Germany: New data from two RE-LY® sub-group analyses has presented at the 60th Annual Scientific Session of the American College of Cardiology (ACC) demonstrated that dabigatran etexilate 150mg bid is consistently superior to warfarin in stroke prevention in atrial fibrillation (AF), irrespective of a patient’s risk of stroke or type of AF.1,2

RE-LY®, the largest AF trial to date, was a PROBE (prospective, randomised, open-label with blinded endpoint evaluation) trial designed to compare two fixed doses of the oral direct thrombin inhibitor dabigatran (110mg and 150mg bid) each administered in a blinded manner, with open label warfarin. Pradaxa® 110mg bid was shown to be as effective as warfarin.3,4

The sub-group analyses assessed the rate of stroke and systemic embolism with dabigatran etexilate compared to well-controlled warfarin in patients with different types of AF (paroxysmal, persistent, permanent) and according to a refined stroke risk score CHA2DS2VASc,5 which complements the traditionally used CHADS2 score6 and has been recommended in current European guidelines.5

The results showed:

The reduction of stroke rates seen with dabigatran etexilate 150mg bid compared to well-controlled warfarin across all CHA2DS2VASc stroke risk groups were consistent with the overall RE-LY® trial conclusions [as indicated by the p-value for interaction=0.60], which established the superiority of dabigatran etexilate 150mg bid versus well-controlled warfarin2

The CHA2DS2VASc data were consistent with results from a previous sub-group analysis using the CHADS2 score, which showed that dabigatran etexilate 150mg bid reduced the rate of stroke across all stroke risk groups, including the patients in the high risk group [n=5,882]7

Dabigatran etexilate 150mg and 110mg bid doses have a favourable benefit risk profile compared to warfarin, including in patients with lower CHA2DS2VASc scores2

Dabigatran etexilate 150mg bid offers improved efficacy versus well-controlled warfarin (median TTR = 67%)8 for the prevention of stroke irrespective of the type of AF (paroxysmal, persistent, permanent), consistent with the overall RE-LY® trial conclusions [as indicated by the p-value for interaction=0.16] 1

Dr Jonas Oldgren, Uppsala University Hospital, Sweden said, “Continuing on from previous RE-LY® sub-group analyses, these data provide further evidence supporting dabigatran etexilate as an attractive alternative for stroke prevention in non-valvular AF across a wide range of patients and with different types of AF (paroxysmal to permanent). The availability of two dose strengths of dabigatran etexilate provides the opportunity to facilitate careful attention of individual patient characteristics.”

The new CHA2DS2VASc risk score was recently incorporated into the revised 2010 European Society of Cardiology (ESC) guidelines and allows physicians to conduct a more detailed stroke risk assessment using a comprehensive risk factor-based approach. The ESC guidelines recommend antithrombotic therapy in all AF patients with at least one ‘clinically relevant non-major’ risk factor (CHA2DS2VASc score = 1), broadening the range of patients who should be treated with anticoagulants.5

Professor Gregory Lip, Professor of Cardiovascular Medicine at the University of Birmingham Centre for Cardiovascular Sciences, City Hospital Birmingham said, “Due to the limitations of warfarin, only about 50% of patients receive an appropriate treatment for stroke prevention in AF. Now novel oral anticoagulants are becoming available that are not limited by drug/ food interactions and the need for frequent monitoring. On that background, more sensitive stroke risk measures like the new CHA2DS2VASc score may improve access to and uptake of more effective treatments, which may ultimately reduce the number of strokes experienced by patients with AF. Any stroke risk factor in association with AF can cause a stroke, and if we are serious about preventing stroke, the most effective treatment is oral anticoagulation therapy.”