Patients with right lower extremity deep vein thrombosis have a higher risk of symptomatic pulmonary embolism: a retrospective study of 1585 patients.

OBJECTIVE To determine the risk for pulmonary embolism (PE) and explore the relationship between the site of thrombosis and PE in patients with acute lower extremity deep vein thrombosis (DVT). METHODS 1585 hospitalized patients first diagnosed with acute lower extremity DVT were investigated retrospectively. The patients were divided into two groups: the non-PE group (Group 1) and the PE group (Group 2). Then, Group 2 was divided into two subgroups: asymptomatic pulmonary embolism (asPE, Group 2a) and symptomatic pulmonary embolism (sPE, Group 2b). Kaplan-Meier curves and logistic regression analysis were used to explore the relevant risk factors for PE. RESULTS Among 1585 patients, 458 patients suffered from PE, accounting for 28.9%. 102 (22.3%) of them had the typical clinical manifestations of PE and were defined as sPE, and the remaining 356 (77.7%) patients were classified as asPE. Patients with proximal lower extremity DVT were significantly more predominant in the PE group than in the non-PE group (92.8% vs. 86.2%, p<0.001). Moreover, in Group 2, patients with typical PE manifestations showed a higher proportion of patients with right lower extremity DVT than left lower extremity DVT (26.7% vs. 17.7%, P=0.035), and bilateral lower extremity DVT than unilateral DVT (44.1% vs. 20.5%, p<0.001). By multivariate analysis, alcohol consumption (OR, 1.824; 95% CI, 1.194-2.787; p=0.005), heart failure (OR, 2.345; 95% CI, 1.560-3.526; p<0.001), proximal DVT (OR, 2.096; 95% CI,1.407-3.123; p<0.001) were independent risk factors for PE. CONCLUSION Patients with proximal acute lower extremity DVT were more likely to suffer from PE than those with distal DVT. Patients with right acute lower extremity DVT had a higher risk of sPE than patients with left acute lower extremity DVT. Alcohol consumption and heart failure were associated with the occurrence of PE in patients with acute lower extremity DVT.