Low-molecular-weight heparin for the treatment of acute pulmonary thromboembolism. Comparison with unfractionated intravenous heparin

Low-molecular-weight heparins have been demonstrated at least as useful as unfractionated heparin (UFH) in the treatment of venous thromboembolic disease. Our aim was to know the effectivity and security of subcutaneous enoxaparin in the treatment of acute pulmonary embolism. We compared the effectivity and security of two doses daily, subcutaneous injected enoxaparin adjusted to body weight, and standard treatment with continuous intravenous UFH, determining the rate of major bleeding, in-hospital death and recurrent venous thromboembolic disease in long-term follow up. Massive pulmonary thromboembolism was defined as thrombotic material seen in main pulmonary arteries. Thirty eight patients were treated with UFH (Mean age 72 SD 9 years, male 58%, massive pulmonary thromboembolism 24%) and 65 patients were treated with subcutaneous enoxaparin (Mean age 71 SD 12 years, male 52%, massive pulmonary thromboembolism 49%). Major bleeding rate was 8% in UHF group and 3% in enoxaparin group (Difference 37%, 95% Confidence interval -0.16 to 0.06, p=0.21). In-hospital death rate was 8% in UHF group and 1.5% in enoxaparin group (Difference 25%, 95% Confidence interval -0.17 to 0.04, p=0.11). Recurrent thromboembolism rate was 44% in UFH group and 13% in enoxaparin group (Difference 30%, 95% Confidence interval -0.60 to -0.02, p=0.01). Our findings demonstrate that treatment of acute pulmonary thromboembolism with low-molecular-heparin is effective and safe, even in massive pulmonary embolism.