Comments on the Spanish Society of Cardiology Critical Review of the ESC 2010 Clinical Practice Guidelines on Atrial Fibrillation. Response

To the Editor,

We have read with great interest the comments given by professors Lip and Camm regarding our recent critical review of the 2010 atrial fibrillation (AF) guidelines from the ESC,¹ and we would like to thank them for their contributions to our article, which may clarify certain aspects of this subject that were left unresolved, in our opinion, by the guidelines. First of all, we would like to say that we do not refute that female sex, arterial hypertension, heart failure, and vascular disease can all increase the risk of embolism in patients with AF, but it is not clear whether this is the case only in certain situations or as a general rule. As the authors themselves and the guidelines of the ESC recognize, heart failure in the absence of left ventricular systolic dysfunction, controlled hypertension with no ventricular hypertrophy, a diagnosis of angina (with no other evidence of vascular disease), and female sex with no other risk factors for embolism and age <65 years may not constitute significant risk. In fact, in their letter Lip and Camm state that female sex as a lone risk factor, and therefore a CHA₂DS₂-VASc score of 1, may not require anticoagulant therapy. However, although the text of the ESC guidelines contains this same idea, the tables of recommendations (Tables 8 and 9) include anticoagulation for a score of 1 as a general rule, without specifying any details. We believe that this might confuse doctors reading the guidelines and we assume that it will be clarified in the updated version of the ESC guidelines on AF coming out in 2012. We can agree “in general terms” that the CHA₂DS₂-VASc scale can identify additional subgroups not covered by the CHADS₂ scale and better categorizes patients with a low (0) and high (2 or more) embolic risk score. However, in addition to the fact that not all studies agree that a CHA₂DS₂-VASc score of 1 reflects a greater risk of embolism,² the greatest caution against applying this standard is the total lack of evidence that anticoagulation therapy in patients with a CHADS₂ ≤2 and a low CHA₂DS₂-VASc (1-2) score provides a significant net clinical benefit if we assess the hypothetical decrease in embolic events versus the possible increase in hemorrhagic events. Furthermore, this analysis does not address the economic cost-benefit, especially if the new oral anticoagulants are prescribed.

With regard to the recommendations on dronedarone, although the guidelines do not explicitly recommend its use in patients with permanent AF, this is considered reasonable therapy for long-term control of heart rate (IIA, evidence level B), which could lead to confusion. The publication of the PALLAS study³ and the recent recommendations from medications agencies, compiled in our article,¹ have resolved these questions and clarified, at least for the time being, the role of dronedarone in AF by confirming that the importance given by the guidelines to this drug was hasty and unprecedented in the history of ESC guidelines.

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