On March 28, 2014, the American Heart Association (AHA), the American College of Cardiology (ACC) and the Heart Rhythm Society (HRS) jointly released the 2014 Guidelines for the Treatment of Patients with Atrial Fibrillation, replacing the 2006 edition of the guidelines and the two 2011 updates, and reflecting portions of the 2012 European Society of Cardiology (ESC) guidelines for atrial fibrillation (AF) The new guidelines review the 2006 guidelines and the two 2011 updates. The new guideline reviews the relevant literature from 2006 to February 2014 and summarizes the latest consensus of clinical experts in the field of AF treatment, including adult cardiology, electrophysiology, cardiothoracic surgery, and heart failure. The new version of the guideline mainly includes the following 7 aspects.
I. General guideline
The aim is to develop treatment plans that meet the needs of the majority of patients in most situations, with the final decision resting with the physician and the patient, and with full consideration of the patient’s clinical situation. The inclusion of shared decision making as a Category I recommendation is already a great advancement in the guidelines. The new guidelines better reflect the famous words of Professor Krumholz of Yale University: “The highest quality of care is when patients choose the option that best fits their values, preferences, and goals, and we need to ensure that their decisions are not motivated by ignorance or fear.”
II. Definition of non-valvular atrial fibrillation
This guideline defines nonvalvular atrial fibrillation as atrial fibrillation occurring in patients without rheumatic mitral stenosis, mechanical valves, bioprosthetic valves, or mitral valve repair. Obviously, this is a very broad definition, according to which any mitral regurgitation without surgical or interventional treatment, all aortic, pulmonary, and tricuspid valve lesions, and other types of atrial fibrillation fall under the category of nonvalvular atrial fibrillation.
Such a classification is based primarily on the different risk of embolism due to different valvular lesions, rather than a classification based solely on anatomic or functional abnormalities of the valve. Embolic events are significantly more common in rheumatic mitral valve lesions (especially mitral stenosis) than in other forms of valve disease (e.g., aortic stenosis or insufficiency), and the incidence of embolic events is higher in mitral stenosis than in mitral valve insufficiency. Notably, many embolic events occur in patients with mild mitral valve disease or early in the onset of clinical symptoms.
Mitral balloon angioplasty does not reduce the risk of thromboembolism, and postoperative anticoagulation therapy is still indicated. All patients with mechanical valves receive long-term (permanent) oral antithrombotic therapy. There is a risk of thromboembolism during the first 3 months after bioprosthetic valve surgery, especially in the mitral site, and therefore bioprosthetic valves are anticoagulated for 3 months after surgery, followed by long-term aspirin. After aortic bioprosthetic valve replacement, including transcatheter valve replacement, no anticoagulation is required and antiplatelet therapy is recommended.
According to the above classification, atrial fibrillation occurring in patients with rheumatic mitral stenosis, mechanical valves, bioprosthetic valves, or mitral valve repair, that is, patients who meet the definition of valvular atrial fibrillation, are at high risk for embolism and do not require further risk scoring for embolism. 2010 ESC guidelines for atrial fibrillation had indicated that patients with valvular atrial fibrillation were the main clinical risk factor for embolism and recommended anticoagulation for such patients, in contrast to the The new US guidelines for valvular atrial fibrillation are fully consistent.
III. Special Emphasis on Atrial Flutter
The incidence of typical atrial flutter (atrial flutter) (i.e., inferior vena cava-tricuspid annular isthmus-dependent atrial flutter) has increased with the increase in obesity, sleep apnea, atrial fibrillation drug use, and advanced age in the population. At the same time, advances in the field of left atrial catheter ablation have deepened the understanding of atypical atrial flutter.
Atrial fibrillation with “coarse atrial waves” is easily misdiagnosed as atrial flutter. This is a common mistake in clinical practice.
In addition, the success rate of ablation of typical atrial flutter is high, while that of ablation of atypical atrial flutter is low, so it is significant to identify these two types of atrial flutter.
IV. Antithrombotic drug therapy
The new guidelines incorporate new clinical research evidence, a comprehensive review of the literature, new treatment strategies and new drugs, and suggest that antithrombotic therapy should begin with a comprehensive assessment of stroke and bleeding risk and patient attitudes, followed by individualized treatment decisions by the physician and patient. The new version of the guideline has 7 changes in antithrombotic therapy as follows.
The 2012 ESC guidelines recommend the use of the CHA, DS, -VASe score to assess stroke risk in patients with atrial fibrillation, whereas the 9th edition of the American College of Chest Physicians (ACCP) guidelines of the same year still promote the CHADS score, which helps to identify patients at high risk of embolism. The limitation is that it does not identify patients who are truly at low risk.
