Conclusions and Relevance Although screening with ECG can detect previously unknown cases of atrial fibrillation , it has not been shown to detect more cases than screening focused on pulse palpation .
Treatments for atrial fibrillation reduce the risk of stroke and all-cause mortality and increase the risk of bleeding , but trials have not assessed whether treatment of screen-detected asymptomatic older adults results in better health outcomes than treatment after detection by usual care or after symptoms develop
Importance Atrial fibrillation is the most common arrhythmia and increases the risk of stroke .
Objective To review the evidence on screening for nonvalvular atrial fibrillation with electrocardiography ( ECG ) and stroke prevention treatment in asymptomatic adults 65 years or older to inform the US Preventive Services Task Force .
Canadian Atrial Fibrillation Anticoagulation (CAFA) Study.
The Canadian Atrial Fibrillation Anticoagulation Study was a r and omized double-blind placebo-controlled trial to assess the potential of warfarin to reduce systemic thromboembolism and its inherent risk of hemorrhage . As a result of the publication of two other " positive " studies of similar design and objective , this study was stopped early before completion of its planned recruitment of 630 patients . There were 187 patients r and omized to warfarin and 191 to placebo .  Permanent discontinuation of study medication occurred in 26 % of warfarin-treated and 23 % of placebo-treated patients . The target range of the international normalized ratio was 2 to 3 . For the warfarin-treated patients , the international normalized ratio was in the target range 43.7 % of the study days , above it 16.6 % of the study days and below it 39.6 % of the study days . Fatal or major bleeding occurred at annual rates of 2.5 % in warfarin-treated and 0.5 % in placebo-treated patients . Minor bleeding occurred in 16 % of patients receiving warfarin and 9 % receiving placebo . The primary outcome event cluster was nonlacunar stroke , non central nervous systemic embolism and fatal or intracranial hemorrhage . Events were included in the primary analysis of efficacy if they occurred within 28 days of permanent discontinuation of the study medication . The annual rates of the primary outcome event cluster were 3.5 % in warfarin-treated and 5.2 % in placebo-treated patients , with a relative risk reduction of 37 % ( 95 % confidence limits , -63.5 % , 75.5 % , p = 0.17 ) . ( ABSTRACT TRUNCATED AT 250 WORDS
Conclusions and Relevance Although screening with ECG can detect previously unknown cases of atrial fibrillation , it has not been shown to detect more cases than screening focused on pulse palpation .
Treatments for atrial fibrillation reduce the risk of stroke and all-cause mortality and increase the risk of bleeding , but trials have not assessed whether treatment of screen-detected asymptomatic older adults results in better health outcomes than treatment after detection by usual care or after symptoms develop
Importance Atrial fibrillation is the most common arrhythmia and increases the risk of stroke .
Objective To review the evidence on screening for nonvalvular atrial fibrillation with electrocardiography ( ECG ) and stroke prevention treatment in asymptomatic adults 65 years or older to inform the US Preventive Services Task Force .