Summary
Background: G to A transitions at nucleotide position 20210 of the factor II (FII)
gene and at 1691 of the factor V (FV) gene have been shown to be associated with an
increased risk of venous thrombosis. Since it is still unclear whether both gene variations
are also related to an increased risk of coronary heart disease (CHD), we studied
the relation of both gene variations to coronary artery disease (CAD) and myocardial
infarction (MI) in a sample of 2210 male individuals whose coronary anatomy were defined
by coronary angiography.
Results: In the total sample, the FII G20210A gene variation was not associated with
the presence or the extent of CAD, the latter defined either by the degree of vessel
disease or by a CHD score according to Gensini. However, individuals with unfavourable
lipid profiles showed pronounced differences in CHD scores between GA heterozygotes
and GG homozygotes; this observation applied in particular to younger patients (<62
years; mean age of total sample) who simultaneously had low apoAI/apoB ratios (< 1.19,
mean value) and high Lp(a) plasma levels (>28 mg/dl; mean value). In addition, in
subjects without acetylsalicylic acid treatment GA heterozygotes had clearly higher
CHD scores than AA genotypes. Further restriction to smokers, to subjects with high
fibrinogen plasma levels (>3.47 g/l; mean value) or to patients with high glucose
concentrations (>112 mg/dl; mean value) tended to increase the difference in CHD score
between FII G20210A genotypes. An association of the FII G20210A gene variation with
nonfatal MI was not observed. In the total sample and in high and low risk subpopulations,
an association of the FV G1691A gene variation was not detected neither with presence
and extent of CAD or with nonfatal MI.
Conclusion: The importance of the factor II G20210A gene variation for CHD may be
restricted to individuals with major cardiovascular risk factors. In addition, the
present study did not strengthen the hypothesis of the factor V G1691A transition
as a risk factor of coronary heart disease neither in the total sample nor in subgroups
of individuals who were at high or low risk of CHD.