Thursday, October 24, 2013

IS WARFARIN DEAD FOR THE PREVENTION OF STROKES IN ATRIAL FIBRILLATION?

This topic was the subject of a debate at the recent Canadian Cardiovascular Congress 2013, in Montreal. The protagonist is Dr Paul Dorian of the U of Toronto, Ontario, and the antagonist is Dr Brent Mitchell of U of Calgary, Alberta. Note that one is from affluence Ontario and the other, from less affluent Alberta.


Of course they both reviewed the trials and spoke eloquently. Dr Dorian's main argument seems to be that it was more convenient to take dabigatran as the patient does not have to monitor PT INR, and assumes that 2 tabs a day routinely, is enough. Should stroke occur, it is just too bad. The patient does not have to bother about food interactions and of course, the problem with warfarin is if you push to achieve an INR of 3 of above 3. Then the incidence of bleeding becomes almost 15-20 % in the first 6 months of use. So Dr Dorian, who is a fashion conscious medical practitioner, said that just as first generation mobile phones are dead, so also Warfarin.
However Dr Mitchell argued well that warfarin still does a stella job in preventing strokes and that in his experience, the risk of bleeding with warfarin is not much more when compared to Dabigatran 110mg BiD. Thre is also no antidote to reverse the effects of dabigatran should bleeding occur. With warfarin, there is still the good old Vit K and factor transfusion.  However, I thought that the victory clinching argument was cost. In atrial fibrillation, you have to treat 1,429 patients ( RELY data ) to prevent one stroke or one thromboembolic event a year. On the average, dabigatran cost USD 3,000 a year more than warfarin, including INR monitoring. So dabigatran cost USD 4 Million a year , a patient, to prevent one stroke a year. Multiply that with the number of patients with atrial fibrillation, and you will see the impact of using dabigatran on a National Healthcare Budget. Money that could be more usefully spend on Dengue, Malaria, hypertension, diabetes and other healthcare problems. In Alberta, Dr Mitchell said that the insurance company would only allow the use of warfarin if the practitioner can show why warfarin should not be used.

Of course Dr Mitchell won the debate and was presented with a toy mouse.

There is a lesson here for Malaysian practitioners, who are fashionable doctors.

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