New left ventricular thrombus and embolic events in left ventricular dysfunction postmyocardial infarction

Background: We aimed to assess the incidence and evolution of new left ventricular thrombus (LVT), and the incidence of manifest systemic embolism, in patients with severe left ventricular (LV) systolic dysfunction postacute anterior myocardial infarction (MI) who had been discharged on dual antiplatelet therapy. Methods: We prospectively included consecutive patients with postacute anterior MI and LV ejection fraction (LVEF) ≤35% or apical aneurysms or large infarctions with LVEF ≤40%. Transthoracic echocardiography (TTE) confirmed no LVT before hospital discharge, and a second TTE was performed at 30 days and a third one at 3 months. All TTE studies were prespecified to assess LVT, and the patients were screened for the development of clinically manifest systemic embolisms. Results: Two hundred and two consecutive patients (males 93%; mean age 55.2±6.4 years; mean LVEF 29.5±5.0%) were included. At 30 days (interquartile range: 2837 days), a new LVT was detected in 12 (5.9%) patients. Oral anticoagulant was added to all patients with LVT, and aspirin was continued in 5 (42.7%) patients for a month. The 3month TTE showed favorable evolution of LV size, LVEF and apical wall motion score index compared to the baseline. At 3 months, the LVT disappeared in 7 (58.3%) patients and 5 patients still had a mural LVT of smaller size, and none got new LVT. Among the group without LVT, one patient had a stroke, and another had a myocardial infarction and died. Conclusions: In contemporary practice, and using routine TTE, the incidence of new LVT in patients with severe LV dysfunction postacute anterior MI is low. They have a favorable LVT evolution with minor risk for clinically manifest systemic embolism.