Effect of glycoprotein IIIa PIA2 polymorphism on outcome of patients with stable coronary artery disease and effect of smoking

A polymorphism of glycoprotein IIb/IIIa has been associated with myocardial infarction and restenosis after percutoneous coronary intervention. The influence on outcome and the interaction of the PIA1 genotype with classic risk factors for coronary artery disease (CAD) were characterized in patients with chronic CAD followed prospectively for 3 years. PIA1 genotypes were assessed in 592 patients enrolled in the Medical, Angioplosty, or Surgery Study II, a randomized trial comparing treatments for patients with CAD and preserved left ventricular function. The incidence of the composite end point of cardiac death, myocardial infarction, and refractory angina requiring revascularization were determined in each genotype group. Risk was assessed with the Cox proportional-hazards model. The clinical characteristics and treatment of each genotype were similar. Although the composite end point tended to be more common in patients with the PIA2 allele, only smokers with the PIA2 allele had a significantly increased incidence of the composite end point (p = 0.01). Moreover, a 2.2-fold increased risk was apparent in smokers with the PIA2 allele (p = 0.03). Thus, taken together, these data provide support for the interaction effect between smoking and the PIA1 gene variant. Smokers with the PIA2 polymorphism of platelet glycoprotein Ilia are at greater risk for subsequent cardiac events in stable coronary disease. (C) 2004 by Excerpta Medica, Inc.