PlA polymorphism of glycoprotein IIIa and risk of adverse events after coronary stent placement

OBJECTIVE We designed this prospective study to test the hypothesis that platelet antigen (P1(A)) polymorphism of glycoprotein (GP) IIIa is associated with an increased risk for adverse events after coronary stent placement. BACKGROUND Platelets play a central role in arterial thrombosis. The P1(A) polymorphism of GP IIIa, a constituent of the fibrinogen receptor, may influence the platelet function and, thereby, the early outcome of patients after coronary stent placement. METHODS The study included 1,759 consecutive patients with stable or unstable angina and successful coronary stent placement. Platelet antigen genotypes were determined by allele-specific restriction enzyme analysis. The end point of the study was a composite of death, myocardial infarction and urgent revascularization during the first 30 days after stent placement. RESULTS The P1(A) genotype of the patients included was: 70.2% were homozygous for platelet antigen 1 (P1(A1)), 2.6% homozygous for platelet antigen 2 (P1(A2)), and 27.2% were heterozygous (p1(A1/A2)). The incidence of the composite end point was 5.5% among P1(A2) carriers and 5.4% in homozygous P1(A1) subjects (p = 0.94). It was 5.4% in p1(A1/A1) patients, 4.8% in p1(A1/A2) patients and 13.0% in P1(A2/A2) patients (P = 0.06). The combined incidence of death or myocardial infarction was 4.3% in P1(A1/A2) p1(A2/A2) patients (p = 0.02). CONCLUSION The isolated presence of the p1(A2) allele in heterozygous patients is not associated with anp detectable increase in the risk for an adverse 30-day outcome after coronary stenting. This study suggests also that an increased risk is likely to be present in homozygous carriers of the P1(A2) allele, but this should be confirmed in a much larger series of patients. (J Am Coil Cardiol 2000;36: 84-9) (C) 2000 by the American College of Cardiology.