001057:Apolipoproteins E; D015415:Biomarkers; D002784:Cholesterol