title: Clinical and Economic Implications of Apixaban Versus Aspirin in the Low-Risk Nonvalvular Atrial Fibrillation Patients.
abstract: OBJECTIVE
  Although recommended by guidelines, the benefits of treating patients with atrial fibrillation with a low-stroke risk score, with aspirin or anticoagulants, have not been clearly established. With advent of safer non-vitamin K antagonist oral anticoagulant, we assessed the clinical and economic implications of 5 mg BID of apixaban versus aspirin among patients with a relative low risk of stroke as assessed using the CHADS2 (congestive heart failure, hypertension, age>75, diabetes mellitus, stroke/transient ischemic attack) and CHA2DS2-VASc (congestive heart failure, hypertension, age, diabetes mellitus, stroke/transient ischemic attack, vascular disease) stroke risk classification.
  
  
  METHODS
  A previously developed and validated Markov model was adapted. A secondary analysis of the Apixaban Versus Acetylsalicylic Acid to Prevent Stroke in Atrial Fibrillation Patients Who Have Failed or Are Unsuitable for Vitamin K Antagonist Treatment (AVERROES) study was conducted to estimate event rates in different low-risk cohorts by treatment. Three cohorts (n=1000) with a CHADS2 score of 1, CHA2DS2-VASc score of 1, and CHA2DS2-VASc of score 2 to 4 were simulated to assess the number of clinical events avoided in terms of strokes and major bleeds, as well as life years gained, quality-adjusted life years gained, costs, and incremental costs per quality-adjusted life year gained.
  
  
  RESULTS
  Apixaban was associated with fewer strokes and systemic embolism versus aspirin across all subgroups; however, it caused more major bleeding events. The reduction in systemic embolism offset the increase in major bleeding events leading to increased life expectancy and quality-adjusted life year gains, achieved at an increased cost that was lower than the UK threshold of $44,400 (ie, £30,000) per quality-adjusted life year gained across the 3 cohorts examined.
  
  
  CONCLUSIONS
  Anticoagulant treatment with apixaban versus aspirin in low-risk patients, as identified using CHADS2 or CHA2DS2-VASc, is projected to increase life expectancy and provide clinical benefits that are cost effective.
authors: From the Centre for Cardiovascular Science, City Hospital, University of Birmingham, Birmingham, United Kingdom (G.Y.H.L.); Thrombosis Research Unit, Aalborg University, Aalborg, Denmark (G.Y.H.L.); Modeling and Simulation, Evidera, London, United Kingdom (T.L., T.K.); Statistics, Pfizer, New York, NY (J.M.); US Health Economics & Outcomes Research, EMD Serono, Rockland, MA (H.P.); and Division of Cardiology, University of Toronto, St. Michael's Hospital, Toronto, Ontario, Canada (P.D.).
authors: Gregory Y H
authors: GY
authors: Lip
authors: From the Centre for Cardiovascular Science, City Hospital, University of Birmingham, Birmingham, United Kingdom (G.Y.H.L.); Thrombosis Research Unit, Aalborg University, Aalborg, Denmark (G.Y.H.L.); Modeling and Simulation, Evidera, London, United Kingdom (T.L., T.K.); Statistics, Pfizer, New York, NY (J.M.); US Health Economics & Outcomes Research, EMD Serono, Rockland, MA (H.P.); and Division of Cardiology, University of Toronto, St. Michael's Hospital, Toronto, Ontario, Canada (P.D.). tereza.lanitis@evidera.com.
authors: Tereza
authors: T
authors: Lanitis
authors: From the Centre for Cardiovascular Science, City Hospital, University of Birmingham, Birmingham, United Kingdom (G.Y.H.L.); Thrombosis Research Unit, Aalborg University, Aalborg, Denmark (G.Y.H.L.); Modeling and Simulation, Evidera, London, United Kingdom (T.L., T.K.); Statistics, Pfizer, New York, NY (J.M.); US Health Economics & Outcomes Research, EMD Serono, Rockland, MA (H.P.); and Division of Cardiology, University of Toronto, St. Michael's Hospital, Toronto, Ontario, Canada (P.D.).
authors: Jack
authors: J
authors: Mardekian
authors: From the Centre for Cardiovascular Science, City Hospital, University of Birmingham, Birmingham, United Kingdom (G.Y.H.L.); Thrombosis Research Unit, Aalborg University, Aalborg, Denmark (G.Y.H.L.); Modeling and Simulation, Evidera, London, United Kingdom (T.L., T.K.); Statistics, Pfizer, New York, NY (J.M.); US Health Economics & Outcomes Research, EMD Serono, Rockland, MA (H.P.); and Division of Cardiology, University of Toronto, St. Michael's Hospital, Toronto, Ontario, Canada (P.D.).
authors: Thitima
authors: T
authors: Kongnakorn
authors: From the Centre for Cardiovascular Science, City Hospital, University of Birmingham, Birmingham, United Kingdom (G.Y.H.L.); Thrombosis Research Unit, Aalborg University, Aalborg, Denmark (G.Y.H.L.); Modeling and Simulation, Evidera, London, United Kingdom (T.L., T.K.); Statistics, Pfizer, New York, NY (J.M.); US Health Economics & Outcomes Research, EMD Serono, Rockland, MA (H.P.); and Division of Cardiology, University of Toronto, St. Michael's Hospital, Toronto, Ontario, Canada (P.D.).
authors: Hemant
authors: H
authors: Phatak
authors: From the Centre for Cardiovascular Science, City Hospital, University of Birmingham, Birmingham, United Kingdom (G.Y.H.L.); Thrombosis Research Unit, Aalborg University, Aalborg, Denmark (G.Y.H.L.); Modeling and Simulation, Evidera, London, United Kingdom (T.L., T.K.); Statistics, Pfizer, New York, NY (J.M.); US Health Economics & Outcomes Research, EMD Serono, Rockland, MA (H.P.); and Division of Cardiology, University of Toronto, St. Michael's Hospital, Toronto, Ontario, Canada (P.D.).
authors: Paul
authors: P
authors: Dorian
mesh_terms: D000368:Aged; D001241:Aspirin / Q000191:economics / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications* / Q000191:economics / Q000401:mortality; D003362:Cost-Benefit Analysis; D065427:Factor Xa Inhibitors / Q000191:economics / Q000627:therapeutic use*; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000191:economics / Q000627:therapeutic use*; D011720:Pyrazoles / Q000191:economics / Q000627:therapeutic use*; D011728:Pyridones / Q000191:economics / Q000627:therapeutic use*; D019057:Quality-Adjusted Life Years; D012307:Risk Factors; D020521:Stroke / Q000191:economics / Q000209:etiology / Q000517:prevention & control*
chemical_list: D065427:Factor Xa Inhibitors; D010975:Platelet Aggregation Inhibitors; D011720:Pyrazoles; D011728:Pyridones; C522181:apixaban; D001241:Aspirin
keywords: apixaban; aspirin; atrial fibrillation; cost effectiveness