Few models had addressed the cumulative nature of risk factors where a combination of risk factors would confer a greater risk than either factor alone .
In patients at high risk of stroke , anticoagulation is cost effective , but not for those with a low risk of stroke .
The risk of stroke in atrial fibrillation ( AF ) needs to be assessed in each patient to determine the clinical and cost-effectiveness of thromboprophylaxis , with the aim of appropriate use of antithrombotic therapy .
To achieve this , stroke risk factors in AF population s need to be identified and stroke risk stratification models have been devised on the basis of these risk factors .
In this article , we firstly provide a systematic review of studies examining the attributable stroke risk of various clinical , demographic and echocardiographic patient characteristics in AF population s. Secondly , we performed a systematic review of published stroke risk stratification models , in terms of the results of the review of stroke risk factors and their ability to accurately discriminate between different levels of stroke risk .
Warfarin versus aspirin for stroke prevention in an elderly community population with atrial fibrillation (the Birmingham Atrial Fibrillation Treatment of the Aged Study, BAFTA): a randomised controlled trial
BACKGROUND Anticoagulants are more effective than antiplatelet agents at reducing stroke risk in patients with atrial fibrillation , but whether this benefit outweighs the increased risk of bleeding in elderly patients is unknown . We assessed whether warfarin reduced risk of major stroke , arterial embolism , or other intracranial haemorrhage compared with aspirin in elderly patients . METHODS 973 patients aged 75 years or over ( mean age 81.5 years , SD 4.2 ) with atrial fibrillation were recruited from primary care and r and omly assigned to warfarin ( target international normalised ratio 2 - 3 ) or aspirin ( 75 mg per day ) . Follow-up was for a mean of 2.7 years ( SD 1.2 ) . The primary endpoint was fatal or disabling stroke ( ischaemic or haemorrhagic ) , intracranial haemorrhage , or clinical ly significant arterial embolism . Analysis was by intention to treat . This study is registered as an International St and ard R and omised Controlled Trial , number IS RCT N89345269 . FINDINGS There were 24 primary events ( 21 strokes , two other intracranial haemorrhages , and one systemic embolus ) in people assigned to warfarin and 48 primary events ( 44 strokes , one other intracranial haemorrhage , and three systemic emboli ) in people assigned to aspirin ( yearly risk 1.8%vs 3.8 % , relative risk 0.48 , 95 % CI 0.28 - 0.80 , p=0.003 ; absolute yearly risk reduction 2 % , 95 % CI 0.7 - 3.2 ) . Yearly risk of extracranial haemorrhage was 1.4 % ( warfarin ) versus 1.6 % ( aspirin ) ( relative risk 0.87 , 0.43 - 1.73 ; absolute risk reduction 0.2 % , -0.7 to 1.2 ) . INTERPRETATION These data support the use of anticoagulation therapy for people aged over 75 who have atrial fibrillation , unless there are contraindications or the patient decides that the benefits are not worth the inconvenience
Few models had addressed the cumulative nature of risk factors where a combination of risk factors would confer a greater risk than either factor alone .
In patients at high risk of stroke , anticoagulation is cost effective , but not for those with a low risk of stroke .
The risk of stroke in atrial fibrillation ( AF ) needs to be assessed in each patient to determine the clinical and cost-effectiveness of thromboprophylaxis , with the aim of appropriate use of antithrombotic therapy .
To achieve this , stroke risk factors in AF population s need to be identified and stroke risk stratification models have been devised on the basis of these risk factors .
In this article , we firstly provide a systematic review of studies examining the attributable stroke risk of various clinical , demographic and echocardiographic patient characteristics in AF population s. Secondly , we performed a systematic review of published stroke risk stratification models , in terms of the results of the review of stroke risk factors and their ability to accurately discriminate between different levels of stroke risk .