Journal of Thrombosis and Thrombolysis

, Volume 23, Issue 2, pp 83–91 | Cite as

Descriptive analysis of the process and quality of oral anticoagulation management in real-life practice in patients with chronic non-valvular atrial fibrillation: the international study of anticoagulation management (ISAM)

  • Jack AnsellEmail author
  • Jennifer Hollowell
  • Vittorio Pengo
  • Fernando Martinez-Brotons
  • Jaime Caro
  • Ludovic Drouet



Expert oral anticoagulation management is the key to good outcomes and is performed variably in different health care systems throughout the world. We set out to assess the quality of anticoagulation management in five countries in patients receiving vitamin K antagonists (VKAs) for stroke prophylaxis in chronic non-valvular atrial fibrillation (NVAF), and to compare the anticoagulation management practices in these countries.

Methods and results

This was a retrospective, multi-centre cohort study in the United States, Canada, France, Italy, and Spain. About 1,511 patients were randomly recruited from representative practices (routine medical care (RMC) in the US, Canada, and France; anticoagulation clinics in Italy and Spain) and data pertaining to their oral anticoagulation care were abstracted from their medical records. The predominant anticoagulant in use was warfarin in the US, Canada, and Italy; acenocoumarol in Spain; and fluindione in France. Documentation of care was poor in the US, Canada, and France, countries where RMC was studied. Percent INRs or time-in-therapeutic range was greater in the two anticoagulation clinic samples compared with the RMC samples.


Oral anticoagulation care varies considerably from country to country. Findings suggest that anticoagulation clinic care (ACC) may provide better outcomes as assessed by international normalized ratio (INR) time-in-range. Physicians tend to under treat more than over treat. Finally, documentation of care is often inadequate.

Condensed Abstract Oral anticoagulation management (routine medical care or anticoagulation clinic care) was retrospectively assessed in 5 countries using a uniform, structured assessment tool. Major management differences were detected, especially between anticoagulation clinic care and routine care. Documentation was often a problem in the latter setting. Less time in therapeutic INR range was noted in routine medical care. Findings suggest that anticoagulation clinic care may provide better outcomes as assessed by international normalized ratio (INR) time-in-range. Physicians tend to under treat more than over treat. Finally, documentation of care is often inadequate.


Oral anticoagulation Warfarin International normalized ratio Atrial fibrillation 



We express our sincere thanks to the participating physicians and clinics and to the local study co-ordinators (Ole Hauch and Gail Wygant, USA; Amin Haiderali, Canada; Hervé Lamarque and Maud Woessner, France; Alessandra Cheli and Cristina Negrini, Italy; Rosario Marazuela, Spain), and Jonas Carlsson for statistical support. This study was funded by AstraZeneca.


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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Jack Ansell
    • 1
    Email author
  • Jennifer Hollowell
    • 2
  • Vittorio Pengo
    • 3
  • Fernando Martinez-Brotons
    • 4
  • Jaime Caro
    • 5
  • Ludovic Drouet
    • 6
  1. 1.Department of Medicine, E113Boston University Medical CenterBostonUSA
  2. 2.AstraZeneca R & DMolndalSweden
  3. 3.University of PadovaPadovaItaly
  4. 4.Hospital Universitario de BellvitgeL’Hospitalet de LlobregatBarcelonaSpain
  5. 5.Caro Research InstituteConcordUSA
  6. 6.Hôpital LaroboisièreParisFrance

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