LV Thrombus Screening in Anterior STEMI: Worth it?

Overview

Left ventricular (LV) thrombus is more common in patients with anterior ST-elevation myocardial infarction (STEMI) compared to other types of acute myocardial infarction (AMI) and is linked to worse outcomes. Diagnosing LV thrombus remains challenging. Contrast echocardiography (TTE) has potential to improve diagnostic accuracy, affecting treatment strategies involving antithrombotic/anticoagulation therapy. This study aimed to evaluate the effectiveness of contrast TTE as a routine screening method for detecting LV thrombus in the acute phase of anterior STEMI.

The advent of primary percutaneous coronary intervention (PCI) has significantly lowered mortality rates associated with acute myocardial infarction (AMI). Despite these advancements, post-infarction complications, including left ventricular (LV) thrombus, continue to negatively impact prognosis. The incidence of LV thrombus has decreased due to improved reperfusion techniques and antithrombotic therapies; however, it remains a significant risk factor for embolic events, with up to a 10% risk of stroke within a year despite anticoagulation therapy. The formation of thrombus post-AMI, particularly in anterior ST-elevation myocardial infarction (STEMI), is driven by endothelial injury, blood stasis due to LV dysfunction, and hypercoagulability from inflammation. Anterior STEMI, usually caused by occlusion of the left anterior descending artery, often leads to LV apical akinesia and subsequent thrombus formation within 24 hours to two weeks post-AMI. Guidelines recommend routine transthoracic echocardiography (TTE) post-PCI to evaluate LV function and detect early post-infarction mechanical complications and LV thrombus. However, conventional TTE can be limited by operator skill and may miss thrombi, especially in cases with suboptimal images or small/mural thrombi. Advances in ultrasound technology, including contrast agents, have improved diagnostic accuracy for LV thrombus by enhancing LV opacification and endocardial border delineation, thus identifying the characteristic "filling defect" of intracardiac thrombus. This study aimed to assess the effectiveness of contrast-enhanced TTE as a routine screening method for detecting LV thrombus in the acute phase of anterior STEMI. A prospective, single-center, randomized controlled trial was conducted with patients admitted for anterior STEMI at Centro Hospitalar de Tondela-Viseu from November 2021 to January 2023. Patients were randomly assigned to a study group (undergoing contrast TTE) or a control group (undergoing conventional TTE). Exclusion criteria included patients under 18, those without echocardiographic or coronary angiographic evaluation, those with cardiogenic shock, known thrombus, or allergic reactions to contrast agents. Contrast TTE utilized the SonoVue ultrasound agent and GE i9 echocardiograph, performed by specialized cardiologists. Data collected included demographic, clinical, and procedural information, with statistical analysis comparing the characteristics and outcomes between the two groups.