Low molecular weight heparin (enoxaparin) versus oral anticoagulant therapy (acenocoumarol) in the long-term treatment of deep venous thrombosis in the elderly: A randomized trial

This study aims to establish the relative effectiveness and safety of low m olecular weight heparin in elderly patients with venous thrombosis in order to find an alternative to oral anticoagulant therapy with less bleeding co mplications in the long-term treatment of deep venous thrombosis (DVT). One hundred consecutive elderly patients (>75 years old) with venographical ly demonstrated proximal DVT were included in a randomized trial. All patie nts were treated for ten days with adjusted doses of intravenous heparin. I nformed consent was obtained and on the right day, patients were randomly a llocated to receive acenocoumarol (INR 2.0-3.0) or subcutaneous enoxaparin (4000 anti-Xa units once a day) for three months. All patients were followe d-up clinically and venographically for a one year period. The results were analyzed with Fisher's exact test or chi-square test as appropriate. During the treatment and surveillance period, 6 of the 50 patients (12%) wh o received acenocoumarol and 8 of the 50 patients (16%) who received enoxap arin had new episodes of venous thromboembolism confirmed by objective test ing (p = 0.6; 95% CI for the difference: -19.5 to 11.5). Hemorrhagic compli cations occurred in six of the 50 patients (12%) who received acenocoumarol and in one (2%) of those on enoxaparin (p = 0.1; 95% CI for the difference : -1.8 to 21.8). Vertebral fractures developed in 2 patients (4%) in the en oxaparin group (p = 0.5; 95% CI for the diference: -11.4 to 3.4). These results show that fixed dose enoxaparin seems to be effective and saf e in the long-term treatment of proximal DVT in the elderly. In comparison with oral anticoagulants, the findings are inconclusive due to the wide con fidence intervals for differences between outcomes, however they suggest th at the former may have less bleeding complications with similar efficacy.