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 .
Patients with nonvalvular atrial fibrillation at low risk of stroke during treatment with aspirin: Stroke Prevention in Atrial Fibrillation III Study. The SPAF III Writing Committee for the Stroke Prevention in Atrial Fibrillation Investigators.
CONTEXT Nonvalvular atrial fibrillation ( AF ) carries an increased risk for stroke , but absolute rates of stroke vary widely within the broad spectrum of AF patients . OBJECTIVE To prospect ively vali date a risk stratification scheme identifying patients with AF with low rates of stroke when given aspirin .  DESIGN Prospect i ve cohort study with mean duration of follow-up of 2.0 years , conducted between 1993 and 1997 . SETTING Outpatient clinics affiliated with academic medical centers . PATIENTS Patients with AF categorized as " low risk " based on the absence of 4 prespecified thromboembolic risk factors : recent congestive heart failure or left ventricular fractional shortening of 25 % or less , previous thromboembolism , systolic blood pressure greater than 160 mm Hg , or female sex at age older than 75 years . INTERVENTION All participants given aspirin , 325 mg/d . MAIN OUTCOME MEASURES Ischemic stroke ( considered disabling when Rankin score was II or worse 1 - 3 months later ) and systemic embolism ( primary events ) . RESULTS Among 892 participants , the mean ( SD ) age was 67 ( 10 ) years , 78 % were men , and histories of hypertension , diabetes , and ischemic heart disease were present in 46 % , 13 % , and 16 % , respectively . The rate of primary events was 2.2 % per year ( 95 % confidence interval [ CI ] , 1.6%-3.0 % ) , of ischemic stroke was 2.0 % per year ( 95 % CI , 1.5%-2.8 % ) , and of disabling ischemic strokes was 0.8 % per year ( 95 % CI , 0.5%-1.3 % ) . Those with a history of hypertension had a higher rate of primary events ( 3.6 % per year ) than those with no history of hypertension ( 1.1 % per year ) ( P<.001 ) . The rate of disabling ischemic stroke was low in those with and without a history of hypertension ( 1.4 % per year and 0.5 % per year , respectively ) . The rate of major bleeding during aspirin therapy was 0.5 % per year . CONCLUSION Patients with AF who have relatively low rates of ischemic stroke , particularly disabling stroke , during treatment with aspirin can be reliably identified
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 .