Resolution of Left Ventricular Thrombus Assessed by Echocardiography: Insights from a Contemporary Multicenter Prospective Registry

Abstract Background How to detect and monitor left ventricular thrombus (LVT) remains complex since clinicians can rely only on retrospective, single-center data. Objectives To characterize the incidence and independent associates of LVT resolution (assessed with echocardiography) and its clinical implications on long-term follow-up in a contemporary cohort of consecutive patients with LVT. Methods Ten centers were involved in this observational prospective multicenter study. The use of different antithrombotic regimens and ultrasound contrast was left at the discretion of attending physicians. Echocardiographic follow-up was performed on days 16±8, 48±13, and 132±99 days from LVT detection. Resolution was defined as a complete disappearance of LVT on all echocardiographic views at the last available follow-up. Clinical endpoints included all-cause mortality, embolic complications, and bleeding events. Results From October 2020 to September 2022, 154 consecutive patients with LVT (mean age 67±11 years, 79% men) were enrolled. Different anticoagulant regimens were used, and the median duration of anticoagulation was 6 (3-12) months. LVT resolution was achieved in 68% at a median follow-up of 36 (IQR15-74) days. At baseline assessment, LVT characteristics like smaller LVT area and mobile LVT were independent predictors of LVT resolution. At follow-up echocardiogram, greater LV global and apical mechanical function were independently associated with LVT resolution (OR, 1.04, 95%CI 1.01-1.07, p=0.026 for LVEF and 0.94, 95%CI 0.89-0.99, p=0.025 for apical wall motion score index). During a median follow-up of 1.91 (IQR, 1.32-2.83) years, patients with LVT resolution showed a significantly lower risk of embolic events (adjusted HR, 0.36 95%CI 0.13-0.99, p=0.04) and death (adjusted HR, 0.36 95%CI 0.14-0.95, p=0.03) compared with those without resolution. Moreover, LVT resolution was not associated with bleeding complications. Conclusions The present longitudinal multicenter registry reveals that LVT persists in nearly one-third of patients after initial detection, even with anticoagulation therapy, and is associated with a poorer prognosis. Additionally, it offers valuable insights into echocardiographic predictors of LVT persistence, which could inform personalized follow-up strategies and treatment approaches.