Oral dabigatran etexilate (DE) is as effective as enoxaparin in reducing risk of venous thromboembolism (VTE) after total hip replacement surgery. This is the conclusion of authors of an Article published in this week's edition of The Lancet.
Dr Bengt Eriksson, Sahlgrenska University Hospital, Gothenburg, Sweden, and colleagues did a double-blind study (the RE-NOVATE study) of 3494 patients undergoing total hip replacement, receiving treatment for 28-35 days, randomised to receive either oral DE 220mg once daily, DE150mg once daily, or a subcutaneous injection of enoxaparin 40mg once daily. The primary outcome of the treatment was judged by blood clot (venographic or symptomatic) and death from all causes during treatment.
For the patients on 220mg DE, this outcome occurred in 53 of 880 patients 6.0%); for 150mg DE, in 75 of 874 patients (8.6%); and in the enoxaparin group in 60 of 897 patients (6.7%). There was no significant difference in major bleeding rates with either DE dose compared with enoxaparin, nor in frequency of either acute coronary events or increases in liver enzyme concentrations.
The authors conclude: "Our results show that oral dabigatran etexilate, 220mg or 150mg once daily, given for a median of 33 days, was non-inferior to enoxaparin for reducing the risk of total venous thromboembolism, and all-cause mortality after total hip replacement surgery.
"These findings, in conjunction with other results from the large, phase III development programme in total hip and knee replacement surgery, will help define the optimum dosage regimen for dabigatran etexilate."
However an accompanying Comment warns of methodological flaws in the study due to missing data. Dr John Norrie, Centre for Healthcare Randomised Trials, University of Aberdeen, Scotland, UK says that VTE trials with venographically determined primary outcomes typically result in one in three patients not having data â€" either venography is not done or results are unreadable. He says: "The bottom line is that the effect of these missing data is unknown."
He concludes by calling for future VTE trials to be designed with safety analyses in mind, and says: "Even in a mature research area such as treatments for venous thromboembolism, there is still important methodological work to be done to improve design and so ensure the highest quality of evidence to inform the management of these conditions."
The paper can be accessed through the link below: