BackgroundLeft ventricular thrombus (LVT) can develop in a diverse group of patients with various underlying causes resulting in divergent natural histories and trajectories with treatment. Our aim was to utilise cluster analysis to identify unique clinical profiles among LVT patients and then compare their clinical characteristics, treatment strategies, and outcomes. MethodsWe conducted a retrospective study involving 472 LVT patients whose data was extracted from a tertiary center's echocardiography database, from March 2011 to January 2021. We employed the TwoStep cluster analysis method, examining 19 variables. ResultsOur analysis of the 472 LVT patients revealed two distinct patient clusters. Cluster 1, comprising 247 individuals (52.3%), was characterized by younger patients with a lower incidence of traditional cardiovascular risk factors and relatively fewer comorbidities, compared to Cluster 2. Most patients had LVT attributed to an underlying ischaemic condition, with a larger proportion in Cluster 1 being due to post-acute myocardial infarction (68.8%), and Cluster 2 due to ischaemic cardiomyopathy (57.8%). Notably, patients in Cluster 2 exhibited a reduced likelihood of LVT resolution (HR 0.58, 95% CI 0.44 – 0.77, p < 0.001) and a higher risk of all-cause mortality (HR 2.27, 95% CI 1.43 – 3.60, p = 0.001). These associations persisted even after adjusting for variables like anticoagulation treatment, the presence of left ventricular aneurysms, and specific LVT characteristics such as mobility, protrusion, and size. ConclusionsThrough TwoStep cluster analysis, we identified two distinct clinical phenotypes among LVT patients, each distinguished by unique baseline clinical attributes and varying prognoses.