Canadian Journal of Cardiology
Clinical Research| Volume 32, ISSUE 3, P336-343, March 2016

The Risk Stratification and Stroke Prevention Therapy Care Gap in Canadian Atrial Fibrillation Patients

Published:October 14, 2015DOI:



      Canadian atrial fibrillation (AF) guidelines recommend that all AF patients be risk stratified with respect to stroke and bleeding, and that most should receive antithrombotic therapy.


      As part of the Canadian Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation (FREEDOM AF) chart audit, data were collected on 4670 patients ≥ 18 years old without significant valvular heart disease from the primary care practices of 474 physicians (February to September, 2011).


      Physicians did not provide an estimate of stroke and bleeding risk in 15% and 25% of patients, respectively. When risks were provided, they were on the basis of a predictive stroke and bleeding risk index in only 50% and 26% of patients, respectively. There were over- and underestimation of stroke and bleeding risk in a large proportion of patients. Antithrombotic therapy included warfarin (90%); 24% of patients had a time in the therapeutic range (TTR) < 50%, 9% between 50% and 60%, 11% between 60% and 70%, and 56% had a TTR ≥ 70%.


      In a large Canadian AF population, primary care physicians did not provide a stroke or bleeding risk in a substantial proportion of their AF patients. When estimates were provided, they were on the basis of a predictive stroke and bleeding risk index in less than half of the patients. Furthermore, there was under- and overestimation of stroke and bleeding risk in a substantial proportion of patients. As many as 1 in 3 patients receiving warfarin have their TTR < 60%. These findings suggest an opportunity to enhance knowledge translation to primary care physicians.



      Selon les lignes directrices canadiennes sur la fibrillation auriculaire (FA), il est recommandé que tous les patients fassent l’objet d’une stratification du risque relativement aux accidents vasculaires cérébraux (AVC) et aux hémorragies et que la plupart d’entre eux reçoivent un traitement antithrombotique.


      Dans le cadre du projet canadien de revue de dossiers médicaux intitulé FREEDOM AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation), des données ont été recueillies sur 4670 patients âgés de 18 ans ou plus ne présentant pas de valvulopathie importante à partir de dossiers tenus par 474 médecins de soins primaires (de février à septembre 2011).


      Les médecins n’avaient indiqué aucune donnée relative au risque d’AVC et d’hémorragie dans 15 % et 25 % des cas, respectivement. Lorsqu’il y avait mention du risque, celui-ci était basé sur un indice de prédiction du risque d’AVC et d’hémorragie pour seulement 50 % et 26 % des patients, respectivement. En outre, dans une forte proportion des cas, le risque d’AVC et d’hémorragie avait été soit surestimé, soit sous-estimé. Parmi les traitements antithrombotiques administrés, on comptait notamment la warfarine (90 %); 24 % des patients recevant ce traitement avaient un temps dans la marge thérapeutique (TMT) inférieur à 50 %, 9 % des patients avaient un TMT entre 50 et 60 %, 11 % des patients avaient un TMT entre 60 et 70 %, et 56 % des patients avaient un TMT égal ou supérieur à 70 %.


      Dans une importante population de patients canadiens, les médecins de soins primaires n’ont pas indiqué de risque d’AVC et d’hémorragie pour une grande proportion des patients atteints de FA, et lorsqu’un tel risque était indiqué, il était basé sur un indice de prédiction du risque d’AVC et d’hémorragie pour moins de la moitié des patients. De plus, il y avait eu surestimation ou sous-estimation du risque d’AVC et d’hémorragie pour une importante proportion de patients. Enfin, chez les patients traités par la warfarine, 1 sur 3 avait un TMT inférieur à 60 %. De tels résultats suggèrent qu’il serait souhaitable d’améliorer la formation des médecins de soins primaires dans ce domaine d’application.
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