Factors associating with the presence of residual thrombosis after 3-month treatment of acute pulmonary embolism

The present study aimed to investigate the factors associating with the presence of residual thrombosis in patients with acute pulmonary embolism (APE) after at least 3-month anticoagulant therapy. Demographic and clinical data of 180 cases in the affiliated hospital of Qingdao University from January 2005 to June 2015 were retrospectively analyzed. APE in all patients were confirmed by computed tomography pulmonary angiography (CTPA). Patients were then detected for the presence of residual thrombosis according to a second CTPA. After appropriate comparison test, multivariate logistic regression analysis was performed to identify predictors for residual thrombosis. Among 180 patients, complete clearance of thrombosis occurred in 115 (63.9%) patients. Residual thrombosis remained in 65 (36.1%) patients. The independent factors associating with residual thrombosis include unprovoked APE (OR 0.231, 95% CI 0.062–0.861) and fibrinogen level in acute phase (OR 1.958, 95% CI 1.282–2.911). Furthermore, these two variables were both associated with the presence of residual thrombosis in patients receiving different parenteral anticoagulants (unfractionated heparin or low-molecular-weight heparin). Pulmonary thrombosis in some patients with APE are not completely dissolved after at least 3-month treatment. Additionally, unprovoked APE is positive predictor of decreased residual thrombosis and fibrinogen level in acute phase is a risk factor of the presence of residual thrombosis.