[Role of low molecular weight heparins for treating non-massive pulmonary embolism]

Pulmonary revascularization after submassive pulmonary embolism can be achieved within 14 days in 50% of the patients treated with intravenous heparin then oral anticoagulants. Recurrence is estimated at 5% and risk of severe haemorrhage at 5 to 6%. For deep vein thrombosis, low-molecular weight heparins are at least as effective as unfractionated heparin and have a comparable or lower rate of complications. For submassive pulmonary embolism, two low-molecular weight heparins (calcium nadroparin and sodium dalteparin) have been compared with unfractionated heparin. Pulmonary revascularization on day 8 was about 68% for all treatment regimens. No cases of recurrent embolism were recorded and no severe haemorrhage occurred in patients given low-molecular weight heparin but did occur in 6% of those given unfractionated heparin. These early results, together with easy subcutaneous administration and the absence of daily dose adaptation requirement, suggest that low-molecular weight heparins could play a major role in treating submassive pulmonary embolism and thromboembolism in general.