Home therapy with LMWH in deep vein thrombosis: randomized study comparing single and double daily administrations

The aim of this study was to assess the effectiveness of low-molecular-weight heparin (LMWH) treatment of deep vein thrombosis (DVT) in terms of the evolution of thrombosis, the incidence of adverse events, and compliance with heparin treatment using 2 types of LMWH available on the market administered in therapeutic doses throughout the period of treatment (Nadroparin) or at therapeutic doses only during the first month of treatment followed by a prophylactic phase at half dose (Parnaparin). A randomized prospective study was carried out on patients under observation with a recent diagnosis of DVT. The objectives of the study were to confirm the effectiveness of therapy with LMWH in terms of prevention of the risk of thromboembolism, of relapse of DVT, and of hemorrhagic complications, and to complete an evaluation of venous recanalization and residual valve competence in the 2 groups of patients. From December 2002 to June 2005, we randomized a total of 91 patients (51 in the Parnaparin group and 40 in the Nadroparin group). Overall, there was 1 case of nonfatal pulmonary embolism (1.1%) at 7 days into therapy with LMWH. There were 3 cases (3.3%) of progression of thrombosis despite therapy with LMWH, 2 cases (5%) in the Nadroparin group, and 1 case (2%) in the Parnaparin group (P = NS), and after suspension of the therapy, there was 1 case of relapse of thrombosis. Three of the 4 thrombotic events occurred in patients with active neoplasia. Moreover, only 1 major hemorrhagic event (1.1%) required blood transfusion. The Doppler ultrasound in the follow-up showed a complete resolution of 56% of the vein thromboses at an average of 6.1 +/- 4.6 (mean +/- SD) months. Valve competence recovered in 65.9% of cases with no significant difference between the 2 heparin groups. Home treatment of sural and femoral-popliteal DVT using LMWH represents a safe and effective method in the prevention of pulmonary embolism and encourages the process of recanalization of the thrombosed vessel, especially in cases of sural and/or popliteal DVT. Administration can be carried out with the same degree of safety at the therapeutic dose throughout the period of treatment or can be halved after the first month of treatment. In patients with active neoplasia, treatment with oral anticoagulant therapy must be considered.