Introduction: Bleeding complications of vitamin K antagonist (VKA) therapy are currently the most frequent iatrogenic event in France.
Objectives: The aim of the ISAM study, an international longitudinal observational survey was to evaluate the use of VKA treatment and the quality of laboratory monitoring in everyday medical practice.
Methods: In France, a representative sample of general practitioners and cardiologists selected patients with nonvalvular atrial fibrillation who had been treated with VKA for at least 60 days during the past 12 months. Physicians and patients responded to standardized questionnaires collecting retrospective data for the previous year.
Results: Overall, 43 general practitioners and 20 cardiologists recruited 278 patients who completed questionnaires. INR was at least 2 for 264 patients during the study period. During the year preceding inclusion, INR had been within the target range (i.e., between 2.0 and 3.0) 59% of the time and above 3.0 27%. Physicians reported having giving approximately half their patients written recommendations about the VKA dosage regimen, but only 3% supplied a specific VKA information and monitoring booklet. Most patients (65%) reported receiving information on VKA therapy from their general practitioners, although 18% said they had not been informed about their treatment, 44% did not know their target INR, and 66% were unaware that bleeding events were a matter of concern. Finally, 45% of patients reported carrying a card indicating that they were taking VKA.
Conclusion: Overall, these results show that better education of both physicians and patients could help to improve management, appropriate use and laboratory monitoring of VKA treatment.