The role of aetiology in determining anticoagulation effectiveness for the treatment of Left Ventricular Thrombus

Abstract Background Left ventricular (LV) thrombus is a severe complication of acute myocardial infarction (AMI) and chronic heart failure. While current guidelines support the use of direct oral anticoagulants (DOAC) as alternatives to vitamin K antagonists (VKA), their benefit across different aetiologies remains uncertain. This study aimed to compare the efficacy and safety of DOAC versus VKA across different aetiologies of LV dysfunction. Methods We conducted a multi-centre observational study including 901 patients with confirmed LV thrombus treated with either a VKA or DOAC. The primary outcome was thrombus resolution, secondary outcomes included stroke and systemic embolisation (SSE), major bleeding and mortality with analyses performed by aetiology. Results The principal aetiologies were AMI (38.3%), ischaemic cardiomyopathy (ICM) (38.0%) and non-ischaemic cardiomyopathy (NICM) (23.7%). Overall, thrombus resolution was significantly higher in DOAC treated patients, but this was driven by the AMI sub-group (p=0.018). DOAC use independently predicted thrombus resolution (OR 2.0, 95% Cl 1.29-3.24, p=0.010). Major bleeding events (BARC ≥3) were more common with VKA use (p=0.008). NICM had the highest SSE rate (15.3%, p=0.002), which were significantly raised in those treated with DOAC (p<0.001). Conclusions The underlying aetiology of LV dysfunction significantly influences both treatment response and outcomes in patients with LV thrombus. DOAC were associated with superior efficacy and safety in AMI-related LV thrombus, but were linked to increased rates of SSE in NICM. These findings highlight the importance of aetiology on LV thrombus management and the potential need for tailored approaches.