In-Hospital Pulmonary Thromboembolism Development by Disease at Admission　― A Nationwide, Retrospective, Observational Study Using Japanese Claims Data ―

Background: Prevention of death from in-hospital pulmonary thromboembolism (PE) is crucial, but research exploring the risk factors for this event remains limited. Methods and Results: This retrospective analysis evaluated PE data among hospitalized patients, focusing on the diseases present on admission to hospital with the highest number of patients with in-hospital PE events, using the Medical Data Vision database (January 2017-December 2021). Endpoints included the incidence rate of in-hospital PE, patient characteristics, and PE prophylactic procedures. Overall, 4,684,659 patients (in-hospital PE cohort, n=5,007; non-PE cohort, n=4,679,952) were eligible: heart failure (n=208; n=87,160), femoral fracture (n=478; n=139,049), pneumonia (n=309; n=222,257), stroke (n=351; n=248,805), and cancer (n=934; n=764,413). The incidence rate of in-hospital PE in the overall population was 20.6/1,000 person-years: heart failure (34.6), femoral fracture (35.3), pneumonia (21.4), stroke (15.9), and cancer (25.6). History of venous thromboembolism (VTE) was a risk factor for in-hospital PE in >50% of patients in all subgroups. Prophylactic PE procedures were implemented in 33.8% of the overall population: femoral fracture (79.5%), cancer (49.7%), stroke (24.2%), heart failure (12.7%), and pneumonia (6.2%). Conclusions: The incidence of in-hospital PE was not high overall but was higher in patients with a history of VTE and those with hospitalization due to heart failure or femoral fracture. Risk assessment for in-hospital PE, including medical history and diagnosis at admission, is preferred in hospitalized patients.