Prognostic implications over time of platelet FcɣRIIa expression in patients with myocardial infarction: a secondary analysis.

Objectives. In patients with myocardial infarction (MI), quantifying platelet FcɣRIIa (pFCG) stratifies the risk of subsequent MI, stroke, and death. The authors conducted a secondary analysis to assess the prognostic implications of the pFCG test over the course of 1 year after MI. Methods. Patients (n = 764) hospitalized for type 1 MI (ST elevation and non-ST elevation) were enrolled in a prospective non-interventional trial. Inclusion criteria included at least 2 of the following: age 65 years or older, multi-vessel coronary artery disease, prior MI, chronic kidney disease, and diabetes mellitus. Flow cytometry was used to quantify pFCG at a core laboratory. High and low pFCG were defined by a prespecified threshold. The primary endpoint (n = 98) was the composite of MI, stroke, and death. Results. The time-to-first-event analysis demonstrated that the pFCG test had the greatest prognostic power early after MI. The hazard ratio (HR) for the primary composite endpoint in all subjects was greatest during the first month (3.84, P = .0009), and the HR for the first 6 months was 2.90 (P = .00005). Similar trends were apparent for patients treated with percutaneous coronary intervention and those treated with medical therapy alone. Analysis of components of the primary endpoint, the composite of MI and death, as well as MI alone, showed similar trends. Conclusions. The pFCG test is a powerful prognostic marker of ischemic risk during the first 6 months after MI. The prognostic information provided by the pFCG test should be useful to clinicians as they balance risk of ischemic events with that of bleeding to define a treatment strategy.