Comparison of Clinical and Imaging Characteristics and Outcomes between Provoked and Unprovoked Acute Pulmonary Embolism in Koreans

This study was performed to compare clinical and imaging parameters and prognosis of unprovoked pulmonary embolism (PE), provoked PE with reversible risk factors (provoked-rRF), and provoked PE with irreversible risk factors (provoked-iRF) in Koreans. Three hundred consecutive patients (mean age, 63.6 ± 15.0 yr; 42.8% male) diagnosed with acute PE were included. The patients were classified into 3 groups; unprovoked PE, provoked-rRF, and provoked-iRF; 43.7%, 14.7%, and 41.7%, respectively. We followed up the patients for 25.4 ± 33.7 months. Composite endpoint was all-cause mortality and recurrent PE. The provoked-iRF group had significantly higher all-cause mortality, mortality from PE and recurrent PE than the unprovoked and provoked-rRF groups (P < 0.001, P < 0.001, and P = 0.034, respectively). Prognostic factors of composite endpoint in the unprovoked group were high creatinine (> 1.2 mg/dL; P < 0.001; hazard ratio [HR], 4.735; 95% confidence interval [CI], 1.845-12.152), C-reactive protein (CRP; > 5 mg/L; P = 0.002; HR, 5.308; 95% CI, 1.824-15.447) and computed tomography (CT) obstruction index (P = 0.034; HR, 1.090; 95% CI, 1.006-1.181). In conclusion, provoked-iRF has a poorer prognosis than unprovoked PE and provoked-rRF. Renal insufficiency, high CRP, and CT obstruction index are poor prognostic factors in unprovoked PE.