References for this review were identified by searches of PubMed using the search terms “atrial fibrillation”, “stroke”, and “prevention”. Other references were identifed from relevant articles and through searches of the authors' files.
Rapid ReviewWarfarin for atrial fibrillation: the end of an era?
Section snippets
Current prevention strategies
Although warfarin was introduced into clinical practice during the 1950s, it was not until the late 1980s that level I evidence was provided for its effectiveness in primary and secondary prevention of stroke for patients with non-valvular AF.2, 8, 9 In a recent meta-anlaysis of five primary prevention trials, adjusted dose warfarin was shown to reduce fatal and non-fatal stroke by 62% (95% CI 48–72) with an absolute risk reduction of 2·7% per year.2 Even greater benefits exist for the
Problems with current treatment
There are two major problems associated with the use of warfarin. First, the therapeutic window is very small so that the level of anticoagulation needs to be monitored frequent. The optimal international normalised ratio (INR) for stroke prevention is 2·0–3·0.17 For INR values of 1·7 and 1·5 stroke risk is double or triple, respectively, that for INR 2·0–3·0; INR greater than 3·0 is associated with a higher risk of haemorrhage. Overall, if 1000 patients with non-valvular AF are treated with
New approaches to stroke prevention
After half a century of ad-hoc use of warfarin in non-valvular AF and a decade of its use on the basis of level I evidence (but gross under-use in actual clinical practice), there are, at last, genuine alternative strategies that are in various stages of development. Therapeutic alternatives to warfarin are the nearest to entering clinical practice (table 2) but several interventional and surgical procedures are also being assessed.
Conclusions
Although warfarin is effective in stroke prevention for patients with AF, there are limitations to its use—bleeding side-effects, the need for monitoring, a narrow therapeutic window, etc. Given that AF is such an important risk factor for stroke, particularly in elderly people, the development of oral drugs, such as ximelagatran, that are as safe—should the raised liver enzyme issue be resolved—and effective as warfarin but do not require anticoagulant monitoring is a significant advance. The
Search strategy and selection criteria
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Cited by (35)
Antithrombotic drugs in the prevention of ischemic stroke
2006, Journal de Readaptation MedicaleControversies in atrial fibrillation
2006, LancetCitation Excerpt :These compounds bind tightly to antithrombin, have a long half-life, and produce predictable anticoagulation without monitoring. Idrapariunux is presently being compared with vitamin-K-antagonist treatment in more than 7000 patients with atrial fibrillation and stroke-risk factors in the AMADEUS trial.91 This arm of the trial was stopped prematurely because of the obvious benefit of warfarin over antiplatelet therapy.
Antithrombotic drugs in the prevention of ischemic stroke
2005, Journal des Maladies VasculairesFuture directions: American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery
2005, ChestCitation Excerpt :Studies (AMADEUS) are ongoing to see whether these agents are suitable alternatives to warfarin. They still require a subcutaneous injection.28 Unfortunately, measuring efficacy is difficult, and if bleeding occurs, reversal treatment may be more difficult in patients receiving these drugs than in patients receiving heparin or warfarin.29
Arrhythmias and cardiac electrophysiology: Topics of interest in 2004
2005, Revista Espanola de Cardiologia Suplementos