Excerpt

The Veterans Health Administration (VHA) System serves a largely older, male population with a high prevalence of chronic atrial fibrillation (AF) and venous thromboembolism (VTE). Many veterans with chronic AF have risk profiles for stroke that, according to current clinical guidelines, place them in a risk group where chronic anticoagulation is recommended. Adjusted-dose warfarin has been the preferred approach to chronic anticoagulation in the VHA, and in many VHA settings, specialized therapeutic drug-monitoring services provide high-quality warfarin treatment. However, the advent of newer anticoagulants with the promise of simplified long-term anticoagulation requires reconsideration of current treatment practices. The purpose of this systematic review was to study the comparative effectiveness of warfarin and the newer oral anticoagulants used for the long-term prevention and treatment of arterial and venous thromboembolism. An evaluation of newer oral anticoagulants for VTE prophylaxis in the perioperative period will be the subject of a later report.

Contents

• PREFACE
• EXECUTIVE SUMMARY
  • BACKGROUND
  • METHODS
  • DATA SYNTHESIS
  • RATING THE BODY OF EVIDENCE
  • PEER REVIEW
  • RESULTS
  • RECOMMENDATIONS FOR FUTURE RESEARCH
  • CONCLUSION
  • ABBREVIATIONS TABLE
• INTRODUCTION
  • CHRONIC ATRIAL FIBRILLATION AND STROKE
  • VENOUS THROMBOEMBOLISM
  • MECHANICAL HEART VALVES AND THROMBOSIS
  • THERAPEUTIC OPTIONS FOR ANTICOAGULATION
  • OBJECTIVE OF THIS REPORT
• METHODS
  • TOPIC DEVELOPMENT
  • ANALYTIC FRAMEWORK
  • SEARCH STRATEGY
  • STUDY SELECTION
  • DATA ABSTRACTION
  • QUALITY ASSESSMENT
  • DATA SYNTHESIS
  • RATING THE BODY OF EVIDENCE
  • PEER REVIEW
• RESULTS
  • LITERATURE SEARCH
  • STUDY CHARACTERISTICS
  • KEY QUESTION 1 For patients with chronic nonvalvular AF, what is the comparative effectiveness of long-term anticoagulation using newer oral anticoagulants versus warfarin on stroke incidence, mortality, health-related quality of life (HRQOL), and patient treatment experience?
  • KEY QUESTION 2 For patients with venous thromboembolism, are there differential effects of newer oral anticoagulants versus warfarin or low molecular weight heparins on recurrent thromboembolism, mortality, HRQOL, and patient treatment experience?
  • KEY QUESTION 3 For patients with mechanical heart valves, what is the comparative effectiveness of newer anticoagulants versus warfarin on the incidence of thromboembolic complications, mortality, HRQOL, and patient treatment experience?
  • KEY QUESTION 4 When used for long-term anticoagulation treatment, what is the nature and frequency of adverse effects for newer anticoagulants versus warfarin?
  • RESULTS FROM OBSERVATIONAL STUDIES
  • SUMMARY OF FDA BULLETINS
• SUMMARY AND DISCUSSION
  • SUMMARY OF EVIDENCE BY KEY QUESTION
  • CLINICAL AND POLICY IMPLICATIONS
  • STRENGTHS AND LIMITATIONS
  • RECOMMENDATIONS FOR FUTURE RESEARCH
• REFERENCES
• APPENDIX A SEARCH STRATEGIES
• APPENDIX B STUDY SELECTION FORM
• APPENDIX C EXCLUDED STUDIES
• APPENDIX D SAMPLE DATA EXTRACTION FORMS
• APPENDIX E PEER REVIEW COMMENTS
• APPENDIX F ONGOING CLINICAL TRIALS
• APPENDIX G CRITERIA USED IN QUALITY ASSESSMENT
• APPENDIX H GLOSSARY

Medical Editor: Liz Wing, MA

Prepared for: Department of Veterans Affairs, Veterans Health Administration, Quality Enhancement Research Initiative, Health Services Research & Development Service, Washington, DC 20420. Prepared by: Evidence-based Synthesis Program (ESP) Center, Durham Veterans Affairs Healthcare System, Durham, NC, John W. Williams Jr., M.D., M.H.Sc., Director.

Suggested citation:

Adam SS, McDuffie JR, Ortel TL, Nagi A, Williams JW Jr. Comparative Effectiveness of Warfarin and Newer Oral Anticoagulants for the Long-term Prevention and Treatment of Arterial and Venous Thromboembolism. VA-ESP Project #09-010; 2012.

This report is based on research conducted by the Evidence-based Synthesis Program (ESP) Center located at the Durham VA Medical Center, Durham, NC, funded by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Quality Enhancement Research Initiative. The findings and conclusions in this document are those of the author(s) who are responsible for its contents; the findings and conclusions do not necessarily represent the views of the Department of Veterans Affairs or the United States government. Therefore, no statement in this article should be construed as an official position of the Department of Veterans Affairs. Potential conflicts of interest: Dr. Ortel: Grants: GlaxoSmithKline, Eisai, Daichi Sankyo, Pfizer; Consultancy: Boehringer Ingelheim. No other investigators have any affiliations or financial involvement (e.g., employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties) that conflict with material presented in the report.