Acute deep vein thrombosis: A prospective registry of 5451 patients

Abstract number: P1470

Goldhaber^* S. Z., Tapson† V. F.

^*Brigham and Women's Hospital, USA; †Duke University Medical School, USA

To improve our understanding of the history, prior prophylaxis, and treatment of patients with newly diagnosed acute deep venous thrombosis (DVT), we undertook a large-scale, prospective registry of 5451 patients from 183 study sites in the United States between October 2001 and April 2002. In all patients, the diagnosis of DVT was confirmed by venous ultrasound examination. There were no exclusion criteria. We enrolled 2892 women and 2559 men, with a mean age of 64 years and a mean body mass index of 28.4 kg m^-1 squared. Of the 5451 patients, 2725 were diagnosed as outpatients or in the emergency department and 2726, as inpatients. In 18% (n = 793) of patients, concomitant pulmonary embolism (PE) was confirmed by imaging studies. For outpatients, the median time to diagnosis was 3 days after symptoms began, whereas for inpatients, it was 1 day. The median duration of hospitalization was 5 days for those diagnosed as outpatients, as opposed to 12 days for those diagnosed as inpatients. Low-molecular-weight heparin was used as a ‘bridge’ to warfarin in 2143 patients, and continuous intravenous unfractionated heparin was used for the same purpose in 1926 patients. Symptoms or signs of DVT or PE were reported by 4907 patients. The most commonly reported symptoms included swelling (70%), extremity discomfort (53%), dyspnea (18%), erythema (13%), and difficulty in walking (10%). Of patients with newly diagnosed DVT, 1557 (29%) received prophylaxis within 30 days prior to the diagnosis of DVT, including 449 with unfractionated heparin and 241 with low-molecular-weight heparin. DVT FREE documents a discrepancy between current treatment guidelines and clinical practice. Despite the American College of Chest Physicians' endorsement of outpatient therapy with low-molecular-weight heparin for acute DVT, a surprisingly low proportion of patients receive this therapy. This finding suggests that the efficacy and cost-effectiveness of low-molecular-weight heparin compared with intravenous unfractionated heparin may not be generally appreciated. In addition, routine preventive efforts among inpatients are not widely practiced, especially among acutely ill patients with medical illnesses. DVT FREE provides a real-life profile of patients diagnosed with DVT throughout the United States. These findings indicate that clinical trials and guidelines for DVT have progressed further and faster than ‘real world’ preventive efforts and outpatient therapy.