Discussion The results of this systematic review have the potential to benefit thous and s of patients worldwide as well as healthcare systems and healthcare economy .
Background Atrial fibrillation is the most common arrhythmia of the heart with a prevalence of approximately 2 % in the western world .
Atrial flutter , another arrhythmia , occurs less often with an incidence of approximately 200,000 new patients per year in the USA .
Patients with atrial fibrillation and atrial flutter have an increased risk of death and morbidities .
The management of atrial fibrillation and atrial flutter is often based on interventions aim ing at either a rhythm control strategy or a rate control strategy .
The evidence on the comparable effects of these strategies is unclear .
This protocol for a systematic review aims at identifying the best overall treatment strategy for atrial fibrillation and atrial flutter .
Apixaban in patients with atrial fibrillation.
BACKGROUND Vitamin K antagonists have been shown to prevent stroke in patients with atrial fibrillation . However , many patients are not suitable c and i date s for or are unwilling to receive vitamin K antagonist therapy , and these patients have a high risk of stroke . Apixaban , a novel factor Xa inhibitor , may be an alternative treatment for such patients . METHODS In a double-blind study , we r and omly assigned 5599 patients with atrial fibrillation who were at increased risk for stroke and for whom vitamin K antagonist therapy was unsuitable to receive  apixaban ( at a dose of 5 mg twice daily ) or aspirin ( 81 to 324 mg per day ) , to determine whether apixaban was superior . The mean follow up period was 1.1 years . The primary outcome was the occurrence of stroke or systemic embolism . RESULTS Before enrollment , 40 % of the patients had used a vitamin K antagonist .  The data and safety monitoring board recommended early termination of the study because of a clear benefit in favor of apixaban . There were 51 primary outcome events ( 1.6 % per year ) among patients assigned to apixaban and 113 ( 3.7 % per year ) among those assigned to aspirin ( hazard ratio with apixaban , 0.45 ; 95 % confidence interval [ CI ] , 0.32 to 0.62 ; P<0.001 ) . The rates of death were 3.5 % per year in the apixaban group and 4.4 % per year in the aspirin group ( hazard ratio , 0.79 ; 95 % CI , 0.62 to 1.02 ; P=0.07 ) . There were 44 cases of major bleeding ( 1.4 % per year ) in the apixaban group and 39 ( 1.2 % per year ) in the aspirin group ( hazard ratio with apixaban , 1.13 ; 95 % CI , 0.74 to 1.75 ; P=0.57 ) ; there were 11 cases of intracranial bleeding with apixaban and 13 with aspirin . The risk of a first hospitalization for cardiovascular causes was reduced with apixaban as compared with aspirin ( 12.6 % per year vs. 15.9 % per year , P<0.001 ) . The treatment effects were consistent among important subgroups . CONCLUSIONS In patients with atrial fibrillation for whom vitamin K antagonist therapy was unsuitable , apixaban reduced the risk of stroke or systemic embolism without significantly increasing the risk of major bleeding or intracranial hemorrhage . ( Funded by Bristol-Myers Squibb and Pfizer ; Clinical Trials.gov number , NCT00496769 . )
Discussion The results of this systematic review have the potential to benefit thous and s of patients worldwide as well as healthcare systems and healthcare economy .
Background Atrial fibrillation is the most common arrhythmia of the heart with a prevalence of approximately 2 % in the western world .
Atrial flutter , another arrhythmia , occurs less often with an incidence of approximately 200,000 new patients per year in the USA .
Patients with atrial fibrillation and atrial flutter have an increased risk of death and morbidities .
The management of atrial fibrillation and atrial flutter is often based on interventions aim ing at either a rhythm control strategy or a rate control strategy .
The evidence on the comparable effects of these strategies is unclear .
This protocol for a systematic review aims at identifying the best overall treatment strategy for atrial fibrillation and atrial flutter .