Thrombus in Transit Following Hemodynamic Stabilization in Acute Pulmonary Embolism: A Therapeutic Dilemma

Risk stratification and therapeutic decision-making in acute pulmonary embolism (PE) remain challenging, particularly in patients with apparent hemodynamic stability after an initially unstable presentation. We present the case of a 61-year-old woman with a history of type 2 diabetes mellitus, hypertension, and obesity who presented with sudden-onset dyspnea and chest pain accompanied by initial hemodynamic instability and elevated lactate levels. Computed tomography pulmonary angiography confirmed bilateral PE. Although the patient subsequently achieved hemodynamic stabilization, transthoracic echocardiography demonstrated severe right ventricular dysfunction, McConnell's sign, a right heart thrombus in transit, and right ventricle-pulmonary artery uncoupling with a tricuspid annular plane systolic excursion (TAPSE)/pulmonary artery systolic pressure (PASP) ratio of 0.19. Given these findings, systemic thrombolysis was performed, resulting in clinical and echocardiographic improvement without major bleeding complications. This case highlights the limitations of hemodynamic stability as the sole criterion for risk assessment in acute PE. The presence of a right heart thrombus in transit and right ventricle-pulmonary artery uncoupling may identify patients at increased risk of deterioration despite the absence of persistent shock. Integrating clinical and echocardiographic findings may improve the recognition of concealed high-risk features and support individualized therapeutic decision-making in acute PE.