200 Patients will be identified through routine daily scanning of imaging records (CT, Echocardiography) for patients diagnosed with PE. Presenting signs and symptoms as well as clinical and imaging findings during the initial presentation and hospitalization will be incorporated into a computerized pre-specified electronic CRF. During hospitalization, an endothelial function test will be performed 48 hours post admission. A trained technician will perform the test using the EndoPAT device in order to assess patient RHI, a score less than 1.67 will be considerate as endothelial dysfunction. Patients will then be followed for pre-specified clinical events of up to 1 year post discharge and especially the development of chronic thromboembolic pulmonary disease, post thrombotic syndrome and clinical events. RHI will be assessed during 1-year follow up visit.