Prospective randomized controlled trial on the effect of fondaparinux sodium for prevention of venous thromboembolism after hip fracture surgery.
ABSTRACT Hip fracture surgery (HFS) carries a high risk of venous thromboembolism (VTE) in the absence of thromboprophylactic treatment. Previous reports have suggested that fondaparinux sodium (FPX) administration decreases the incidence of VTE after HFS and total hip and knee arthroplasties. However, investigations of that effect in Japanese populations remain inadequate. We evaluated the efficacy of FPX after HFS in a prospective randomized controlled trial.
Subjects comprised 76 consecutive Japanese patients who underwent HFS and were randomly assigned to the FPX group, who received subcutaneous injections of FPX 2.5 mg/day for 14 days beginning the next after HFS, or the control group (non-FPX group). D-dimer values were measured on admission and 7 and 14 days after HFS. Subjects with D-dimer levels over the cutoff value (> 20 microg/ml on day 7) underwent enhanced computed tomography (CT) to evaluate the possibility of deep vein thrombosis (DVT) of the lower extremities. D-dimer values, the incidence of DVT, and side effects associated with a bleeding tendency (i.e., hematoma or massive bleeding) were compared between groups.
The FPX group showed significantly lower D-dimer levels than the non-FPX group at 7 and 14 days after HFS (P < 0.05). Only one case in the FPX group exceeded the D-dimer cutoff compared to 12 cases in the non-FPX group (P = 0.001). DVTs were found with enhanced CT in one case in the FPX group and in five cases in the non-FPX group. In the FPX group, symptomatic hematoma at the surgical site and/or decreased hemoglobin > 2 g/dl was noted in four cases (10.5%). Postoperative drainage volumes did not differ significantly between groups.
FPX administration demonstrated positive effects on the prevention of VTE after HFS. However, careful postoperative observation is warranted to prevent serious side effects after FPX administration.
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ABSTRACT: Both prophylaxis and treatment of venous thromboembolism (VTE: deep venous thrombosis (DVT) and pulmonary emboli (PE)) with anticoagulants are associated with significant risks of major and fatal hemorrhage. Anticoagulation treatment of VTE has been the standard of care in the USA since before 1962 when the U.S. Food and Drug Administration began requiring randomized controlled clinical trials (RCTs) showing efficacy, so efficacy trials were never required for FDA approval. In clinical trials of 'high VTE risk' surgical patients before the 1980s, anticoagulant prophylaxis was clearly beneficial (fatal pulmonary emboli (FPE) without anticoagulants = 0.99%, FPE with anticoagulants = 0.31%). However, observational studies and RCTs of 'high VTE risk' surgical patients from the 1980s until 2010 show that FPE deaths without anticoagulants are about one-fourth the rate that occurs during prophylaxis with anticoagulants (FPE without anticoagulants = 0.023%, FPE while receiving anticoagulant prophylaxis = 0.10%). Additionally, an FPE rate of about 0.012% (35/28,400) in patients receiving prophylactic anticoagulants can be attributed to 'rebound hypercoagulation' in the two months after stopping anticoagulants. Alternatives to anticoagulant prophylaxis should be explored. The literature concerning dietary influences on VTE incidence was reviewed. Hypotheses concerning the etiology of VTE were critiqued in relationship to the rationale for dietary versus anticoagulant approaches to prophylaxis and treatment.Epidemiological evidence suggests that a diet with ample fruits and vegetables and little meat may substantially reduce the risk of VTE; vegetarian, vegan, or Mediterranean diets favorably affect serum markers of hemostasis and inflammation. The valve cusp hypoxia hypothesis of DVT/VTE etiology is consistent with the development of VTE being affected directly or indirectly by diet. However, it is less consistent with the rationale of using anticoagulants as VTE prophylaxis. For both prophylaxis and treatment of VTE, we propose RCTs comparing standard anticoagulation with low VTE risk diets, and we discuss the statistical considerations for an example of such a trial. Because of (a) the risks of biochemical anticoagulation as anti-VTE prophylaxis or treatment, (b) the lack of placebo-controlled efficacy data supporting anticoagulant treatment of VTE, (c) dramatically reduced hospital-acquired FPE incidence in surgical patients without anticoagulant prophylaxis from 1980 - 2010 relative to the 1960s and 1970s, and (d) evidence that VTE incidence and outcomes may be influenced by diet, randomized controlled non-inferiority clinical trials are proposed to compare standard anticoagulant treatment with potentially low VTE risk diets. We call upon the U. S. National Institutes of Health and the U.K. National Institute for Health and Clinical Excellence to design and fund those trials.Theoretical Biology and Medical Modelling 01/2010; 7:31. · 1.86 Impact Factor