Prophylaxis in MEDical patients with ENOXaparin (1999)


Prophylaxis for VTE in acutely ill medical patients

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To evaluate the efficacy and safety of 2 dosage regimens of enoxaparin for the prevention of VTE in medical patients immobilized with severe illness

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Trial design

Randomized, double-blind, placebo-controlled study
Active treatment: enoxaparin 20 mg (n=364) or 40 mg (n=367) s.c. once daily for 6–14 days
Control treatment: placebo s.c. once daily for 6–14 days (n=371)

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Primary efficacy endpoint: DVT, PE, or both between days 1 and 14
Secondary efficacy endpoint: VTE between days 1 and 110
Safety endpoints: major and minor bleeding between days 1 and 14, overall mortality between days 1 and 110, and thrombocytopenia

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Trial participants

1102 general medical patients (mean age 73 years) whose projected stay in the hospital was at least 6 days, and who were immobilized for <3 days for acute medical disorders (heart failure NYHA class III or IV, respiratory failure, acute infection, rheumatic disorder, or active episode of inflammatory bowel disease); most of the patients had ≥2 risk factors for VTE

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Efficacy outcome: 866 patients were included in the analysis. The incidence of VTE by day 14 was 15.0% (43 of 287) in patients receiving enoxaparin 20 mg, 5.5% (16 of 291) in those receiving enoxaparin 40 mg, and 14.9% (43 of 288) in those assigned to placebo. The difference observed between enoxaparin 40 mg and placebo was statistically significant (p<0.001; relative risk reduction 63%). The incidence of any DVT or of proximal or distal DVT was significantly lower among patients in the 40-mg group than among those given placebo; the risk reduction for proximal DVT was 65%. The benefit observed with enoxaparin was maintained during the 3-months followup period. By 110 days, the incidence of VTE was 17.5%, 7.0%, and 17.1%, respectively (p<0.001 for enoxaparin 40 mg vs. placebo). There were no significant differences in primary outcome between the 20-mg group and the placebo group
Safety outcome: 1073 patients were included in the analysis of safety. During the treatment period, major hemorrhage occurred in 1 of 351 patients assigned to enoxaparin 20 mg (0.3%), 6 of 360 patients receiving enoxaparin 40 mg (1.7%), and 4 of 362 patients of the placebo group (1.1%). The rates for minor bleeding complications were 11.4%, 10.8%, and 7.5%, respectively. The incidence of thrombocytopenia was not different between treatment groups. At 110 days, 142 patients had died: 50 in the placebo group (13.9%), 51 in the 20-mg group (14.7%), and 41 in the 40-mg group (11.4%)

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Efficacy: Enoxaparin 40 mg reduced significantly the risk of VTE in acutely ill medical patients during hospitalization. This benefit was maintained during 3-month follow-up
Safety: Bleeding complications and other adverse events did not significantly differ between the placebo group and either enoxaparin group

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Samama MM, Cohen AT, Darmon JY, Desjardins L, Eldor A, Janbon C, Leizorovicz A, Nguyen H, Olsson CG, Turpie AG, Weisslinger N. A comparison of enoxaparin with placebo for the prevention of venous thromboembolism in acutely ill medical patients. N Engl J Med 1999;341:793–800

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Corresponding author

Meyer Michel Samama, MD, Département d’Hématologie Biologique, Hôtel Dieu, 1 Pl. du Parvis Notre Dame, 75181 Paris CEDEX 04, France

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