Malignant tumor is the greatest risk factor for pulmonary embolism in hospitalized patients: a single-center study

BACKGROUND: This study aimed to investigate the background of patients who presented with pulmonary embolism (PE) on contrast-enhanced chest computed tomography (CT) and to explore the risk factors for PE. METHODS: This study included a review of the medical records of all 50,621 patients who were admitted to one community hospital between January 1, 2013 and December 31, 2017. Data on sex, age, risk factors related to blood flow stagnation (obesity, long-term bed rest, cardiopulmonary disease, cast fixation, long-term sitting), risk factors related to vascular endothelial disorder (surgery, trauma/fracture, central venous catheterization, catheter tests/treatments, vasculitis, antiphospholipid antibody syndrome, history of venous thromboembolism (VTE)), and risk factors related to hypercoagulability (malignant tumor, use of oral contraceptives/low-dose estrogen progestin/steroids, infection, inflammatory enteric disease, polycythemia, protein C or protein S deficiency, dehydration) were evaluated. RESULTS: Of all inpatients, 179(0.35%) out of 50,621 were diagnosed with PE after contrast-enhanced chest CT examination, in which 74 patients were symptomatic and 105 patients had no symptom. Among asymptomatic 105 patients, 71 patients got CT scans for other reasons including cancer screening and searching infection focus, and 34 patients got CT scans for searching PE due to either apparent or suspicious DVT. The rate of discovering PE was significantly greater in women (0.46%, 90/19,409) than men (0.29%, 89/31,212) (P = 0.008). Of the 179 patients with PE, 164 (92%) had some type of risk factor. For both men and women, the most frequent risk factor was a malignant tumor, followed by obesity, long-term bed rest and infection for men and long-term bed rest, obesity and infection for women. The most common malignant tumor was lung cancer. Although taking antipsychotic agent is not advocated as a risk factor, there is a possibility of involvement. CONCLUSIONS: The risk factors for PE were identified in this single-center, retrospective study.