Atrial fibrillation guidelines across the Atlantic: a comparison of the current recommendations of the European Society of Cardiology/European Heart Rhythm Association/European Association of Cardiothoracic Surgeons, the American College of Cardiology Foundation/American Heart Association/Heart Rhythm Society, and the Canadian Cardiovascular Society

Atrial fibrillation (AF), the most common sustained arrhythmia, has been a major focus for heart rhythm-related research in recent years. The evidence supporting recommendations for the management of AF has markedly increased since the publication of the 2006 ACC/AHA/ESC guidelines on AF (Supplementary material online). Therefore, the European Society of Cardiology (ESC), together with the European Heart Rhythm Association (EHRA) and the European Association of Cardiothoracic Surgeons (EACTS), mindful of a distinct regulatory, medico-legal and medical practice environment in Europe, published comprehensive new guidelines for the management of patients with AF in 2010,1,2 and a focused update of these guidelines in 2012.3 The Canadian Cardiovascular Society (CCS), based on similar considerations, published a full set of AF guidelines in 2011,4–6 which was updated in 2012.7 In parallel, the American College of Cardiology Foundation (ACCF), the American Heart Association (AHA), and the Heart Rhythm Society (HRS) issued two focused updates (Supplementary material online, references 7, 8) that were subsequently integrated into the previous 2006 ACC/AHA/ESC guidelines.8 While ACCF, AHA, and HRS have started to develop a completely new set of guidelines for AF, the present situation provides a unique opportunity to gather insight into the process that leads from new, published evidence to new recommendations. We, therefore, systematically compared the recommendations in the three sets of guidelines and tried to characterize the causes that resulted in differing recommendations. We systematically compared all recommendations published in the current versions of the guidelines of ESC, CCS, and ACCF/AHA/HRS, and classified all recommendations as identical/overlapping or differing. The ACCF/AHA/HRS and the ESC guidelines both use the same system to grade strength of recommendation and level of evidence, while the CCS guidelines use an adapted the Grading of Recommendations Assessment, Development and Evaluation (GRADE, www.gradeworkinggroup.org …