Evaluation of Safety of Warfarin in Combination with Antiplatelet Therapy for Patients Treated with Coronary Stents for Acute Myocardial Infarction

Abstract

The safety and efficacy of treating recently stented patients on combination antiplatelet therapy with warfarin for clinical indications in unknown. Therefore, we examined the use of warfarin in a population of patients with myocardial infarction (MI) treated with coronary stenting. We performed a retrospective analysis comparing patients who underwent successful coronary stenting for acute MI and were discharged on either warfarin and combination platelet therapy for clinical indications or combination antiplatelet therapy alone. There was a nonsignificant trend toward reinfarction at 6 and 12 months in warfarin-treated patients. Warfarin-treated patients had significantly higher rates of transfusion compared to nonwarfarin-treated patients at 12 months (21% vs 0%, P=0.028). There were no significant predictors of reinfarction in 6 and 12 months in multivariate analysis. These data demonstrate that warfarin anticoagulation, in combination with successful coronary stenting for acute MI and antiplatelet therapy, does not reduce risk of reinfarction but is associated with increased rates of transfusion.