The committee agreed that the cost-effectiveness analyses of different types of ablation in paroxysmal atrial fibrillation could also be applied to this population. The committee emphasised the importance of discussing the risks and benefits of catheter ablation with the person, in particular the risk of adverse events. The discussion should also include that, in the experience of the committee, the effects of ablation may not be long term. How the recommendations might affect practice The committee noted that the recommendations are likely to reinforce current practice. Ablation is carried out in a relatively restricted population (approximately 1% to 2% of all people with atrial fibrillation currently have ablation) and is usually reserved for people in whom antiarrhythmic drugs have failed. The recommendation is likely to lead to a change in the types of ablation offered, with more people receiving radiofrequency point-by-point ablation and fewer having other catheter ablation techniques. Return to recommendations Preventing recurrence after ablation Why the committee made the recommendations Most of the evidence on preventing recurrence after ablation was for amiodarone. The evidence suggested that amiodarone may reduce recurrence of atrial fibrillation after ablation. However, there was evidence of an increased risk of hospitalisation and the committee noted the known side effects of amiodarone, which, although rare, can be severe and life-threatening. There was a lack of evidence for other antiarrhythmic drugs and there were no comparisons between different antiarrhythmic drugs. Therefore, the committee agreed that there was too much uncertainty to recommend one specific antiarrhythmic drug over others. In addition, the studies often made no distinction between people who had been on antiarrhythmic drugs up to ablation and those who had not. There is variation in current practice on whether people who were not previously taking antiarrhythmic drugs should start them after ablation to reduce recurrence. However, the evidence did not support making separate recommendations to clarify this. The committee decided that antiarrhythmic drug treatment should be considered after ablation, but only after discussion with the person, taking into account their preferences for treatment and the potential individual risks and benefits. In particular, the committee noted that people should fully understand the potential adverse events associated with these drugs. While there is some variation, the committee agreed that good current practice is for patients taking antiarrhythmic drugs up to ablation to continue them for 3 months after ablation and reassess the need for drug treatment after this time. How the recommendations might affect practice There is some variation in current practice. Practice is likely to change in some centres both in prescribing and in the need for a more formal reassessment of treatment at 3 months. The impact on use of antiarrhythmic drugs is difficult to predict, but there may be an increase from current levels. Increased resources may be needed for reassessment, but it is anticipated that this could be performed at routine follow-up appointments with a cardiologist. Return to recommendations Rate and rhythm control for people presenting acutely Why the committee made the recommendation The committee agreed that the evidence was too limited in quality and quantity to be able to specify a preferred rate-control drug for acute atrial fibrillation. Although there was some evidence that amiodarone was better than digoxin for rate control, the committee had concerns about the quality of the evidence and the short timeframe used in 1 study, which it agreed could disadvantage digoxin. In addition, there was limited evidence available for morbidity and adverse events for this comparison and no evidence identified for other drug classes. The committee highlighted that the existing recommendations gave no guidance on acute atrial fibrillation with acute decompensated heart failure. Using their expertise and experience the committee agreed that advice on the use of beta-blockers and rate- limiting calcium-channel blockers should be included because they can lead to further deterioration in people with pulmonary oedema caused by heart failure. How the recommendation might affect practice The recommendations do not constitute a change in practice, and so are unlikely to have a resource impact. Return to recommendations Preventing postoperative atrial fibrillation Why the committee made the recommendations The committee noted that the most recent studies reviewed showed no benefit from statins in reducing atrial fibrillation after cardiothoracic surgery. This contrasted with analysis of the evidence overall, which showed a small but definite benefit from statins. The committee agreed that the evidence of no effect in the newer studies was important, because these studies were larger and of higher quality than the older studies included in the analysis. Although the newer studies suggested that statins did not affect the short-term risk of stroke, they did suggest a greater risk of mortality in the peri-operative period compared with placebo treatment or usual care. The committee agreed that although the additional risk of death was probably small, it was important, especially alongside the lack of convincing evidence of benefit. For these reasons, the committee decided that statins should not be given to prevent atrial fibrillation after cardiothoracic surgery. However, the committee wanted to highlight that statins have an important role in preventing cardiovascular events other than atrial fibrillation and that people already taking statins for other reasons should continue to do so. How the recommendations might affect practice The committee agreed that the recommendation would not constitute a change in practice, and that there would not be a resource impact on the NHS. Return to recommendations Managing atrial fibrillation after cardiothoracic surgery Why the committee made the recommendations The evidence on managing postoperative atrial fibrillation after cardiothoracic surgery in people without pre-existing atrial fibrillation was limited many of the studies reviewed were old and included small numbers of participants. There were few studies comparing drug classes, and the committee agreed that they could not recommend a particular class of drugs based on such limited evidence. One larger study comparing mixed rate control and rhythm control with a potassium-channel blocker (amiodarone) with or without rate control suggested little difference between the 2 groups. Based on this evidence and their experience, the committee decided that rhythm control could be considered but that the evidence no longer supported the stronger recommendation included in the 2014 guideline. The committee noted that postoperative atrial fibrillation often resolves naturally, meaning that rate control rather than rhythm control may be a suitable option for some people. Reducing the emphasis on rhythm-control strategies will