Factors influencing left ventricular thrombus resolution and its significance on clinical outcomes.

Abstract

A left ventricular thrombus (LVT) is not uncommon in patients with impaired LV systolic function. However, the treatment strategy for LVT has not yet been fully established. We aimed to identify the factors influencing LVT resolution and the significance of LVT resolution on clinical outcomes. We retrospectively investigated patients diagnosed with LVT with left ventricular ejection fraction (LVEF)<50% on transthoracic echocardiography from January 2010 to July 2021 in a single tertiary centre. LVT resolution was monitored through serial follow-up transthoracic echocardiography. The primary clinical outcome was a composite of all-cause death, stroke, transient ischaemic attack, and arterial thromboembolic events. LVT recurrence was also evaluated in patients with LVT resolution. There were 212 patients diagnosed with LVT (mean age, 60.5±14.0years; male, 82.5%). The mean LVEF was 33.1±10.9%, and 71.7% of patients were diagnosed with ischaemic cardiomyopathy. Most patients were treated with vitamin K antagonists (86.7%), and 28 patients (13.2%) were treated with direct oral anticoagulants or low molecular weight heparin. LVT resolution was observed in 179 patients (84.4%). LVEF improvement failure within 6months was a significant factor hindering LVT resolution (hazard ratio, HR: 0.52, 95% confidence interval, CI: 0.31-0.85, P=0.010). During a median 4.0years of follow-up (interquartile range, IQR: 1.9 to 7.3years), 32 patients (15.1%) experienced primary outcomes (18 all-cause deaths, 15 strokes, and 3 arterial thromboembolisms) and 20 patients (11.2%) experienced LVT recurrence after LVT resolution. LVT resolution was independently associated with a lower risk for primary outcomes (HR: 0.45, 95% CI: 0.21-0.98, P=0.045). In the patients with resolved LVT, discontinuation or duration of anticoagulation after resolution were not significant predictors for LVT recurrence, but LVEF improvement failure at LVT resolution was associated with a significantly higher risk of LVT recurrence (HR: 3.10, 95% CI: 1.23-7.78, P=0.016). This study suggests that LVT resolution is an important predictor for favourable clinical outcomes. LVEF improvement failure interfered with LVT resolution and appeared to be a crucial factor for LVT recurrence. After LVT resolution, continuation of anticoagulation did not seem to impact LVT recurrence and the prognosis.