980-88 Free Floating Thrombus and Embolic Risk in Patients with Angiographlcally established Proximal Deep Venous Thrombosis. A Prospective Study

Abstract

Free floating thrombus (FFT) is generally considered as a high risk factor of pulmonary embolism (PE) in patients with lower limb proximal deep venous thrombosis (prox.DVT). 95 in-hospital patients with angiographically established recent prox.DVT were prospectively evaluated according to the presence (Group A) or the absence (Group B) of a FFT. On day 1, venous duplex scanning (VDS). perfusion lung scan (PLS) and pulmonary angiogram (PA), if abnormal PLS, were performed. On day 10 ± 1, PLS was repeated and PA, if impairment of PLS. A 3 month clinical follow-up was scheduled. Patients were treated with APTT adjusted iv unfractionated heparin (n = 2) or sc low molecular weight heparin (n = 93) (Nadroparin 225 Axa IC units/kg/12 H). Warfarin was initiated on day 3 ± 1.5 patients were excluded at baseline for uncertain phlebographic diagnosis of FFT. Group A (n = 62) and Group B (n = 28) were well matched according to age, sex, risk factors and delay from onset of symptoms to treatment. Sensitivity and specificity of VDS for the diagnosis of FFT were respectively 68 and 86%. On admission, PE prevalence was 65% in Group A(40/62) and 50% in Group B(14/28) (ns). 2 patients were excluded of the day 10 ± 1 follow-up analysis for preventive vena cava filtering (1 major bleeding, 1 cholecystectomy): recurrent PE rate was 3.3% in Group A (2/61) and 3.7% in Group B (1/27). No symptomatic recurrent PE occurred between day 10 ± 1 and 3 month. 4 patients died after hospital discharge (no death directly related to thromboembolic disease). Thus no higher risk of PE can be seen in patients with free floating prox-DVT and anticoagulant therapy should be efficient to prevent recurrent PE in such patients.