Duration of prophylaxis against venous thromboembolism with fondaparinux after hip fracture surgery: a multicenter, randomized, placebo-controlled, double-blind study.
BACKGROUND
The benefit of thromboprophylaxis for 1 month has never been evaluated in patients undergoing hip fracture surgery, a setting in the highest risk category for postoperative venous thromboembolism (VTE).


METHODS
In a double-blind multicenter trial, 656 patients undergoing hip fracture surgery were randomly assigned to receive prophylaxis with a once-daily subcutaneous injection of either 2.5 mg of fondaparinux sodium or placebo for 19 to 23 days. Before randomization, all patients had received fondaparinux for 6 to 8 days. The primary efficacy outcome was VTE occurring during the double-blind period (deep vein thrombosis detected by mandatory bilateral venography or documented symptomatic deep vein thrombosis or pulmonary embolism). The main safety outcome was major bleeding.


RESULTS
The primary efficacy outcome was assessed in 428 patients. Fondaparinux reduced the incidence of VTE compared with placebo from 35.0% (77/220) to 1.4% (3/208), with a relative reduction in risk of 95.9% (95% confidence interval, 87.2%-99.7%; P<.001). Similarly, the incidence of symptomatic VTE was significantly lower with fondaparinux (1/326; 0.3%) than with placebo (9/330; 2.7%). The relative reduction in risk was 88.8% (P =.02). Although there was a trend toward more major bleeding in the fondaparinux group than in the placebo group (P =.06), there were no differences between the 2 groups in the incidence of clinically relevant bleeding (leading to death, reoperation, or critical organ bleeding).


CONCLUSIONS
Extended prophylaxis with fondaparinux for 3 weeks after hip fracture surgery reduced the risk of VTE by 96% and was well tolerated.
Eriksson
Bengt I
BI
Orthopedics Department, Sahlgrenska University Hospital/Ostra, Göteborg, Sweden. b.eriksson@orthop.gu.se
Lassen
Michael R
MR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D000077425:Fondaparinux; D006620:Hip Fractures / Q000601:surgery*; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D011134:Polysaccharides / Q000008:administration & dosage* / Q000009:adverse effects; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000209:etiology / Q000517:prevention & control*
D005343:Fibrinolytic Agents; D011134:Polysaccharides; D000077425:Fondaparinux