Previously published report, no 2005-02 »
This document updates a report published by SBU Alert in 2005.
Atrial fibrillation is an abnormal irregular heart rhythm (atrial tachyarrhythmia) characterized by a rapid and uncoordinated activation of the upper chambers of the heart (atria), leading to an irregular and unsynchronized activation of the lower chambers (ventricles). Atrial fibrillation is the most common tachyarrhythmia and is often associated with an impaired heart function and an increased risk for embolic stroke.
Although many patients may benefit from antiarrhythmic drug treatment, catheter ablation is a treatment option for patients with severe symptoms who do not respond to or cannot tolerate antiarrhythmic drugs. Using a special ablation catheter, heat energy can be applied to tissue around the pulmonary veins (pulmonary vein isolation) and, in some cases, to certain areas in the left atrium.
Pulmonary vein isolation (electrical isolation of the pulmonary veins) is an invasive procedure during which an ablation catheter is used to apply heat energy around the pulmonary veins. It is currently the standard method shown to be most effective against recurrences of paroxysmal atrial fibrillation. The risk of recurrence is higher for patients with persistent atrial fibrillation, despite adjunct therapies. New ablation methods are being developed.
The experience with atrial fibrillation ablation therapy in patients above 70 years of age is relatively limited. The complication rate appears to be higher in this age group. Hence, the method is primarily recommended for people who are below 70 years of age and without marked enlargement of the left atrium. If ablation therapy is offered primarily to patients 70 years of age and younger, the potential target population for the method is estimated to be approximately 2 000 patients per year in Sweden.
Studies that have compared pharmacotherapy with ablation therapy are of medium or high quality, but offer limited information about long-term effects.
Findings from several randomized trials show that symptomatic atrial fibrillation occurs less often in patients that have undergone catheter ablation therapy than in those treated with antiarrhythmic drugs. Quality of life is more favourably affected by ablation than by drugs.
Treatment results are better among patients with paroxysmal atrial fibrillation than among those with persistent atrial fibrillation.
Serious complications occur in 4–5 percent of patients treated by catheter ablation. The most serious complication following ablation in the posterior wall of the left atrium involves development of a fistula between the left atrium and the esophagus. Other serious complications are cardiac tamponade, thromboembolism, pulmonary vein stenosis, and permanent damage to structures adjacent to the left atrium, eg, the phrenic nerve.
Catheter ablation therapy can markedly improve health and quality of life in patients with pronounced symptoms and who cannot be treated effectively with drugs. The procedure carries some risk for serious complications. Hence, it is important that patients who are candidates for treatment receive comprehensive and objective information concerning the risks and the expected benefits of the method.
The cost of the procedure is estimated at approximately 85 000 Swedish kronor (SEK), including examinations and 2 to 4 days of hospitalization. To achieve its intended effects, the procedure may need to be repeated. Economic analyses suggest that catheter ablation can be a cost-effective treatment method in patients where antiarrhythmic agents have not yielded the desired effects. However, there is some uncertainty concerning the extent to which the positive effects on patients’ quality of life continue over the long-term.
* Criteria for evidence grading SBU’s conclusionsEvidence grade 1 – Strong scientific evidence. The conclusion is corroborated by at least two independent studies with high quality, or a good systematic overview.Evidence grade 2 – Moderately strong scientific evidence. The conclusion is corroborated by one study with high quality, and at least two studies with medium quality.Evidence grade 3 – Limited scientific evidence. The conclusion is corroborated by at least two studies with medium quality.Insufficient scientific evidence – No conclusions can be drawn when there are not any studies that meet the criteria for quality.Contradictory scientific evidence – No conclusions can be drawn when there are studies with the same quality whose findings contradict each other.
SBU Alert is a service provided by SBU in collaboration with the Medical Products Agency, the National Board of Health and Welfare, and the Swedish Association of Local Authorities and Regions.