Current guidelines recommend the use of vitamin K antagonist (VKA) for up to 3-6 months for treatment of left ventricular (LV) thrombus post-acute myocardial infarction (AMI). However, based on evidence supporting non-inferiority of novel oral anticoagulants (NOAC) compared to VKA for other indications such as deep vein thrombosis, pulmonary embolism (PE), and thromboembolic prevention in atrial fibrillation, NOACs are being increasingly used off licence for the treatment of LV thrombus post-AMI. In this study, we investigated the safety and effect of NOACs compared to VKA on LV thrombus resolution in patients presenting with AMI.

This was an observational study of 2328 consecutive patients undergoing coronary angiography ± percutaneous coronary intervention (PCI) for AMI between May 2015 and December 2018, at a UK cardiac centre. Patients' details were collected from the hospital electronic database. The primary endpoint was rate of LV thrombus resolution with bleeding rates a secondary outcome. Left ventricular thrombus was diagnosed in 101 (4.3%) patients. Sixty patients (59.4%) were started on VKA and 41 patients (40.6%) on NOAC therapy (rivaroxaban: 58.5%, apixaban: 36.5%, and edoxaban: 5.0%). Both groups were well matched in terms of baseline characteristics including age, previous cardiac history (previous myocardial infarction, PCI, coronary artery bypass grafting), and cardiovascular risk factors (hypertension, diabetes, hypercholesterolaemia). Over the follow-up period (median 2.2 years), overall rates of LV thrombus resolution were 86.1%. There was greater and earlier LV thrombus resolution in the NOAC group compared to patients treated with warfarin (82% vs. 64.4%, P = 0.0018, at 1 year), which persisted after adjusting for baseline variables (odds ratio 1.8, 95% confidence interval 1.2-2.9). Major bleeding events during the follow-up period were lower in the NOAC group, compared with VKA group (0% vs. 6.7%, P = 0.030) with no difference in rates of systemic thromboembolism (5% vs. 2.4%, P = 0.388).

These data suggest improved thrombus resolution in post-acute coronary syndrome (ACS) LV thrombosis in patients treated with NOACs compared to VKAs. This improvement in thrombus resolution was accompanied with a better safety profile for NOAC patients vs. VKA-treated patients. Thus, provides data to support a randomized trial to answer this question.