RESUMEN
OBJECTIVES: To compare the efficacy and safety of the low molecular weight heparin (LMWH) dalteparin with unfractionated heparin (UFH) in the acute treatment of DVT patients who had not previously received UFH. DESIGN: An open randomized multicentre trial with blinded analysis of venograms. SETTING: Seven hospitals in Sweden, Finland and the USA. SUBJECTS: A total of 330 patients, of 20 years or older, with suspected DVT, verified using venography. INTERVENTIONS: Fixed-dose dalteparin (200 IU kg-1) given as a once-daily subcutaneous injection, or aPTT adjusted i.v. UFH infusion for 6 to 10 days. MAIN OUTCOME MEASURES: Change in Marder score in patients with confirmed DVT and two evaluable venograms; PE, bleeding events and follow-up. RESULTS: Marder scores improved in 51% (95% CI 42-60%) of 92 patients treated with dalteparin and in 62% (95% CI 53-70%) of 98 patients treated with UFH (P = 0.152). One dalteparin-treated patient had a PE confirmed by V/Q scan; another had progressive thrombosis with swelling in the affected limb. Bleeding complications occurred in six patients in each group. One patient treated with dalteparin and five treated with UFH died during the 6-month follow-up period as a result of underlying malignancy or heart disease. The 6-month recurrence rate was low with both treatments (dalteparin, 3/97; UFH, 2/103). CONCLUSIONS: Fixed-dose subcutaneous dalteparin given once daily from the start of treatment is of equivalent efficacy and safety to conventional UFH therapy in the routine management of DVT.