Subsequent studies have demonstrated that the CHA2DS2-VASc improves the assessment of low- and intermediate-risk patients compared to the CHADS and helps to identify patients at low risk for true embolism. However, the confidence interval for the CHA2DS2 -VASc score is wide, the predictive power is only moderate, the C-statistic value of the investigator’s working (ROC) curve is <0.7, the embolic risk scoring system needs further improvement, and no single scoring system can cover all risk factors for embolism. Physicians are still required to make a comprehensive assessment of various clinical conditions and make a comprehensive judgment. < p="">
2. Bleeding risk assessment: When the HAS-BLED score is used for the assessment of bleeding risk, it should avoid equating bleeding risk factors with contraindications to anticoagulation therapy. While the guidelines recognize the status of this type of scoring system as a potential tool, they also state that patients should not be excluded from anticoagulation therapy based on these scores alone. People at high risk for bleeding are often also at high risk for embolism, and anticoagulation therapy still increases the net benefit for most patients.
3. Antithrombotic treatment strategy: The guidelines comprehensively recommend three new oral anticoagulants, weakening antiplatelet therapy and elevating the status of anticoagulation. This new version of the guideline proposes that anticoagulants may be used without anticoagulation, as well as aspirin (class IIh recommendation). The purpose of this is to have enough space to choose according to the patient’s situation, whereas the ESC guidelines only recommend the application of anticoagulants. In addition, the new guidelines emphasize that controlling other risk factors including hypertension and hyperlipidemia can significantly reduce the risk of stroke.
4. Anticoagulation before rhythm: There are differences between the European and American guidelines for anticoagulation in patients with atrial fibrillation who have been in rhythm for <48 h. The 2012 ESC guidelines recommend that all patients should be anticoagulated before rhythm resumption, either with heparin or low molecular weight heparin. This new edition of the guideline recommends that anticoagulation before resuscitation in patients at high risk of embolism should include new oral anticoagulants (Class I recommendation) in addition to heparin or low-molecular-weight heparin.
For patients at low risk of embolism, heparin or low-molecular-weight heparin or new oral anticoagulants can be used before resuscitation, or no anticoagulant can be used (Class IIb recommendation). The new oral anticoagulants are recommended for the first time in the new edition of the guidelines for acute anticoagulation because of their rapid onset of action and rapid anticoagulant effect. Although it has not been evaluated in the acute phase reentry population, it has also been recommended by the new edition of the guideline from the extrapolation of pharmacokinetic and pharmacodynamic effects.
5. Warfarin and new oral anticoagulants: The recommendations of the guideline can have a significant impact on the application of the drug, so the recommendations for new drugs should strive to be fair and well-documented. The new version of the guideline does not use the term “better than” or tend to recommend a certain drug for the old anticoagulant warfarin and new oral anticoagulants, but points out the indications, contraindications and expectations of various drugs.
The choice of antithrombotic drug should take into account the risk of stroke, cost, tolerability, patient preference, potential drug-drug interactions, and other clinical characteristics, including the time that the patient’s international normalized ratio (INR) is at the target value while receiving warfarin therapy. If a patient receiving warfarin has unstable INR control a switch to a new oral anticoagulant should be considered. The ESC guidelines recommend that new oral anticoagulants be preferred based on clinical studies showing that their antithrombotic efficacy is not inferior or superior to warfarin and that the risk of intracranial hemorrhage is reduced.
6. Dabigatran should not be used in patients with mechanical valve replacement: According to the results of the latest RE-ALIGN study, dabigatran should not be used in patients with mechanical valve replacement. 252 patients with aortic and or mitral mechanical valve replacement were enrolled in the RE-ALICN study and randomized to compare the efficacy and safety of dabigatran with warfarin, resulting in higher embolism and bleeding in the dabigatran group than in the control group. The study was stopped early.
The reasons for this may be related to the complicated situation in the early postoperative period, including inflammatory activation, platelet activation, and complicated coagulation mechanism due to the massive production of tissue factor, and also may be related to the combined medication, drug absorption, and many aggressive elements of liver and kidney function affecting the anticoagulation effect. Therefore, the traditional old drug warfarin is still irreplaceable in the high-risk stage of early postoperative thrombosis and highly individualized antithrombotic treatment period.
