NIHR DC Discover

NIHR Signal Rhythm control drugs after catheter ablation for atrial fibrillation give short-term but not long term benefits

Published on 27 September 2016

doi: 10.3310/signal-000307

When treating atrial fibrillation, short-term use of rhythm control drugs after catheter ablation reduced the risk of abnormal heart rhythms in the three months after the procedure. They were of no benefit in preventing recurrence of atrial fibrillation in the longer term.

Atrial fibrillation is a common abnormal heart rhythm that carries a high risk of stroke. Catheter ablation can be used to destroy the electrical pathways in the heart muscle that cause the abnormal rhythm, but recurrence is common.

Several factors could influence the likelihood of abnormal rhythms returning after catheter ablation. These include the duration and type of atrial fibrillation and associated medical conditions. Such things could influence practitioners’ decision to give further rhythm control treatment.

In the absence of a standard approach further study may be needed to inform the best treatment strategy.

Share your views on the research.

Why was this study needed?

Atrial fibrillation is a common abnormal heart rhythm that affects around 1 in 10 people over the age of 65. Around 800,000 people in the UK are known to have the condition, and there are thought to be another 250,000 undiagnosed cases. Treating atrial fibrillation and managing its complications is estimated to cost the NHS around £205,000,000 per year. The main complication is stroke, as the irregular heartbeats can lead to blood clots developing.

Catheter ablation can be an effective treatment option for some people. This involves putting thin tubes into a vein which are guided to the area in the heart causing the abnormal heartbeats. Energy is then sent to the heart to destroy the area.

However, catheter ablation can cause inflammation resulting in recurring abnormal heart rhythms.

Rhythm control drugs (antiarrhythmics) are thought to effectively reduce this side effect and are commonly used by doctors. However, there is uncertainty around how effective these are.

What did this study do?

This systematic review and meta-analysis analysed data from six randomised controlled trials, with a total of 2,764 patients. It evaluated the effectiveness of rhythm control drugs after catheter ablation compared with inactive placebo or no treatment. The main outcomes of interest were early recurrence of abnormal rapid heart rhythms (within the first three months), or later recurrence of atrial fibrillation.

All studies included patients with longstanding atrial fibrillation. Five studies included both patients with persistent atrial fibrillation and those with paroxysmal atrial fibrillation. One study included only patients with paroxysmal atrial fibrillation.

The greatest risk of bias was uncertainty over whether patient characteristics may have influenced group allocation, and that participants and outcome assessors may have been aware of treatment given. One trial contributed three-quarters of all patients in the review.

What did it find?

  • Rhythm control drugs reduced the risk of early recurrence of abnormal rapid heart rhythms. The recurrence rate was 39.5% in the drug group and 47.2% in the control group (pooled risk ratio [RR] 0.78, 95% confidence interval [CI] 0.62 to 0.98). There were, however, significant differences between the results of the individual trials suggesting this finding should be interpreted with some caution.
  • Rhythm control drugs had no effect on the likelihood of later recurrence of atrial fibrillation after three months, which was 32.5% in the drug group and 34.6% in the control group (RR 0.94, 95% CI 0.85 to 1.05). This was from pooled analysis of five trials, which did not differ in their results, increasing confidence in this finding.

What does current guidance say on this issue?

NICE guidelines published in 2014 recommend ablation of areas in the left upper heart chamber for people with persistent or paroxysmal atrial fibrillation if drug treatment is unsuitable or has failed to control symptoms. There is no specific guidance on use of rhythm control drugs following ablation.

What are the implications?

The review suggests that rhythm control drugs could reduce the likelihood of rapid, abnormal heart rhythms in the first few months after catheter ablation. However, they were ineffective at preventing late recurrence of atrial fibrillation.

This evaluation is heavily reliant on the results of a single trial. Patient characteristics, such as duration of atrial fibrillation and associated diseases, affect the chance of atrial fibrillation recurrence and will influence the doctor’s decision to treat.

Currently there is no standard approach to the short-term use of rhythm control drugs following catheter ablation.  More information on choice of agent and characteristics of patients most likely to benefit is needed to guide clinical management.

Citation and Funding

Xu B, Peng F, Tang W, et al. Short-term Antiarrhythmic Drugs After Catheter Ablation for Atrial Fibrillation A Meta-analysis of Randomized Controlled Trials. Ann Pharmacother. 2016;50(9):697-705.

The authors received no financial support for the research, authorship, and/or publication of this article.

Bibliography

BHF. Atrial Fibrillation. London: British Heart Foundation; 2016.

NICE. Atrial fibrillation: management. CG180. London: National Institute for Health and Care Excellence; 2014.

The Office of Health Economics. Estimating the direct costs of atrial fibrillation to the NHS in the constituent countries of the UK and at SHA level in England, 2008. November 2009, London.

Why was this study needed?

Atrial fibrillation is a common abnormal heart rhythm that affects around 1 in 10 people over the age of 65. Around 800,000 people in the UK are known to have the condition, and there are thought to be another 250,000 undiagnosed cases. Treating atrial fibrillation and managing its complications is estimated to cost the NHS around £205,000,000 per year. The main complication is stroke, as the irregular heartbeats can lead to blood clots developing.

Catheter ablation can be an effective treatment option for some people. This involves putting thin tubes into a vein which are guided to the area in the heart causing the abnormal heartbeats. Energy is then sent to the heart to destroy the area.

However, catheter ablation can cause inflammation resulting in recurring abnormal heart rhythms.

Rhythm control drugs (antiarrhythmics) are thought to effectively reduce this side effect and are commonly used by doctors. However, there is uncertainty around how effective these are.

