A comparison of survival rates at 8–10 years for hip-fracture patients given thromboprophylaxis with enoxaparin vs. unfractionated heparin

Abstract number: P1400

Borris^* L. C., Lassen† M. R., Breindahl† M., Jensen‡ H. P.

^*Århus University Hospital, Denmark; ‡Aalborg University Hospital, Denmark †Copenhagen University Hospital, Denmark;

Background  

Hip fracture is common in elderly patients and is a significant risk factor the development of venous thromboembolism (VTE). We report here the long-term (8–10 years) follow up of a clinical study conducted between 1992 and 1994 of 331 patients with acute hip fracture.

Methods  

Patients were randomly assigned thromboprophylaxis with either enoxaparin 40 mg once daily (N = 167) or unfractionated heparin (UFH) 5000 IU twice daily (N = 164), injected subcutaneously for 7 ±2 days. Mandatory bilateral venography was performed 7–10 days after inclusion to diagnose deep-vein thrombosis in the legs. Autopsy was performed in case of death whenever possible. Patients were followed up at 8–10 years to determine the total rate of death, and death profiles in the groups using the Kaplan-Meier method.

Results  

The two groups were comparable in terms of demographic characteristics, type of fracture, anesthesia and surgical treatment. Average age was 77.1 years in the enoxaparin group and 75.5 years in the UFH group. No significant differences were detected between the two regimens with regard to occurrence of VTE or bleeding complications at 3 months. In total, 215 patients died during the 8–10 years follow-up period. Kaplan-Meier analysis revealed significantly better survival in the enoxaparin group compared with the UFH group at 3, 6 and 9 months and a trend towards better survival up to approximately 50 months, after which no differences were observed between treatments.

Discussion  

The survival of patients receiving acute thromboprophylaxis with enoxaparin was significantly better during the first 9 months, with a trend toward better survival persisting until 50 months when compared with those receiving UFH. As the average patient age was over 75 years at study start, and many could be expected to die from unrelated illness, the reasons for death during the follow up period will be analyzed and presented.