NIHR Signal Continuous positive airway pressure treatment for obstructive sleep apnoea linked to fewer recurrences of heart rhythm abnormalities

Published on 2 February 2016

Treating a common sleep-related breathing condition almost halved the chance of recurrent atrial fibrillation (AF, see Definitions). However, most of the included studies were observational. This makes it difficult to rule out the possibility of bias in choosing which patients to treat and therefore reduces our confidence in the size of this effect. The breathing condition - obstructive sleep apnoea (see Definitions) - has often been found in association with AF.

This review aimed to see whether a recommended treatment for people with obstructive sleep apnoea, continuous positive airway pressure (CPAP, see Definitions) might reduce the risk of AF recurring in those with the condition.

The study did not address the cost implications of diagnosing or treating obstructive sleep apnoea, which could be high, particularly if considering screening people with sleep disordered breathing for AF. Neither did it look at the acceptability of wearing a CPAP device at night. Other reviews have found that some people find this treatment uncomfortable and don’t persist with it.

Further high quality evidence, economic analysis and service reorganisation are needed before this could enter common practice in the NHS.

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Why was this study needed?

Obstructive sleep apnoea is thought to affect up to 4% of middle-aged men and 2% of middle-aged women in the UK. The condition has been found in association with AF, the most common type of heart rhythm abnormality, which affects around 2% of people in the UK. Previous research has suggested that people with obstructive sleep apnoea are six times as likely to have AF as the general population, and those with AF are more than twice as likely to have obstructive sleep apnoea. The reasons for the link are incompletely understood.

It is thought that obstructive sleep apnoea is under-diagnosed in people with recurrent AF and that by improved detection the treatment of recurrent AF could be improved.

The aim of this review was to determine whether using CPAP to treat people with obstructive sleep apnoea and recurrent AF after a catheter ablation (see Definitions), could reduce the chances of AF recurring. AF recurs in about a quarter to two thirds of cases within 5 years of an ablation or cardioversion (see Definitions).

What did this study do?

This systematic review included eight studies including 1,247 adults with obstructive sleep apnoea who had been treated for AF by catheter ablation. Of these people 698 had used CPAP and 549 were non-users. The researchers compared risk of AF recurrence between the two groups of people.

The review met reporting standards and assessed quality of included studies using Cochrane guidelines. However, most of the studies included less than 200 participants, and only one of the eight studies was a randomised controlled trial (of low quality), the rest were cohort studies. Observational studies cannot provide such robust evidence as randomised controlled trials because patient characteristics may have influenced the decision to use CPAP or not, and may also influence risk of AF recurrence.

The review did not address patient preferences or experiences of using CPAP.

What did it find?

  • Across the eight studies, AF recurred in 18% of those who used CPAP and 37% of those who did not. This meant that CPAP was associated with 44% reduced risk of AF (pooled relative risk [RR] 0.56, 95% confidence interval [CI] 0.47 to 0.68). The duration of follow-up for outcome assessment was unclear.
  • Analysis taking into account various other patient factors did not find that age, gender, body mass index, high blood pressure or diabetes had a significant influence on the risk of AF recurrence.
  • Based on the results from these studies, the researchers estimate that CPAP use in people with obstructive sleep apnoea who have been treated for AF may prevent 17% of them from getting AF recurrence.

What does current guidance say on this issue?

NICE guidance from 2008 recommends using CPAP treatment for people with moderate to severe obstructive sleep apnoea. There is no guidance on identifying AF in people with obstructive sleep apnoea, or recommendations for treatment approach in these people.

What are the implications?

This review found that use of CPAP in people with obstructive sleep apnoea who have been treated by catheter ablation for recurrent atrial fibrillation was linked with reduced risk of recurrence. However, the observational design of most of the included studies limits the applicability of the findings.

The reasons underlying the association between obstructive sleep apnoea and atrial fibrillation are not clearly understood. The reviewers did not find that the variables they examined had an influence on the outcome, but noted that the patient groups were variable and information on severity was not available. There remains the possibility that patient characteristics have influenced treatment decisions.

Other practical implications relate to acceptability and cost. There was no assessment of how acceptable the participants found CPAP. Poor acceptability of the treatment has been highlighted as a major problem in previous reliable Cochrane reviews. There was also no economic evaluation. The authors noted that health services are not configured to look for and treat both conditions at the same time. The cost implications from specialist diagnosis of obstructive sleep apnoea and subsequent CPAP treatment – particularly if considering screening people with AF for the condition – are likely to be high.

