Letter to the editor Use of Antithrombotic Therapy in Patients With Atrial Fibrillation in Primary Care. Importance of INR Control. Response

To the Editor,

Firstly, we would like to thank Dr Leal-Hernández and Dr Marín for their interest in our study. We agree that, because patient recruitment took place between September 2009 and May 2010, the most appropriate scale to assess the risk of stroke was the CHADS₂ scale which, in fact, was the scale used in the original study.¹ In the present study, we wanted to broaden our data analysis by using the CHA₂DS₂-VASc scale, which provides better stratification of the risk of stroke, especially in patients with intermediate risk. Given that use of the CHA₂DS₂-VASc scale is recommended in the European guidelines for 2010,² current and future studies will determine the real impact of this scale both in regard to risk stratification and antithrombotic therapy use.

Dr Leal-Hernández and Dr Marín also discuss the fact that, in our study, 44.3% of patients with CHA₂DS₂-VASc 0 received anticoagulation therapy, whereas 33.5% of patients with CHA₂DS₂-VASc ≥2 did not.³ Following their analysis of recent literature, they conclude that the use of anticoagulation therapy would seem to be improving.^4–6 However, despite clear indications, a significant percentage of patients receive no anticoagulants whereas a further percentage with no indications for anticoagulation do, in fact, receive this treatment. In the latter, except in patients scheduled to undergo elective cardioversion, physicians need to stratify the risk of stroke better and should be aware of the risks anticoagulation entails. With regard to the former, these authors also indicate that an important factor in the underuse of anticoagulation is less than optimal INR control and suggest that the new oral anticoagulants could diminish this problem. While this is undeniable, it is important to understand the magnitude of the problem.

Currently, the PAULA study is under way—endorsed by the Spanish Society of Primary Care Physicians (SEMERGEN), the Spanish Society of Family and Community Medicine (semFYC) and the Spanish Society of General Practitioners (SEMG). Across Spain, the study is enrolling approximately 1000 patients in treatment with vitamin K antagonists and followed up in primary care. One of the PAULA objectives is to learn about INR control in Spain.⁷ Undoubtedly, the results from this study will help clarify how anticoagulation therapy is administered in Spain and will offer clues on the steps we need to take to improve the situation.