Treatment of deep venous thrombosis by fixed doses of a low-molecular-weight heparin (CY216).

Ninety consecutive outpatients with acute proximal and/or distal deep-vein thrombosis (DVT), as shown by phlebography, were entered into a prospective randomized trial comparing intravenous adjusted unfractionated heparin (UFH) with subcutaneous fixed doses of a low-molecular-weight heparin (CY216; 225 IC anti-Xa U/kg 12 hourly) for 10 days. The incidence of pulmonary embolism did not differ in the two groups (one episode per group). The comparison between pre- and posttreatment venograms and perfusion lung scans showed a statistically significant improvement (p less than 0.01 and p less than 0.05, respectively) only in the CY216-treated group. The incidence of major adverse reactions (major hemorrhages, relevant hemoglobin fall, and serious thrombocytopenia) was significantly higher (22 vs. 4.5%; p = 0.01) in the UFH-treated group. After a mean follow-up period of 2 years, the incidence of thromboembolic recurrences and that of post-thrombotic manifestations did not differ in the two groups. It is concluded that subcutaneous fixed doses of CY216 are more effective and safer than intravenous adjusted UFH in the treatment of acute DVT.