An exploratory study of effectiveness and safety of rivaroxaban in patients with left ventricular thrombus (R-DISSOLVE)

Abstract

Evidence on the treatment for left ventricular (LV) thrombus is limited and mainly derives from retrospective studies. The aim of R-DISSOLVE was to explore the effectiveness and safety of rivaroxaban in patients with LV thrombus. R-DISSOLVE was a prospective, interventional, single-arm study, conducted from Oct 2020 to June 2022 at Fuwai Hospital, China. Patients with a history of LV thrombus < 3 months and with systemic anticoagulation therapy < 1 month were included. The thrombus was quantitatively confirmed by contrast-enhanced echocardiography (CE) at baseline and follow-up visits. Eligible patients were assigned to rivaroxaban (20 mg once daily or 15 mg if creatinine clearance was between 30 and 49 mL/min) and its concentration was determined by detecting anti-Xa activity. The primary efficacy outcome was the rate of LV thrombus resolution at 12 weeks. The main safety outcome was the composite of ISTH major and clinically relevant non-major bleeding. A total of 64 patients with complete CE results were analyzed for efficacy outcomes. The mean LV ejection fraction was 25.4 ± 9.0%. The dose-response curve of rivaroxaban was satisfactory based on the peak and trough plasma levels and all concentrations were in the recommended treatment range according to NOAC guidelines. The incidence rate of thrombus resolution at 6 weeks was 66.1% (41/62, 95% CI 53.0-77.7%), and of thrombus resolution or reduction was 95.2% (59/62, 95% CI 86.5-99.0%). At 12 weeks, the thrombus resolution rate was 78.1% (50/64, 95% CI 66.0-87.5%) while the rate of thrombus resolution or reduction was 95.3% (61/64, 95% CI 86.9-99.0%). The main safety outcome occurred in 4 of 75 patients (5.3%) (2 ISTH major bleeding and 2 clinically relevant non-major bleeding). In patients with LV thrombus, we reported a high thrombus resolution rate with acceptable safety by rivaroxaban, which could be a potential option for further LV thrombus treatment.Trial registration This study was registered at ClinicalTrials.gov as NCT04970381.

Keywords: Contrast-enhanced echocardiography; Left ventricular thrombus; Non-vitamin K antagonist oral anticoagulants; Rivaroxaban; Thrombus resolution.