Warfarin after anterior myocardial infarction in current era of dual antiplatelet therapy: a randomized feasibility trial

In the current era of early revascularization and routine use of dual antiplatelet therapy, the incremental benefit of warfarin to reduce the incidence of left ventricular thrombus (LVT) in patients with impaired left ventricular ejection fraction post anterior ST-elevation myocardial infarction (aSTEMI), remains uncertain. The purpose of this study is to assess the feasibility of evaluating the added benefit and safety of triple therapy (TT-warfarin, ASA, and clopidogrel) versus dual therapy (DT-ASA and clopidogrel) in patients at risk of LVT post aSTEMI. Design: Open-label randomized controlled trial. Inclusion: aSTEMI, ejection fraction <40%, and no evidence of LVT. Exclusion: contraindication to, or alternate indication for anticoagulation. Intervention: TT versus DT. Follow-up: pre-discharge and 3 month echocardiogram. Outcomes: composite of death, MI, stroke, systemic embolizarion, LVT or major bleeding at three months. 295 patients with aSTEMI were screened: 27% of patients with LVEF < 40% had an LVT; 20/52 eligible patients were randomized to receive TT (n = 10) or DT (n = 10). Baseline characteristics: mean age 60 years, male gender 65%, diabetics 20%, and in hospital PCI 95%. There was no significant difference in the composite endpoint at 3 months (TT-20% with 1 LVT and 1 major bleed versus DT-10% with 1 MI). The incidence of definite or probable LVT in the screened population of patients post aSTEMI with an LVEF < 40% was 26.6% despite 94% having early revascularization. STEMI patients have a high incidence of LVT despite the routine use of early revascularization and dual antiplatelet therapy. More effective antithrombotic strategies merit evaluation in adequately powered randomized trials.