Randomized comparison of enoxaparin with unfractionated heparin for the prevention of venous thromboembolism in medical patients with heart failure or severe respiratory disease

Background We compared the efficacy and safety of the low-molecular weight heparin enoxaparin with unfractionated heparin (UFH) for the prevention of venous thromboembolic disease in patients with heart failure or severe respiratory disease. Methods This was a multicenter, controlled, randomized, open study in which patients received either enoxaparin (40 mg once daily) or UFH (5000 IU 3 times daily) for 10 ± 2 days in 64 medical departments in Germany. Patients were stratified and enrolled according to their underlying disease: severe respiratory disease or heart failure. The primary efficacy parameter was a thromboembolic event up to 1 day after the treatment period. Results Of the 665 patients enrolled, 451 patients were able to be evaluated in the primary efficacy analysis. The incidence of thromboembolic events was 8.4% with enoxaparin and 10.4% with UFH. Enoxaparin was at least as effective as UFH, with a 1-sided equivalence region of −4% (90% CI −2.5-6.5, P = .015). Enoxaparin was associated with fewer deaths, less bleeding, and significantly fewer adverse events (45.8% vs 53.8%, P = .044). Conclusions Enoxaparin is at least as effective as UFH in the prevention of thromboembolic events in patients with heart failure or severe respiratory disease. Its beneficial safety profile and once-daily administration is advantageous for inpatient and outpatient use. (Am Heart J 2003;145:614-21.)