The platelet polymorphism PlA2 is a genetic risk factor for myocardial infarction.
OBJECTIVE
Platelet glycoprotein (GP) receptor IIb/IIIa plays a key role in the development of myocardial infarction (MI), and Pl(A2) is a polymorphism in the gene encoding this receptor. The prevalence of Pl(A2) shows pronounced geographical variation and has to our knowledge not been presented for a Scandinavian population before. Platelets from Pl(A2)-positive individuals show increased aggregability compared with platelets from Pl(A2)-negative individuals, and Pl(A2) genotypes might be associated with MI. The purpose of this study was to investigate the relation between the Pl(A2) polymorphism and MI in a large Scandinavian population.


METHODS
Case-control study. We included patients with angiographically verified CAD with and without previous MI and a group of healthy individuals matched for age, race, and sex.


RESULTS
We studied the frequency of Pl(A2) in 1191 healthy individuals and 1019 patients with coronary artery disease (CAD). Amongst these patients, 529 subjects had suffered an MI previously. Pl(A2) was present in 28% of healthy individuals, 28% of patients with CAD but no MI, and in 35% of patients with CAD and MI. The difference between healthy individuals and MI patients was significant (P = 0.002). Furthermore, a graded relationship between the number of Pl(A2) alleles and the risk of MI was seen (P = 0.011). Associations between Pl(A2) and traditional cardiovascular risk factors as well as mean platelet volume were investigated. We found a significant interaction between Pl(A2) and serum cholesterol.


CONCLUSIONS
In our Scandinavian study population the common platelet polymorphism Pl(A2) is significantly associated with an increased risk of MI, but not of CAD. Clinically, typing for Pl(A2) might have implications for antiplatelet therapy of patients with MI.
Grove
E L
EL
Department of Cardiology, Aarhus University Hospital, Skejby Sygehus, Denmark.
Ørntoft
T F
TF
Lassen
J F
JF
Jensen
H K
HK
Kristensen
S D
SD
D000483:Alleles; D016824:Antigens, Human Platelet / Q000235:genetics*; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D003324:Coronary Artery Disease / Q000235:genetics*; D023921:Coronary Stenosis / Q000235:genetics; D005192:Family Health; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000235:genetics*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012307:Risk Factors
D016824:Antigens, Human Platelet; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C083451:human platelet antigen 1b; D002784:Cholesterol