SUBCUTANEOUS LOW-MOLECULAR-WEIGHT HEPARIN COMPARED WITH CONTINUOUS INTRAVENOUS HEPARIN IN THE TREATMENT OF PROXIMAL-VEIN THROMBOSIS

UNIV COLORADO HOSP DENVER CO 00000 PENROSE COMMUNITY HOSP COLORADO SPR INGS CO 00000 MERCY HOSP & MED CTR SAN DIEGO CA 92103 JEFFERSON MED CT R PHILADELPHIA PA 00000 Background. Low-molecular-weight heparin has a high bioavailability and a prolonged half-life in comparison with con ventional unfractionated heparin. Limited data are available for low-m olecular-weight heparin as compared with unfractionated heparin for th e treatment of deep-vein thrombosis. Methods. In a multicenter, double -blind clinical trial, we compared fixed-dose subcutaneous low-molecul ar-weight heparin given once daily with adjusted-dose intravenous hepa rin given by continuous infusion for the initial treatment of patients with proximal-vein thrombosis, using objective documentation of clini cal outcomes. Results. Six of 213 patients who received low-molecular- weight heparin (2.8 percent) and 15 of 219 patients who received intra venous heparin (6.9 percent) had new episodes of venous thromboembolis m (P = 0.07; 95 percent confidence interval for the difference, 0.02 p ercent to 8.1 percent). Major bleeding associated with initial therapy occurred in 1 patient receiving low-molecular-weight heparin (0.5 per cent) and in 11 patients receiving intravenous heparin (5.0 percent), a reduction in risk of 91 percent (P = 0.006). This apparent protectio n against major bleeding was lost during long-term therapy. Minor hemo rrhagic complications were infrequent. Ten patients receiving low-mole cular-weight heparin (4.7 percent) died, as compared with 21 patients receiving intravenous heparin (9.6 percent), a risk reduction of 51 pe rcent (P = 0.049). Conclusions. Low-molecular-weight heparin is at lea st as effective and as safe as classic intravenous heparin therapy und er the conditions of this study and more convenient to administer. The simplified therapy provided by low-molecular-weight heparin may allow patients with uncomplicated proximal deep-vein thrombosis to be cared for in an outpatient setting.