Association between risk stratification for pulmonary embolism and deep vein thrombosis of lower extremities

Background The association of clinical risk factors, in particular deep vein thrombosis (DVT), with risk stratification for pulmonary embolism (PE) remains to be identified. We therefore aimed to establish the relationship between risk stratification of PE patients and DVT of lower extremities. Methods In this retrospective study, 93 out of 485 PE patients with uncompleted clinical data were excluded, resulting in 392 patients included for analysis. Based on the ESC criteria, 24, 171, and 197 patients were categorized into high (6.1%), intermediate (43.6%), and low risk (50.3%) subgroups, respectively. Results DVT was detected in 304 patients (77.6%). The incidence of DVT in patients with high and intermediate risk PE was much lower than in those patients with low risk PE (67.2% vs 87.8%,P< .0001). Further analyses of the 304 patients with DVT showed higher incidence of high and intermediate risk PE in patients with isolated distal DVT than proximal DVT (59.0% vs 39.1%,P= .005), with asymptomatic DVT than symptomatic DVT (63.0% vs 36.8%,P< .0001), and with bilateral DVT than unilateral DVT (54.5% vs 39.9%,P= .03). Stepwise logistic regression showed that symptomatic or asymptomatic DVT was an independent risk factor for risk stratification of PE patients with DVT (0.320, 95% confidence interval, 0.186-0.550). Conclusions Patients with high and intermediate risk PE presented lower incidence of DVT compared with patients with low risk PE. In PE patients with comorbid DVT, asymptomatic DVT is an independent risk factor for high and intermediate risk of PE.