Author Interviews, BMJ, Clots - Coagulation, Heart Disease, Stroke / 06.02.2016
Is the Evidence for the Anticoagulant Rivaroxaban Valid?
MedicalResearch.com Interview with:
Dr. Deborah Cohen
Associate Editor BMJ
BMA House, Tavistock Square
London
Medical Research: What is the background for this study? What are the main findings?
Dr. Cohen: Anyone familiar with warfarin understands the critical role of INR values in determining the proper dose for warfarin patients. The INR value in an individual patient is the most important piece of information a doctor considers when determining the warfarin dose. If the doctor gives too little warfarin then the patient may be at undue risk of stroke; if too much, the patient may be at undue risk of a major bleed.
The BMJ investigation revealed that the INR device used to manage the ~7,000 warfarin patients in the ROCKET trial (which served as the basis for approval of the non-valvular atrial fibrillation indication) was defective.
As such – doctors were relying upon a defective device in determining the dose of the warfarin patients – which has a direct influence on the stroke and bleeding risk in that patient. Since this was a comparative trial – any deficiency in the performance of the comparator arm (warfarin) would skew the results in favour of the study drug (rivaroxaban).
Since INR directly influences strokes and bleeds – the primary efficacy and safety endpoints – it very much questions, if not undermines, the overall results of this trial.
(more…)