Contemporary early left ventricular thrombus resolution by echocardiography: insight from a longitudinal multicenter registry

Abstract Funding Acknowledgements Type of funding sources: None. Background Multicenter longitudinal data are lacking regarding the incidence and the time needed for total left ventricular thrombus (LVT) regression obtained with contemporary antithrombotic regimens diagnosed with modern echocardiographic technology. Purpose To quantify the effect of antithrombotic therapy on LVT evolution using sequential up-to-date echocardiography in a large cohort of patients with LVT. Methods Ten centers were involved in this observational prospective multicenter study. LVT was defined as an echo-dense mass adjacent to a hypokinetic or akinetic myocardial segment. To be distinguishable from the underlying myocardium, a clear thrombus–blood interface was required and the LVT had to be visible on at least 2 views during the cardiac cycle. Initial follow-up echocardiograph was scheduled at 14±7 days (T0) and 42±7 days (T1). The early resolution was defined when LVT was no longer detected at T1. The use of different anticoagulant regimens and ultrasound contrast was left at the discretion of attending physicians, according to good clinical practice. Results From October 2020 to November 2022, 99 patients with LVT (mean age 66 ± 11 years, 80% men) were identified with echocardiography, in 53% ultrasound contrast was used. Early resolution of LVT was observed in 42%. Echocardiographic characteristics by early resolution of LVT are shown in Table. The independent correlates of early LVT regression were smaller baseline LVT area, higher LVEF, and mobile LVT (p<0.05). Conclusions In this large and well-characterized present-day cohort of patients with LVT, early regression by echocardiography was achieved in less than half of the patients and was mostly related to the size of the LVT and heart function rather than treatment despite a high proportion of antithrombotic therapy. The next step will be to assess the impact of LVT persistence on subsequent clinical outcomes.