Left ventricular thrombus is found in 10 to 25% of patients with impaired left ventricular function following ST-segment elevation myocardial infarction and up to 20% in dilated cardiomyopathy in observational studies. Likewise, the incidence of atrial thrombus among atrial fibrillation patients treated by vitamin K antagonist (VKA) is between 0.25% and 7%. Despite anticoagulant therapy, intra-cardiac thrombus remains a severe complication associated with a high risk of systemic embolism and subsequent mortality but also bleeding events related to the anticoagulation therapy. The class of non-vitamin K antagonist direct oral anticoagulant (DOA) has emerged in the last decades and has systematically surpassed VKA in the different clinical settings by providing at minimum a similar efficacy and a better safety profile. In the absence of randomized study in the specific clinical setting of intracardiac thrombus, international Guidelines recommend, on the basis of expert opinion, the use of VKA for at least 3 to 6 months in case of left ventricular thrombus and there is no specific recommendation for thrombus management from other cardiac localizations.
In comparison to VKA, the easier management and the large evidence of better safety of DOA make it an interesting anticoagulant strategy. Data for left ventricule thrombosis treatment are limited and only supported by observational cohorts. However, these recent cohorts have shown promising data in this indication reporting similar thrombus regression following DOA in comparison to VKA and similar ischemic outcomes although no head-to-head comparison would be powered.
As a consequence, the multicentric randomized ARGONAUT trial aims to confirm these results and evaluate the impact of DOA compared to VKA on thrombus regression and clinical outcomes among patients with intracardiac thrombus, regardless of the thrombus localization and any underlying heart disease.
