Incidence and Outcomes of Early Left Ventricular Thrombus Following ST-elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

Background: Since the advent of primary percutaneous coronary intervention (PCI), studies have reported a declining incidence of left ventricular thrombus (LVT) following ST-elevation myocardial infarction (STEMI). We investigated the incidence and outcomes of early (pre-discharge) LVT in the contemporary era of PCI practice in a large cohort of STEMI patients.

Methods: We retrospectively studied 2071 consecutive STEMI patients who underwent successful primary PCI. Screening echocardiography was performed within 24-48 h of admission. Patients with anterior STEMI were treated with intravenous heparin for 24-48 h until a first echocardiography test was performed. Patients with reduced ejection fraction (EF) ≤40% had a repeat test before hospital discharge (days 5-7). Heparin was continued in case of significant left ventricular dysfunction (EF < 35%) or apical akinesis or dyskinesis, until a second test ruled out LVT.

Results: LVT was diagnosed before hospital discharge in 31/2071 patients (1.5%), 28 of whom (90%) had anterior STEMI. Only 2/31 patients with LVT (6.5%) developed embolic events before discharge and 1/31 (3.2%) had an episode of upper gastrointestinal bleeding that required blood transfusion. There was no significant difference between the two groups regarding in-hospital STEMI-related complications, short- and long-term mortality. All LVTs resolved in subsequent echocardiograms within 6 months of discharge.

Conclusions: We report a low incidence of early LVT following STEMI. Further studies are needed to assess the efficacy and safety of a limited in-hospital anticoagulation protocol in STEMI patients with reduced EF.