A total of 164 patients were recruited from a randomized trial comparing a low molecular weight heparin, dalteparin, given subcutaneously once daily with a continuous intravenous infusion of unfractionated heparin in the initial treatment of acute deep vein thrombosis. The primary objective of this follow-up study was to investigate whether there were any differences between the two treatment groups with respect to Marder score changes 6 months after the initial diagnosis using repeated venography. The secondary objectives were to analyse whether certain haemostatic and acute phase parameters or patient characteristics influenced the venographic outcome.
Results: Complete lysis of the thrombus was observed in 38.4% of the patients and a partial lysis in another 54.3% assessed by venography 6 months after the acute event. Extension of the thrombus was seen in 7.3% of the patients. There were no significant differences in the change in mean Marder score before treatment and at the 6 month follow-up between the two treatment groups, irrespective of thrombus localisation. In a regression model, male gender, low levels of orosomucoid and increased levels of d-dimer in plasma on day 5 were independently associated (p <0.05) with an enhanced absolute resolution of the thrombus at 6 months. No differences in symptoms and signs in the thrombotic leg at follow-up, comparing the treatment given, or thrombus extension at diagnosis and 6 months later, were demonstrated.
Conclusion: Dalteparin given once daily subcutaneously was as effective as continuous intravenous infusion of unfractionated heparin in the initial treatment of deep vein thrombosis assessed by Marder score evaluation 6 months after the acute event.