Pl A Polymorphism of Platelet Glycoprotein IIIa and Risk of Restenosis After Coronary Stent Placement

Background —Platelets play a central role in the process of restenosis after percutaneous coronary interventions. A polymorphism of platelet glycoprotein IIIa (Pl A ) has been associated with a higher risk of coronary thrombosis. We designed this prospective study to test the hypothesis that Pl A polymorphism of glycoprotein IIIa is associated with an increased risk for restenosis after coronary stent placement. Methods and Results —The study included 1150 consecutive patients with successful coronary stent placement and 6-month follow-up with coronary angiography. The end point of the study was the incidence of angiographic restenosis (≥50% diameter stenosis) at follow-up. Of the 1150 patients, 72.5% were homozygous for Pl A1 , 24.7% were heterozygous (Pl A1/A2 ), and 2.8% were homozygous for Pl A2 . Patients with the Pl A2 allele demonstrated a significantly higher restenosis rate than did those without (47% versus 38%; OR, 1.42; 95% CI, 1.09 to 1.84). The risk was highest in homozygous carriers of Pl A2 (53.1% restenosis rate). After adjustment for several clinical and angiographic characteristics, the presence of the Pl A2 allele remained a significantly independent risk factor for restenosis (adjusted OR, 1.35; 95% CI, 1.07 to 1.70). The influence of the Pl A2 allele on restenosis was stronger in women. Women with Pl A2 had a restenosis rate of 52% compared with the 33% incidence among women homozygous for Pl A1 (OR, 2.21; 95% CI, 1.27 to 3.85). Conclusions —This study showed a significant association between the Pl A polymorphism of glycoprotein IIIa and the risk of restenosis after coronary stent placement. The risk was more pronounced in patients homozygous for Pl A2 allele and in female patients.