What did this study do?

This systematic review and meta-analysis analysed data from six randomised controlled trials, with a total of 2,764 patients. It evaluated the effectiveness of rhythm control drugs after catheter ablation compared with inactive placebo or no treatment. The main outcomes of interest were early recurrence of abnormal rapid heart rhythms (within the first three months), or later recurrence of atrial fibrillation.

All studies included patients with longstanding atrial fibrillation. Five studies included both patients with persistent atrial fibrillation and those with paroxysmal atrial fibrillation. One study included only patients with paroxysmal atrial fibrillation.

The greatest risk of bias was uncertainty over whether patient characteristics may have influenced group allocation, and that participants and outcome assessors may have been aware of treatment given. One trial contributed three-quarters of all patients in the review.

What did it find?

  • Rhythm control drugs reduced the risk of early recurrence of abnormal rapid heart rhythms. The recurrence rate was 39.5% in the drug group and 47.2% in the control group (pooled risk ratio [RR] 0.78, 95% confidence interval [CI] 0.62 to 0.98). There were, however, significant differences between the results of the individual trials suggesting this finding should be interpreted with some caution.
  • Rhythm control drugs had no effect on the likelihood of later recurrence of atrial fibrillation after three months, which was 32.5% in the drug group and 34.6% in the control group (RR 0.94, 95% CI 0.85 to 1.05). This was from pooled analysis of five trials, which did not differ in their results, increasing confidence in this finding.

What does current guidance say on this issue?

NICE guidelines published in 2014 recommend ablation of areas in the left upper heart chamber for people with persistent or paroxysmal atrial fibrillation if drug treatment is unsuitable or has failed to control symptoms. There is no specific guidance on use of rhythm control drugs following ablation.

What are the implications?

The review suggests that rhythm control drugs could reduce the likelihood of rapid, abnormal heart rhythms in the first few months after catheter ablation. However, they were ineffective at preventing late recurrence of atrial fibrillation.

This evaluation is heavily reliant on the results of a single trial. Patient characteristics, such as duration of atrial fibrillation and associated diseases, affect the chance of atrial fibrillation recurrence and will influence the doctor’s decision to treat.

Currently there is no standard approach to the short-term use of rhythm control drugs following catheter ablation.  More information on choice of agent and characteristics of patients most likely to benefit is needed to guide clinical management.

Citation and Funding

Xu B, Peng F, Tang W, et al. Short-term Antiarrhythmic Drugs After Catheter Ablation for Atrial Fibrillation A Meta-analysis of Randomized Controlled Trials. Ann Pharmacother. 2016;50(9):697-705.

The authors received no financial support for the research, authorship, and/or publication of this article.

Bibliography

BHF. Atrial Fibrillation. London: British Heart Foundation; 2016.

NICE. Atrial fibrillation: management. CG180. London: National Institute for Health and Care Excellence; 2014.

The Office of Health Economics. Estimating the direct costs of atrial fibrillation to the NHS in the constituent countries of the UK and at SHA level in England, 2008. November 2009, London.

Short-term Antiarrhythmic Drugs After Catheter Ablation for Atrial Fibrillation: A Meta-analysis of Randomized Controlled Trials

Published on 19 June 2016

Xu, B.,Peng, F.,Tang, W.,Du, Y.,Guo, H.

Ann Pharmacother , 2016

BACKGROUND: The incidence of recurrent arrhythmia after catheter ablation (CA) for atrial fibrillation (AF) is unacceptable. Short-term antiarrhythmic drug (AAD) treatment following CA was presumed to be effective in reducing recurrent arrhythmia. OBJECTIVE: To fully evaluate the efficacy of short-term use of AADs following CA for AF in preventing recurrence of atrial tachyarrhythmias. METHODS: PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched up until May 1, 2016. We enrolled randomized controlled trials (RCTs) that evaluated the efficacy of short-term use of AADs following CA for AF in preventing early and/or late recurrence of atrial tachyarrhythmias. The statistical analyses were performed using Review Manager Version 5.3. RESULTS: Six RCTs were included in this analysis, involving a total of 2764 patients. The frequency of early recurrence of atrial tachyarrhythmias was 39.5% in the AAD group (556 of 1407) and 47.2% (640 of 1357) in the control group. The pooled risk ratio of the AAD group to the control group was 0.78 (95% CI = 0.62-0.98). Regarding late recurrence of AF (LRAF), the incidence in the AAD group and the control group was 32.5% (420 of 1293) and 34.6% (450 of 1300), respectively. No significant difference was identified between the 2 groups (relative risk = 0.94, 95% CI = 0.85-1.05). CONCLUSIONS: Short-term use of AADs following CA for AF reduced the incidence of early recurrent atrial tachyarrhythmias but did not prevent LRAF.

Expert commentary

This meta-analysis of randomised trials shows that short-term use of antiarrhythmic drugs following catheter ablation for atrial fibrillation reduced the incidence of early recurrent atrial tachyarrhythmias but did not prevent late recurrence. This is unsurprising since atrial fibrillation is not a ‘static’ arrhythmia, being increasingly more likely with ageing and the accumulation of risk factors (e.g. hypertension, heart failure, vascular disease, etc). Catheter ablation remains a useful option for symptomatic patients where antiarrhythmic drugs are ineffective or not tolerated. Long term prognosis (e.g. reduced mortality) is still unproven. The randomised trials are also modest in size and from selected patients in specialised centres.

Gregory YH Lip, Professor of Cardiovascular Medicine, University of Birmingham