Low molecular weight heparin versus acenocoumarol in the secondary prophylaxis of deep vein thrombosis

The aim of this study was to determine the efficacy and safety of subcutane ous weight-adjusted dose low molecular weight heparin (LMWH) compared with Oral anticoagulant (OA) in the prevention of recurrent venous thromboemboli sm, rn a prospective multicenter trial, 202 patients with symptomatic proxi mal deep vein thrombosis (DVT) were included. As soon as the diagnosis of D VT was confirmed by phlebography, 101 were randomly assigned to receive LMW H (nadroparin) for secondary prophylaxis and 101 to receive OA (acenocoumar ol). Patients in both groups were initially treated with nadroparin in a do se of 85 anti-Xa IU/kg s.c. every 12 h. Secondary prophylaxis with either n adroparin, 85 anti-Xa IU/kg s.c. once daily, or acenocoumarol was continued for at least 3 months. Three patients in the LMWH group and 6 in the OA gr oup were excluded from analysis for various reasons. During the one-year co mbined secondary prophylaxis and surveillance period, 7 of of the 98 evalua ble patients (7.1%;) in the LMWH group and 9 of the 95 evaluable patients ( 9.5%) in the OA group had a documented recurrence of venous thromboembolism (Fisher's exact test, p = 0.61). Of these, 7 patients who received LMWH an d 7 patients on acenocoumarol had recurrences in the 3-month period of seco ndary prophylaxis. Four patients (4.1%) in the LMWH group developed bleedin g complications during this study period, as compared with 7 (7.4%) in the OA group (Fisher's exact test, p = 0.37). There were two major bleedings, o ne in the LMWH group and one in the OA group. Eleven patients died, 5 (5.1% ) in the LMWH group and 6 (6.3%) in the OA group. It is concluded that nadr oparin in a dose of 85 anti-Xa IU/kg s.c. once daily provides an effective and safe alternative to oral anticoagulants in the secondary prophylaxis of DVT.