7. anticoagulation recommendations in special cases: oral anticoagulation plus clopidogrel is recommended in patients with atrial fibrillation with a CHA2DS2-VASc score of 2 or more after coronary revascularization, and coadministration of aspirin is not recommended (class IIb recommendation). the WOESrr study showed that the combination of warfarin and clopidogrel did not result in more embolic events than warfarin combined with clopidogrel and aspirin, and the risk of bleeding was less than The latter is reduced, and warfarin anticoagulation is recommended in patients with acute coronary syndrome combined with high-risk atrial fibrillation, unless contraindicated. Because of the lack of evidence, new oral anticoagulants are not recommended.
In patients with hypertrophic cardiomyopathy with atrial fibrillation, hypertrophic cardiomyopathy has a significantly increased risk of embolism compared with nonhypertrophic cardiomyopathy, and anticoagulation should be used in all cases without CHA2DS2-VASc score (Class I recommendation). In patients undergoing percutaneous coronary intervention, discontinuation of anticoagulation is still recommended to reduce the risk of bleeding at the puncture site, although preoperative nonstop anticoagulation is described (class IIb recommendation).
V. Non-pharmacologic approaches to embolism prevention
The new version of the guideline introduces percutaneous left atrial ear occlusion therapy, but no recommendation is given and it is still in the observation phase. Simultaneous resection of the left atrial ear for thrombosis prevention during surgery is a Class IIb recommendation.
VI. Rhythm control
The new version of the guideline does not make new recommendations or significant changes, and does not make recommendations for unmarketed antiarrhythmic drugs such as Vinacaran as aggressively as the ESC guideline does. The new version of the guidelines recommends treating the sudden or reversible cause of the disease before initiating antiarrhythmic drug therapy.
For the selection of antiarrhythmic drugs, the new edition of the guidelines also emphasizes that safety should be considered first, but there are still some differences in the drug recommendation levels from the ESC guidelines Ibutilide remains a Class IA recommendation in this new edition of the guidelines, while the ESC guidelines have been downgraded to a Class IIb recommendation due to its adverse effects in tip-twisting ventricular tachycardia. Amiodarone is a Class IIa recommendation in this new edition of the guideline, while the ESC guideline considers that although the rate of atrial fibrillation reversal is not better than other antiarrhythmic drugs, the safety of intravenous application of amiodarone to reversal of atrial fibrillation in the acute phase is good, so it is a Class I recommendation.
In addition, electrical cardioversion is still recommended for the management of preexcitation with atrial fibrillation. The recommendations for amiodarone in pharmacotherapy are significantly different from the ESC guidelines. This new edition of the guideline defines intravenous amiodarone in preexcited atrial fibrillation as a Class III recommendation based on case reports in the literature that amiodarone can increase ventricular rate and induce ventricular fibrillation, whereas the ESC guideline is a Class IC recommendation.
After conversion of atrial fibrillation to permanent atrial fibrillation, antiarrhythmic drugs, including dronedarone, cannot be continued for ventricular rate control (Class III recommendation). Dronedarone should not be used in patients with New York Heart Association class III and IV atrial fibrillation or in patients who have had an episode of decompensated heart failure within 4 weeks (Class III recommendation). The recommendations of the European and American guidelines are consistent.
For radiofrequency ablation of atrial fibrillation, it can be the starting treatment after weighing the risks and efficacy of drug therapy (Class IIa recommendation). Overall, however, this new edition of the guidelines does not appear to be more groundbreaking than the ESC 2012 guidelines.
VII. Ventricular rate control
Although the randomized trial (RACE-II) showed that heart rate control of less than 110 beats/min in patients with persistent atrial fibrillation was as effective as strict control of less than 80 beats/min, this new guideline suggests that the limitations of the RACE-II trial should be noted and that the results may not be applicable to a wider range of patients with atrial fibrillation. The new guideline favors strict control of heart rate less than 80 beats per minute (Class IIa recommendation).
The new version of the guideline recommends caution in the use of digoxin for ventricular rate control. The guideline reiterates the pharmacologic effects of digoxin and reviews the results of recent meta-analyses suggesting that digoxin may be harmful and that its use requires attention to the therapeutic window.
In summary, this new guideline has much to offer that warrants detailed reading and refinement, and its contents are of general guidance, but not everything is a universal guideline; it is, after all, an ACC/AHA/HRS guideline, based on practice in the North American population. This new edition of the guideline does not describe intravenous propafenone and recommends the use of Vinacaran for the conversion of atrial fibrillation, whereas dofetilide is recommended for the maintenance of sinus rhythm. These are due to the peculiarities in the availability of drugs in the United States. It is more important to study this new edition of the guideline, taking into account our specific situation and our successful experience, to apply various measures correctly according to the condition of different patients.