title: Association between platelet P2Y12 haplotype and risk of cardiovascular events in chronic coronary disease.
abstract: BACKGROUND
  A positive association was recently described between P2Y12 platelet receptor H1 and H2 haplotypes and peripheral artery disease. We tested the described P2Y12 receptor haplotypes in a group of patients with coronary artery disease.
  
  
  METHODS
  The P2Y12 platelet receptor H1 and H2 haplotypes was tested in a group of 540 patients enrolled in the Medical, Angioplasty, or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease (CAD) and preserved left ventricular function. After a 3-year follow-up period, the incidence of the composite end point of cardiac death, myocardial infarction, and refractory angina requiring revascularization was determined in the H1/H1, H1/H2 and H2/H2 haplotype groups. We used Student's t-test and the chi-square test to analyze the differences among groups and Kaplan-Meier method to calculate survival curves. Risk was assessed with the use of a Cox proportional-hazards model.
  
  
  RESULTS
  The frequency of haplotypes among studied patients were 410 (75.9%) H1/H1, 119 (22.0%) H1/H2 and 11 (2.1%) H2/H2. The baseline clinical characteristics, mean clinical follow-up time and received treatment of each genotype group were similar. We did not disclose any association between haplotype groups regarding the incidence of any of the studied cardiovascular end-points.
  
  
  CONCLUSIONS
  This is the first report studying the association of P2Y12 platelet receptor H1 and H2 haplotype and cardiovascular events. Our findings do not provide evidence for a strong association between H1/H1 and H1/H2 haplotypes and a increased risk of cardiovascular events in a population with CAD. Future works should address the role of the H2/H2 haplotype as a genetic marker for cardiovascular events.
authors.affiliation: Heart Institute, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Isolmar T
authors.initials: IT
authors.lastname: Schettert
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Pereira
authors.forename: Neuza H
authors.initials: NH
authors.lastname: Lopes
authors.forename: Whady A
authors.initials: WA
authors.lastname: Hueb
authors.forename: Jose E
authors.initials: JE
authors.lastname: Krieger
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000235:genetics*; D003324:Coronary Artery Disease / Q000150:complications / Q000235:genetics* / Q000401:mortality; D005260:Female; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000235:genetics*; D016016:Proportional Hazards Models; D018048:Receptors, Purinergic P2 / Q000235:genetics*; D058925:Receptors, Purinergic P2Y12
chemical_list: C548576:P2RY12 protein, human; D018048:Receptors, Purinergic P2; D058925:Receptors, Purinergic P2Y12