Background:Patients with anterior acute myocardial infarction (AMI) and left ventricular (LV) dysfunction have an increased risk of LV thrombus (LVT). In the thrombolytic era, short-term anticoagulation using low-molecular-weight heparin during hospitalization proved to significantly reduce LVT formation, but, the effect of this prophylactic approach remains unclear in the current era. Therefore, we conducted a study to evaluate the effects of post-procedural anticoagulation (PPAC) using enoxaparin in addition to dual antiplatelet therapy (DAPT) after primary percutaneous coronary intervention (PCI) in such patients.

Methods and Results:A total of 426 anterior AMI patients with LV ejection fraction ≤40% were retrospectively enrolled and classified into 2 groups based on whether they received PPAC (enoxaparin SC for at least 7 days). All patients received primary PCI and DAPT. The primary endpoint was definite LVT at 30 days diagnosed by echocardiography. The secondary endpoints were 30-day mortality, embolic events, and major bleeding events. PPAC was independently associated with a lower incidence of LVT (odds ratio 0.139, 95% confidence interval 0.032−0.606, P=0.009). The 30-day mortality, embolic events, and major bleeding events were not statistically different between groups.

Conclusions:Short-term PPAC using enoxaparin after primary PCI may be an effective and safe way to prevent LVT in patients with anterior AMI and LV dysfunction.