Extended venous thromboembolism prophylaxis after total hip replacement: a comparison of low-molecular-weight heparin with oral anticoagulant.
BACKGROUND
Oral anticoagulants and low-molecular-weight heparin are both recommended for venous thromboembolism prophylaxis after total hip replacement. To date, these regimens have not been compared by means of clinical end points in the extended prophylaxis setting.


METHODS
We randomly assigned 1279 patients 3 days after total hip replacement surgery to fixed-dose subcutaneous low-molecular-weight heparin (reviparin sodium, 4200 anti-Xa IU) or adjusted-dose oral anticoagulant (international normalized ratio, 2-3; acenocoumarol) for a 6-week period. The primary end point was the failure rate, defined as the combined clinical events of a confirmed symptomatic thromboembolic event, a major hemorrhage, or death. All patients were followed up throughout the study interval. The primary objective was to compare the observed cumulative failure rate in the low-molecular-weight heparin vs oral anticoagulant group.


RESULTS
In the intent-to-treat population, objectively documented symptomatic thromboembolic events occurred in 15 (2.3%) of 643 patients vs 21 (3.3%) of 636 patients receiving low-molecular-weight heparin or oral anticoagulants, respectively (P =.30; 95% confidence interval for the difference, -0.8% to 2.8%). Major bleeding occurred in 9 (1.4%) of 643 patients vs 35 (5.5%) of 636 patients receiving low-molecular-weight heparin or oral anticoagulants, respectively (P =.001). The failure rate was 24 (3.7%) of 643 patients compared with 53 (8.3%) of 636 patients who received low-molecular-weight heparin or oral anticoagulants (P =.001).


CONCLUSIONS
A significantly higher benefit-risk ratio was observed for patients undergoing elective hip replacement who received extended out-of-hospital prophylaxis with low-molecular-weight heparin vs acenocoumarol. Low-molecular-weight heparin prophylaxis was at least as effective as oral anticoagulants, but with a marked improvement in safety.
Samama
Charles Marc
CM
Département d'Anesthésie-Réanimation, Hôpital Avicenne-125, route de Stalingrad, 93009 Bobigny CEDEX, France. cmsamama@invivo.edu
Vray
Muriel
M
Barré
Jeanne
J
Fiessinger
Jean-Noël
JN
Rosencher
Nadia
N
Lecompte
Thomas
T
Potron
Gérard
G
Basile
Joseph
J
Hull
Russell
R
Desmichels
Denise
D
D000074:Acenocoumarol / Q000008:administration & dosage* / Q000009:adverse effects; D000284:Administration, Oral; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000209:etiology / Q000517:prevention & control
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D000074:Acenocoumarol