Prognostic Significance of Echocardiography-Visualized Thrombus in Right Heart in Early Stages of Acute PE: 100 Patients from Regional Pulmonary Embolism Registry

Background: The significance of imaging right-heart thrombus via echocardiography in acute pulmonary embolism (PE) patients, as well as its management, remains uncertain. Methods: In this retrospective, observational, multicenter, and multinational registry of consecutive acute PE patients, we compared 100 patients in whom thrombus was visualized in the right heart during echocardiographic evaluation with 2635 patients without visualization of thrombus. The co-primary endpoints were all-cause in-hospital mortality and PE-related mortality. Secondary endpoints included the prevalence of severe PE at admission (intermediate–high and high-risk PE), the frequency of thrombolytic therapy administration, and mortality among patients who received thrombolysis. Results: All-cause and PE-related mortality were higher in patients with thrombus in the right heart (31.0% vs. 9.6%, and 25.8% vs. 5.6%, p < 0.001, respectively). Patients with right-heart thrombi had a more severe PE presentation than those without (74.0% vs. 45.3%, p < 0.001). In patients treated with thrombolysis, all-cause mortality was higher in patients with right-heart thrombi (35.5% vs. 12.7%, p < 0.001). In the multivariable Cox regression analysis adjusted for ESC mortality risk, age, presence of syncope, atrial fibrillation, and hypoxemia, patients with thrombus in the right heart had a significantly higher risk of all-cause and PE-related death compared to patients without thrombus (HR 2.60, 95% CI 1.753–3.859, p < 0.001, and HR 3.287, 95% CI 2.056–5.253, p < 0.001, respectively). Conclusions: Visualization of thrombus in transit through the right heart is associated with higher all-cause and PE-related mortality, independent of PE severity and the use of thrombolytic therapy.