Special articleAssessment of three schemes for stratifying stroke risk in patients with nonvalvular atrial fibrillation☆
Section snippets
Risk-stratification schemes
We considered three sets of criteria for stratifying patients by their risk of ischemic stroke (Table 1). The criteria of the Atrial Fibrillation Investigators (AFI) were based on a multivariate pooled analysis of 1,593 participants who were assigned to placebo or to avoid anticoagulation in five randomized trials (8). During a mean follow-up of 1.4 years, 106 ischemic strokes occurred (Table 2). The AFI scheme divided patients into two strata: low risk and all others (combining intermediate
Results
Clinical features of the two cohorts from which the AFI and SPAF schemes were derived were similar, and characteristics of the SPAF-III test cohort were similar to the derivation cohorts (Table 2). Exclusion of 109 (9%) patients with prior stroke or transient ischemic attack contributed to a lower stroke rate (2.5 per 100 person-years) in the SPAF-III test cohort compared with the derivation cohorts (Table 2). During a mean follow-up of 1.8 years, 48 ischemic strokes occurred, of which 22 (46%)
Discussion
The relative efficacy and safety of warfarin and aspirin for prevention of stroke in patients with atrial fibrillation are well established (1). Accurate prediction of stroke risk, so that patients receive the most appropriate antithrombotic management, has become the salient clinical issue. We evaluated three risk-stratification schemes for the prediction of initial ischemic stroke in patients with nonvalvular atrial fibrillation. Although each scheme was able to classify low-, intermediate-,
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Cited by (95)
Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline
2022, ChestCitation Excerpt :This involves estimating the risk for ATE, encompassing stroke and systemic embolism for patients with atrial fibrillation or a mechanical heart valve, and the risk for recurrent VTE for patients with a history of VTE with perioperative interruption of anticoagulant drugs. The risk classification in Table 1 is empiric and separates patients according to estimated risk for ATE (high risk: > 10%/year; intermediate risk: 4%-10%/year; low risk: < 4%/year) and estimated risk for VTE (high risk: > 10%/month; intermediate risk: 4%-10%/month; low risk: < 2%/month); it is derived mainly from studies in a non-perioperative setting that involved patients with atrial fibrillation,29-32 a mechanical heart valve,33-35 or VTE36-38 who were not receiving anticoagulant therapy (eg, placebo instead of a VKA in patients with atrial fibrillation) or less effective antithrombotic therapy (eg, ASA instead of a VKA in patients with a mechanical heart valve).13,14,25 A perioperative risk classification for patients with coronary artery disease, particularly if they have coronary stents, is available elsewhere and is also empiric.39,40
Risk Prediction for Ischemic Stroke and Transient Ischemic Attack in Patients Without Atrial Fibrillation: A Retrospective Cohort Study
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Supported by a grant (NS 24224) from the Division of Stroke and Trauma, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland.