http://informahealthcare.com/pgm ISSN: 0032-5481 (print), 1941-9260 (electronic) Postgrad Med, 2015; Early Online: 1–4 DOI: 10.1080/00325481.2015.1029863
REVIEW
Implications for your practice: Important changes in the 2014 guideline for the management of patients with atrial fibrillation Rachel Littrell and Greg Flaker
Postgraduate Medicine Downloaded from informahealthcare.com by Kainan University on 04/23/15 For personal use only.
University of Missouri – Cardiology, Columbia, MO, USA Abstract
Keywords
Atrial fibrillation (AF) is an increasingly common cardiac arrhythmia, currently affecting more than 5 million Americans. Management of patients with AF can be complex, with key strategies including selecting rhythm control versus heart rate control and reducing the patient’s risk of stroke or other systemic embolization. The American Heart Association, American College of Cardiology, and Heart Rhythm Society released 2014 Guideline for the Management of Patients with Atrial Fibrillation, which outlines several new recommendations with important clinical implications. Among these are a new recommendation to use the CHA2DS2-Vasc score for stroke risk assessment, rather than the previously advised CHADS2 score, expansion of anticoagulation options in selected patients, decreased emphasis on the role of aspirin, and an increased emphasis on the role of catheter ablation.
Atrial fibrillation, atrial flutter, anticoagulation, warfarin
Introduction Atrial fibrillation (AF) is an increasingly common cardiac arrhythmia, currently affecting more than 5 million Americans [1]. As the population ages, the incidence and prevalence of AF are expected to continue to rise [2]. Wellestablished risk factors associated with AF include increasing age, male gender, obesity, hypertension, left ventricular dysfunction, and alcohol consumption, among others [3]. Management of patients with AF can be complex. The rhythm may be paroxysmal, persistent, or permanent. Patients may be wholly asymptomatic or present with debilitating symptoms that affect quality of life [4]. The cornerstones of management center on selecting rhythm control versus heart rate control and reducing the patient’s risk of stroke or other systemic embolization. Recently released updated guidelines for management of patients with AF help in addressing and clarifying some key management issues [5]. Further, there are some important changes from the earlier 2006 guidelines [6] and some important differences from European guidelines. Although a comprehensive review of the updated guidelines is beyond the scope of this article, what follows will highlight some important changes in the guidelines that impact clinical practice.
How do we classify AF? Identification of patients with AF occurs in a variety of settings. The rhythm may be detected as an incidental finding
History Received 16 December 2014 Accepted 12 March 2015 Published online 27 March 2015
on an electrocardiogram obtained for another reason. Telemetry monitoring for hospital inpatients or patients presenting for surgery may reveal AF. AF may also be detected in patients with other monitoring devices, such as Holter monitors, event monitors, loop recorders, pacemakers, implantable cardiac defibrillators, or others. Still other patients may present urgently to clinic or the emergency department with symptomatic AF, embolic complication, or heart failure. The American Heart Association, American College of Cardiology, and Heart Rhythm Society 2014 guideline makes no mention of the duration of AF required to make a diagnosis; the diagnosis of AF requires only an electrocardiogram documenting the arrhythmia. Once the diagnosis is established, attention turns to classification. Because this arrhythmia presents in many different ways, over the years there have been many different terms used to describe and classify AF [7]. These include “acute” versus “chronic”, “lone AF”, “first-detected”, “self-terminating”, “recurrent”, “focal”, and many others. There continues to be a great deal of heterogeneity regarding definition and classification of AF, as exemplified by a recent survey of physicians who treat patients with this arrhythmia [8]. Clinical classification of types of AF can be useful in determining the treatment strategies. For example, a rhythm control strategy might be considered in a patient with paroxysmal or persistent AF; a rate control strategy is pursued in a patient with permanent AF. Although some have doubted the accuracy of the clinical classification of types of AF [9], the current guidelines simplify the classification and definitions
Correspondence: Greg Flaker, University of Missouri – Cardiology, one hospital Dr CE306, Columbia, MO 65212, USA. E-mail: [email protected] 2015 Informa UK Ltd.
2
R. Littrell & G. Flaker
Postgrad Med, 2015; Early Online:1–4
Table 1. Classification [5]. Term definition Paroxysmal AF Persistent AF Long-standing persistent AF Permanent AF
Non-valvular AF
AF that terminates spontaneously or with intervention within 7 days of onset Episodes may recur with variable frequency Continuous AF that is sustained >7 days Continuous AF of >12 months duration Permanent AF is used when there has been a joint decision by the patient and clinician to cease further attempts to restore and/or maintain sinus rhythm Acceptance of AF represents a therapeutic attitude on the part of the patient and clinician rather than an inherent pathophysiological attribute of the AF Acceptance of AF may change as symptoms, the efficacy of therapeutic interventions, and patient and clinician preferences evolve AF in the absence of rheumatic mitral stenosis, a mechanical or bioprosthetic heart valve, or mitral valve repair
Postgraduate Medicine Downloaded from informahealthcare.com by Kainan University on 04/23/15 For personal use only.
Abbreviation: AF = Atrial fibrillation.
for how we describe AF. The new classifications are based primarily on duration of episodes. If an episode of AF terminates (either spontaneously or with intervention) within 7 days of onset, it is considered paroxysmal. Persistent AF describes episodes that last >7 days. If the arrhythmia persists >12 months, it is considered long-standing persistent AF. The term “permanent AF” is used to describe patients for whom no further attempts at restoring or maintaining sinus rhythm will be made. Guideline authors do note that permanent AF patients may be reclassified as symptoms, treatments and their preferences evolve (Table 1). Non-valvular AF is frequently misinterpreted by clinicians from a definition perspective. In clinical trials non-valvular AF included patients with significant valve disease but excluded patients with clinically significant (moderate to severe) mitral stenosis or patients who required anticoagulation such as patients with prosthetic mechanical heart valves. The in-between cases are those with bioprosthetic valves or those with mitral valve repair. Some of these patients were included in the clinical trials but there is little in the way of guidelines in these patients. Until additional data are provided, it might be best to use warfarin in these patients.
Who needs anticoagulation? One of the most important questions addressed by physicians caring for patients with AF is to decide for whom to recommend oral anticoagulation. Anticoagulation is recommended based on the individual patient’s risk of stroke or other systemic embolism. This risk is determined based on risk factors once AF is present, and without regard to whether it is paroxysmal, persistent, or permanent. The 2014 guidelines recommend (as a class I recommendation) using the CHA2DS2-Vasc score for stroke risk assessment, rather than the CHADS2 score recommended in 2006 guidelines, for patients with non-valvular AF [5]. The CHADS2 score [10] assigns 1 point each for the presence of congestive heart failure, hypertension, age ‡75 years, and diabetes mellitus and assigns 2 points for history of stroke or transient ischemic attack. Anticoagulation with warfarin is recommended for a CHADS2 score of ‡2, and either warfarin or aspirin should be considered with a CHADS2 score of 1. Aspirin is recommended for a CHADS2 score of 0. The CHA2DS2-Vasc [11] score is a newer model that adds other risk factors including female gender, age 65–74 years,
and presence of vascular disease (Table 2). There is also greater importance placed on age ‡75 years, given the increased risk of stroke or other systemic embolism associated with aging. A score of ‡2 is considered high risk, and anticoagulation is recommended for these patients. Anticoagulation should be considered for patients with a CHA2DS2Vasc score of 1, who are considered to be at intermediate risk. No anticoagulation is recommended for patients with a CHA2DS2-Vasc score of 0, who are considered to be at low risk. Updated 2012 European Society of Cardiology (ESC) guidelines similarly recommend anticoagulation for patients with a CHA2DS2-Vasc score of ‡2, but also recommend anticoagulation in patients with a CHA2DS2-Vasc score of 1 after assessment of bleeding risk and patient preferences [12]. The Canadian Cardiovascular Society guidelines for the management of AF, updated in 2014, also recommend an algorithm based on CHADS2 risk factors for determining which patients benefit from oral anticoagulation. In contrast to ESC guidelines, Canadian guidelines do not consider female sex or vascular disease alone as sufficient to recommend oral anticoagulant therapy. Canadian guidelines do, however, recommend oral anticoagulation for patients aged ‡65 years. Canadian guidelines favor novel oral anticoagulants over warfarin in patients with non-valvular AF [13]. Under the CHA2DS2-Vasc scoring system, fewer patients are considered intermediate risk, and therefore anticoagulation is recommended more frequently than when using the CHADS2 score.
Should aspirin be recommended for prevention of thromboembolism? In the 2006 guideline, aspirin was recommended for patients with CHADS2 score of 0, and aspirin or warfarin was Table 2. CHA2DS2-Vasc score. Risk factor Congestive heart failure/left ventricular dysfunction Hypertension Age ‡75 years Diabetes mellitus Stroke/transient ischemic attack/thromboembolism Vascular disease (prior myocardial infarction, peripheral artery disease, or aortic plaque) Age 65–74 years Sex category (i.e. female gender)
Score 1 1 2 1 2 1 1 1
DOI: 10.1080/00325481.2015.1029863
Guideline for the management of patients with atrial fibrillation
Postgraduate Medicine Downloaded from informahealthcare.com by Kainan University on 04/23/15 For personal use only.
recommended for patients with CHADS2 score of 1. Aspirin 81–325 mg/day was also recommended for patients who could not take warfarin [14]. In the new guideline, aspirin has a reduced role. For patients with a CHA2DS2-Vasc score of 0, no anticoagulation is recommended. For patients with a CHA2DS2-Vasc score of 1, it is reasonable to consider anticoagulation, aspirin, or no anticoagulation. Newer European guidelines also have a reduced role for aspirin. According to 2012 ESC guidelines, aspirin should only be considered in patients who refuse any oral anticoagulant, or who cannot tolerate anticoagulants for reasons other than bleeding [12].
Which anticoagulant should be prescribed? In patients for whom anticoagulation is recommended, the new guideline offers options beyond warfarin. Options include warfarin (with goal international normalized ratio of 2.0 to 3.0) or a newer agent including dabigatran, rivaroxaban, or apixaban. The use of a newer agent is recommended for patients who cannot maintain therapeutic levels of warfarin. As per the guideline, warfarin remains the agent of choice in patients with end-stage renal disease (creatinine clearance 95 ml/minute. Warfarin also remains the anticoagulant of choice in patients with prosthetic heart valves. The European guideline expresses a stronger preference for novel agents, stating that the novel oral anticoagulants available to date have all shown noninferiority to warfarin, with better safety; thus, novel oral anticoagulants are recommended as “broadly preferable to vitamin K antagonists in the vast majority of patients with non-valvular atrial fibrillation when used as studied in the clinical trials performed so far [11]”. Canadian guidelines similarly recommend novel oral anticoagulants over warfarin in patients with nonvalvular AF. In patients with AF who require percutaneous coronary intervention, bare metal stents may be considered to minimize the duration of dual antiplatelet therapy (class IIb). In patients who receive stents, it may be reasonable to continue clopidogrel and anticoagulation, without the use of aspirin (also class IIb). Bleeding risk is always a concern when prescribing an anticoagulant. The 2014 guideline does not emphasize assessment of bleeding risk. The 2012 ESC guideline, on the other hand, recommends using a scoring system to evaluate bleeding risk and adjusting the dose if bleeding risk is high.
Rhythm control or rate control? Both rate control and rhythm control strategies offer the opportunity to improve symptoms and quality of life, and the decision for which strategy to pursue is made between
3
the physician and each individual patient. Both ESC and Canadian guidelines outline recommendations for pursuing rhythm control when needed to improve symptoms and quality of life. The 2014 guideline by contrast offers less direction regarding when to pursue a rhythm control strategy. In patients for whom a rhythm control strategy is selected, cardioversion is a recommended strategy to restore sinus rhythm. If unsuccessful, it is reasonable to adjust electrode location or pressure and reattempt, or to try again after administering an antiarrhythmic medication. It may also be reasonable to perform repeated cardioversion if the patient can maintain sinus rhythm “for a clinically meaningful period” between procedures. Restoration of sinus rhythm does not, however, obviate the need for anticoagulation. All patients undergoing cardioversion should be anticoagulated for at least 4 weeks after cardioversion, with one exception. The 2014 guideline states that patients who have AF or atrial flutter for
REVIEW
Implications for your practice: Important changes in the 2014 guideline for the management of patients with atrial fibrillation Rachel Littrell and Greg Flaker
Postgraduate Medicine Downloaded from informahealthcare.com by Kainan University on 04/23/15 For personal use only.
University of Missouri – Cardiology, Columbia, MO, USA Abstract
Keywords
Atrial fibrillation (AF) is an increasingly common cardiac arrhythmia, currently affecting more than 5 million Americans. Management of patients with AF can be complex, with key strategies including selecting rhythm control versus heart rate control and reducing the patient’s risk of stroke or other systemic embolization. The American Heart Association, American College of Cardiology, and Heart Rhythm Society released 2014 Guideline for the Management of Patients with Atrial Fibrillation, which outlines several new recommendations with important clinical implications. Among these are a new recommendation to use the CHA2DS2-Vasc score for stroke risk assessment, rather than the previously advised CHADS2 score, expansion of anticoagulation options in selected patients, decreased emphasis on the role of aspirin, and an increased emphasis on the role of catheter ablation.
Atrial fibrillation, atrial flutter, anticoagulation, warfarin
Introduction Atrial fibrillation (AF) is an increasingly common cardiac arrhythmia, currently affecting more than 5 million Americans [1]. As the population ages, the incidence and prevalence of AF are expected to continue to rise [2]. Wellestablished risk factors associated with AF include increasing age, male gender, obesity, hypertension, left ventricular dysfunction, and alcohol consumption, among others [3]. Management of patients with AF can be complex. The rhythm may be paroxysmal, persistent, or permanent. Patients may be wholly asymptomatic or present with debilitating symptoms that affect quality of life [4]. The cornerstones of management center on selecting rhythm control versus heart rate control and reducing the patient’s risk of stroke or other systemic embolization. Recently released updated guidelines for management of patients with AF help in addressing and clarifying some key management issues [5]. Further, there are some important changes from the earlier 2006 guidelines [6] and some important differences from European guidelines. Although a comprehensive review of the updated guidelines is beyond the scope of this article, what follows will highlight some important changes in the guidelines that impact clinical practice.
How do we classify AF? Identification of patients with AF occurs in a variety of settings. The rhythm may be detected as an incidental finding
History Received 16 December 2014 Accepted 12 March 2015 Published online 27 March 2015
on an electrocardiogram obtained for another reason. Telemetry monitoring for hospital inpatients or patients presenting for surgery may reveal AF. AF may also be detected in patients with other monitoring devices, such as Holter monitors, event monitors, loop recorders, pacemakers, implantable cardiac defibrillators, or others. Still other patients may present urgently to clinic or the emergency department with symptomatic AF, embolic complication, or heart failure. The American Heart Association, American College of Cardiology, and Heart Rhythm Society 2014 guideline makes no mention of the duration of AF required to make a diagnosis; the diagnosis of AF requires only an electrocardiogram documenting the arrhythmia. Once the diagnosis is established, attention turns to classification. Because this arrhythmia presents in many different ways, over the years there have been many different terms used to describe and classify AF [7]. These include “acute” versus “chronic”, “lone AF”, “first-detected”, “self-terminating”, “recurrent”, “focal”, and many others. There continues to be a great deal of heterogeneity regarding definition and classification of AF, as exemplified by a recent survey of physicians who treat patients with this arrhythmia [8]. Clinical classification of types of AF can be useful in determining the treatment strategies. For example, a rhythm control strategy might be considered in a patient with paroxysmal or persistent AF; a rate control strategy is pursued in a patient with permanent AF. Although some have doubted the accuracy of the clinical classification of types of AF [9], the current guidelines simplify the classification and definitions
Correspondence: Greg Flaker, University of Missouri – Cardiology, one hospital Dr CE306, Columbia, MO 65212, USA. E-mail: [email protected] 2015 Informa UK Ltd.
2
R. Littrell & G. Flaker
Postgrad Med, 2015; Early Online:1–4
Table 1. Classification [5]. Term definition Paroxysmal AF Persistent AF Long-standing persistent AF Permanent AF
Non-valvular AF
AF that terminates spontaneously or with intervention within 7 days of onset Episodes may recur with variable frequency Continuous AF that is sustained >7 days Continuous AF of >12 months duration Permanent AF is used when there has been a joint decision by the patient and clinician to cease further attempts to restore and/or maintain sinus rhythm Acceptance of AF represents a therapeutic attitude on the part of the patient and clinician rather than an inherent pathophysiological attribute of the AF Acceptance of AF may change as symptoms, the efficacy of therapeutic interventions, and patient and clinician preferences evolve AF in the absence of rheumatic mitral stenosis, a mechanical or bioprosthetic heart valve, or mitral valve repair
Postgraduate Medicine Downloaded from informahealthcare.com by Kainan University on 04/23/15 For personal use only.
Abbreviation: AF = Atrial fibrillation.
for how we describe AF. The new classifications are based primarily on duration of episodes. If an episode of AF terminates (either spontaneously or with intervention) within 7 days of onset, it is considered paroxysmal. Persistent AF describes episodes that last >7 days. If the arrhythmia persists >12 months, it is considered long-standing persistent AF. The term “permanent AF” is used to describe patients for whom no further attempts at restoring or maintaining sinus rhythm will be made. Guideline authors do note that permanent AF patients may be reclassified as symptoms, treatments and their preferences evolve (Table 1). Non-valvular AF is frequently misinterpreted by clinicians from a definition perspective. In clinical trials non-valvular AF included patients with significant valve disease but excluded patients with clinically significant (moderate to severe) mitral stenosis or patients who required anticoagulation such as patients with prosthetic mechanical heart valves. The in-between cases are those with bioprosthetic valves or those with mitral valve repair. Some of these patients were included in the clinical trials but there is little in the way of guidelines in these patients. Until additional data are provided, it might be best to use warfarin in these patients.
Who needs anticoagulation? One of the most important questions addressed by physicians caring for patients with AF is to decide for whom to recommend oral anticoagulation. Anticoagulation is recommended based on the individual patient’s risk of stroke or other systemic embolism. This risk is determined based on risk factors once AF is present, and without regard to whether it is paroxysmal, persistent, or permanent. The 2014 guidelines recommend (as a class I recommendation) using the CHA2DS2-Vasc score for stroke risk assessment, rather than the CHADS2 score recommended in 2006 guidelines, for patients with non-valvular AF [5]. The CHADS2 score [10] assigns 1 point each for the presence of congestive heart failure, hypertension, age ‡75 years, and diabetes mellitus and assigns 2 points for history of stroke or transient ischemic attack. Anticoagulation with warfarin is recommended for a CHADS2 score of ‡2, and either warfarin or aspirin should be considered with a CHADS2 score of 1. Aspirin is recommended for a CHADS2 score of 0. The CHA2DS2-Vasc [11] score is a newer model that adds other risk factors including female gender, age 65–74 years,
and presence of vascular disease (Table 2). There is also greater importance placed on age ‡75 years, given the increased risk of stroke or other systemic embolism associated with aging. A score of ‡2 is considered high risk, and anticoagulation is recommended for these patients. Anticoagulation should be considered for patients with a CHA2DS2Vasc score of 1, who are considered to be at intermediate risk. No anticoagulation is recommended for patients with a CHA2DS2-Vasc score of 0, who are considered to be at low risk. Updated 2012 European Society of Cardiology (ESC) guidelines similarly recommend anticoagulation for patients with a CHA2DS2-Vasc score of ‡2, but also recommend anticoagulation in patients with a CHA2DS2-Vasc score of 1 after assessment of bleeding risk and patient preferences [12]. The Canadian Cardiovascular Society guidelines for the management of AF, updated in 2014, also recommend an algorithm based on CHADS2 risk factors for determining which patients benefit from oral anticoagulation. In contrast to ESC guidelines, Canadian guidelines do not consider female sex or vascular disease alone as sufficient to recommend oral anticoagulant therapy. Canadian guidelines do, however, recommend oral anticoagulation for patients aged ‡65 years. Canadian guidelines favor novel oral anticoagulants over warfarin in patients with non-valvular AF [13]. Under the CHA2DS2-Vasc scoring system, fewer patients are considered intermediate risk, and therefore anticoagulation is recommended more frequently than when using the CHADS2 score.
Should aspirin be recommended for prevention of thromboembolism? In the 2006 guideline, aspirin was recommended for patients with CHADS2 score of 0, and aspirin or warfarin was Table 2. CHA2DS2-Vasc score. Risk factor Congestive heart failure/left ventricular dysfunction Hypertension Age ‡75 years Diabetes mellitus Stroke/transient ischemic attack/thromboembolism Vascular disease (prior myocardial infarction, peripheral artery disease, or aortic plaque) Age 65–74 years Sex category (i.e. female gender)
Score 1 1 2 1 2 1 1 1
DOI: 10.1080/00325481.2015.1029863
Guideline for the management of patients with atrial fibrillation
Postgraduate Medicine Downloaded from informahealthcare.com by Kainan University on 04/23/15 For personal use only.
recommended for patients with CHADS2 score of 1. Aspirin 81–325 mg/day was also recommended for patients who could not take warfarin [14]. In the new guideline, aspirin has a reduced role. For patients with a CHA2DS2-Vasc score of 0, no anticoagulation is recommended. For patients with a CHA2DS2-Vasc score of 1, it is reasonable to consider anticoagulation, aspirin, or no anticoagulation. Newer European guidelines also have a reduced role for aspirin. According to 2012 ESC guidelines, aspirin should only be considered in patients who refuse any oral anticoagulant, or who cannot tolerate anticoagulants for reasons other than bleeding [12].
Which anticoagulant should be prescribed? In patients for whom anticoagulation is recommended, the new guideline offers options beyond warfarin. Options include warfarin (with goal international normalized ratio of 2.0 to 3.0) or a newer agent including dabigatran, rivaroxaban, or apixaban. The use of a newer agent is recommended for patients who cannot maintain therapeutic levels of warfarin. As per the guideline, warfarin remains the agent of choice in patients with end-stage renal disease (creatinine clearance 95 ml/minute. Warfarin also remains the anticoagulant of choice in patients with prosthetic heart valves. The European guideline expresses a stronger preference for novel agents, stating that the novel oral anticoagulants available to date have all shown noninferiority to warfarin, with better safety; thus, novel oral anticoagulants are recommended as “broadly preferable to vitamin K antagonists in the vast majority of patients with non-valvular atrial fibrillation when used as studied in the clinical trials performed so far [11]”. Canadian guidelines similarly recommend novel oral anticoagulants over warfarin in patients with nonvalvular AF. In patients with AF who require percutaneous coronary intervention, bare metal stents may be considered to minimize the duration of dual antiplatelet therapy (class IIb). In patients who receive stents, it may be reasonable to continue clopidogrel and anticoagulation, without the use of aspirin (also class IIb). Bleeding risk is always a concern when prescribing an anticoagulant. The 2014 guideline does not emphasize assessment of bleeding risk. The 2012 ESC guideline, on the other hand, recommends using a scoring system to evaluate bleeding risk and adjusting the dose if bleeding risk is high.
Rhythm control or rate control? Both rate control and rhythm control strategies offer the opportunity to improve symptoms and quality of life, and the decision for which strategy to pursue is made between
3
the physician and each individual patient. Both ESC and Canadian guidelines outline recommendations for pursuing rhythm control when needed to improve symptoms and quality of life. The 2014 guideline by contrast offers less direction regarding when to pursue a rhythm control strategy. In patients for whom a rhythm control strategy is selected, cardioversion is a recommended strategy to restore sinus rhythm. If unsuccessful, it is reasonable to adjust electrode location or pressure and reattempt, or to try again after administering an antiarrhythmic medication. It may also be reasonable to perform repeated cardioversion if the patient can maintain sinus rhythm “for a clinically meaningful period” between procedures. Restoration of sinus rhythm does not, however, obviate the need for anticoagulation. All patients undergoing cardioversion should be anticoagulated for at least 4 weeks after cardioversion, with one exception. The 2014 guideline states that patients who have AF or atrial flutter for