allow rate-control strategies to be considered if appropriate for the person. The committee were also aware of the risk of adverse events if amiodarone, a rhythm control drug, is taken long-term. They highlighted that if a rhythm-control strategy is chosen, the need for rhythm control drugs should be reassessed at approximately 6 weeks, in line with current practice, and they should not be continued automatically for long periods of time. The committee agreed that 6 weeks is an appropriate time point to assess the person's recovery, including for example prosthetic valve function, and to check if sinus rhythm has been restored. The committee did not make a separate recommendation for people with pre-existing atrial fibrillation because of a lack of evidence. The committee noted that most people undergoing mitral valve surgery with pre-existing atrial fibrillation would undergo left atrial surgery to treat atrial fibrillation at the same time. How the recommendations might affect practice Rhythm control for the treatment of new-onset atrial fibrillation after cardiothoracic surgery is current practice and amiodarone is most commonly used. This can still be considered, but there may be a reduction in the use of rhythm control in this population and an increase in the use of rate-control drugs instead. Return to recommendations Stopping anticoagulation Why the committee made the recommendations There was limited evidence on whether to continue anticoagulation or to stop it and switch to aspirin after successful treatment of atrial fibrillation by catheter ablation. The committee agreed that the evidence was insufficient and that there was too much uncertainty in the results to make a recommendation based on the evidence. The committee therefore developed research recommendations on stopping anticoagulation after ablation and stopping anticoagulation after resolution of postoperative atrial fibrillation to encourage further research. The committee was concerned about the potential withdrawal of anticoagulation in people who had not had ablation or cardiac surgery for atrial fibrillation, but in whom sinus rhythm is now present and atrial fibrillation is no longer detectable. In particular, the committee noted that paroxysmal atrial fibrillation is not always detectable. Based on their experience, the committee made a consensus-based recommendation to ensure that decisions about stopping anticoagulation in this population are based on formal risk assessment of stroke and bleeding risks and patient preference. How the recommendations might affect practice The committee felt that the recommendation would not constitute a change in practice, and that there would not be a resource impact on the NHS. Return to recommendations Context Atrial fibrillation is the most common heart rhythm disorder (affecting approximately 2% of the adult population), and estimates suggest its prevalence is increasing. Atrial fibrillation causes palpitations and breathlessness in many people but it may be silent and undetected. If left untreated it is a significant risk factor for stroke and other morbidities: it is estimated that it is responsible for approximately 20% of all strokes and is associated with increased mortality. Men are more commonly affected than women and the prevalence increases with age and in underlying heart disease, diabetes, obesity and hypertension. Atrial fibrillation is typically detected as an irregular pulse or an irregular rhythm on an electrocardiogram (ECG). This may be an incidental finding or may arise while investigating symptoms suggestive of the disease. Because atrial fibrillation can be intermittent, detection and diagnosis may be challenging. The aim of treatment is to prevent complications, particularly stroke, and alleviate symptoms. Drug treatments include anticoagulants to reduce the risk of stroke and antiarrhythmics to restore or maintain the normal heart rhythm or to slow the heart rate in people who remain in atrial fibrillation. Non-pharmacological management includes electrical cardioversion, which may be used to 'shock' the heart back to its normal rhythm, and catheter or surgical ablation to create lesions to stop the triggers that cause atrial fibrillation. These procedures can markedly reduce the symptom burden when drug therapy is ineffective or not tolerated. This update focuses on areas of new evidence and changing practice since the 2014 NICE guideline. These include methods of identifying atrial fibrillation; assessing stroke and bleeding risk; antithrombotic agents; ablation strategies; preventing recurrence; and preventing and managing postoperative atrial fibrillation. This guideline update includes recommendations on these specific issues. The recommendations apply to adults (18 years or older) with atrial fibrillation, including paroxysmal (recurrent), persistent and permanent atrial fibrillation, and atrial flutter. They do not apply to people with congenital heart disease precipitating atrial fibrillation. Finding more information and committee details To find NICE guidance on related topics, including guidance in development, see the NICE webpage on heart rhythm conditions. For full details of the evidence and the guideline committee's discussions, see the evidence reviews. You can also find information about how the guideline was developed, including details of the committee. NICE has produced tools and resources to help you put this guideline into practice. For general help and advice on putting our guidelines into practice, see resources to help you put NICE guidance into practice. Update information 30 June 2021: We further corrected recommendation 1.2.2 on using the ORBIT score to assess bleeding risk to reinstate the link to the previous calculation tool, which was amended in error on 10 June. The tool includes the full criteria, including options for reduced haemoglobin and reduced haematocrit which are available once the patient's sex has been selected. 10 June 2021: We amended recommendation 1.2.2 on using the ORBIT score to assess bleeding risk so that it links to a calculation tool that includes the full list of criteria, including reduced haemoglobin, reduced haematocrit and history of anaemia. We deleted a paragraph of text from the rationale and impact section for recommendation 1.8.3 that was included incorrectly. April 2021: We have reviewed the evidence and made new recommendations on diagnosis and assessment, assessment of stroke and bleeding risks, preventing stroke, rate and rhythm control, preventing recurrence, and preventing and managing postoperative atrial fibrillation. These recommendations are marked [2021]. Recommendations marked [2014] and [2006] last had an evidence review in 2014 and 2006 respectively. In some cases, minor changes have been made to the wording for clarity and to bring the language and style up to date, without changing the meaning. Minor changes since publication January 2022: Minor changes to redirect NICE Pathways links. October 2021: We added a link to NICE's shared decision making guideline in recommendation 1.4.2. Accreditation