Risk Factors Associated with Symptomatic Pulmonary Embolism of Catheter Directed Thrombolysis for Lower Extremity Deep Venous Thrombosis

ObjectiveThe aim was to study the risk factors associated with symptomatic pulmonary embolism (PE) in patients with deep venous thrombosis (DVT) in the lower limbs treated by catheter directed thrombolysis (CDT) without inferior vena cava filter (IVCF) placement.MethodsA total 266 patients with acute/subacute ilio-femoral, ilio-femoropopliteal, and femoropopliteal thrombosis confirmed by computed tomography venography or ultrasound Doppler were studied. All patients were treated with CDT. CTPA (computed tomography pulmonary angiography) examination was performed in all patients before thrombolysis. Patients with clinically suspected symptomatic PE were confirmed by repeated CTPA after treatment. The major outcome of this study was the occurrence of symptomatic PE events during CDT.ResultsDuring CDT, the incidence of symptomatic PE events was 4.9% (13/266). Patients with silent PE had a higher risk of developing symptomatic PE (10/110, 9.1%) than those who had no prior PE (3/156, 1.9%); multivariate analysis confirmed this difference (OR 4.018, 95% CI 1.048–15.402). It was also found that patients with previous heart disease had a higher risk of developing symptomatic PE (11/90, 12.2%) than those with no prior heart disease (2/176, 1.1%). Multivariate analysis confirmed that previous heart disease increased the risk of developing symptomatic PE (OR 10.407, 95% CI 2.228–48.617). One patient who suffered from heart failure and silent PE before CDT died of symptomatic PE (1/13, 7.7%).ConclusionThe risk of developing symptomatic PE is most markedly increased in patients with previous silent PE and heart disease. Selective rather than routine IVCF placement is an appropriate approach.