A Case of Right Heart Failure: When It Is Not Pulmonary Embolism

Abstract A 66–year–old patient, showing exertional dyspnea and atypical chest pain, came to our attention with instrumental findings at echocardiogram of right ventricular failure and was hospitalized due to worsening signs and symptoms of right heart failure. Signs of right ventricular strain and the McGinn–White sign (S1Q3T3 pattern) were seen on the ECG, leading to the suspicion of pulmonary thromboembolism (PE). Pulmonary CT angiography confirmed bilateral PE involving the main pulmonary artery. Oral anticoagulant therapy was initiated with initial partial benefit and relief of symptoms. However, after four weeks, the patient was readmitted for severe heart failure and signs of low cardiac output. Echocardiography showed the presence of a conspicuous, mobile, isoechoic mass occupying most of the main pulmonary artery, suggesting thrombosis. The patient underwent urgent surgical thromboendoarterectomy extended to the third segmental left branches and to the second segmental right branches of the pulmonary artery; a severe pulmonary valve regurgitation was observed and therefore the valve was replaced with a Edwards–Magna pericardial bioprosthetic valve. ECMO (Extracorporeal Membrane Oxygenation) was initiated due to haemodinac instability. In the postoperative period, the severe heart failure worsened, unresponsive to pharmacological treatments and mechanical support, leading to the patient passing away in the following days. Unexpectedly, histological analysis of the surgical specimen revealed neoplastic cells with vascular/endothelial differentiation; fluorescence in situ hybridization (FISH) detected the MDM2 gene (cfr.23–F–00275), involved in the p53 protein regulation mechanisms, which is consistent with a diagnosis of angiosarcoma. Pulmonary–artery angiosarcomas are extremely rare (few anecdotical cases are described in literature) and resemble the CT–signs and clinical features of PE, seriously delaying the diagnosis. They are usually associated with a worse prognosis than PE, one and a half months survival time when inoperable. Radical surgery, associated with thirty six and a half months survival time, is often unfeasible because of locally advanced disease or metastatic disease already present at diagnosis. The main differences with PE are the more proximal and almost–occluding involvement of the pulmonary artery, the absence of peripheral vein thrombosis and the absence of response to anticoagulant therapy.