Overall, though the findings seem promising, further research into the link is needed before considering changing guideline recommendations. Service reorganisation would be required before translating the findings to practice.

Citation

Qureshi WT, Nasir UB, Alqalyoobi S, et al. Meta-analysis of continuous positive airway pressure as a therapy of atrial fibrillation in obstructive sleep apnea. Am J Cardiol. 2015;116(11):1767-73.

Bibliography

BHF. Atrial fibrillation [internet]. London: British Heart Foundation; undated.

BLF. Obstructive sleep apnoea (OSA) [internet]. London: British Lung Foundation; 2014.

Giles TL, Lasserson TJ, Smith B, et al. Continuous positive airways pressure for obstructive sleep apnoea in adults. Cochrane Database Syst Rev. 2006;(3):CD001106.

Ng CY, Liu T, Shehata M, Stevens S, Chugh SS, Wang X. Meta-analysis of obstructive sleep apnea as predictor of atrial fibrillation recurrence after catheter ablation. Am J Cardiol. 2011;108:47-51.

NHS Choices. Atrial fibrillation [internet]. NHS Choices; 2015.

NHS Choices. Obstructive sleep apnoea [internet]. NHS Choices; 2014.

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

NICE. Continuous positive airway pressure for the treatment of obstructive sleep apnoea/hypopnoea syndrome. TA139. London: National Institute for Health and Care Excellence; 2008.

Shukla A, Aizer A, Holmes D, et al. Effect of obstructive sleep apnea treatment on atrial fibrillation recurrence. A meta-analysis. JACC Electrophysiol. 2015;1:41-51.

Smith I, Lasserson TJ. Pressure modification for improving usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea. Cochrane Database Syst Rev. 2009;(4):CD003531.

Wozniak DR, Lasserson TJ, Smith I. Educational, supportive and behavioural interventions to improve usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea. Cochrane Database Syst Rev. 2014;(1):CD007736.

Why was this study needed?

Obstructive sleep apnoea is thought to affect up to 4% of middle-aged men and 2% of middle-aged women in the UK. The condition has been found in association with AF, the most common type of heart rhythm abnormality, which affects around 2% of people in the UK. Previous research has suggested that people with obstructive sleep apnoea are six times as likely to have AF as the general population, and those with AF are more than twice as likely to have obstructive sleep apnoea. The reasons for the link are incompletely understood.

It is thought that obstructive sleep apnoea is under-diagnosed in people with recurrent AF and that by improved detection the treatment of recurrent AF could be improved.

The aim of this review was to determine whether using CPAP to treat people with obstructive sleep apnoea and recurrent AF after a catheter ablation (see Definitions), could reduce the chances of AF recurring. AF recurs in about a quarter to two thirds of cases within 5 years of an ablation or cardioversion (see Definitions).

What did this study do?

This systematic review included eight studies including 1,247 adults with obstructive sleep apnoea who had been treated for AF by catheter ablation. Of these people 698 had used CPAP and 549 were non-users. The researchers compared risk of AF recurrence between the two groups of people.

The review met reporting standards and assessed quality of included studies using Cochrane guidelines. However, most of the studies included less than 200 participants, and only one of the eight studies was a randomised controlled trial (of low quality), the rest were cohort studies. Observational studies cannot provide such robust evidence as randomised controlled trials because patient characteristics may have influenced the decision to use CPAP or not, and may also influence risk of AF recurrence.

The review did not address patient preferences or experiences of using CPAP.

What did it find?

  • Across the eight studies, AF recurred in 18% of those who used CPAP and 37% of those who did not. This meant that CPAP was associated with 44% reduced risk of AF (pooled relative risk [RR] 0.56, 95% confidence interval [CI] 0.47 to 0.68). The duration of follow-up for outcome assessment was unclear.
  • Analysis taking into account various other patient factors did not find that age, gender, body mass index, high blood pressure or diabetes had a significant influence on the risk of AF recurrence.
  • Based on the results from these studies, the researchers estimate that CPAP use in people with obstructive sleep apnoea who have been treated for AF may prevent 17% of them from getting AF recurrence.

What does current guidance say on this issue?

NICE guidance from 2008 recommends using CPAP treatment for people with moderate to severe obstructive sleep apnoea. There is no guidance on identifying AF in people with obstructive sleep apnoea, or recommendations for treatment approach in these people.

What are the implications?

This review found that use of CPAP in people with obstructive sleep apnoea who have been treated by catheter ablation for recurrent atrial fibrillation was linked with reduced risk of recurrence. However, the observational design of most of the included studies limits the applicability of the findings.

The reasons underlying the association between obstructive sleep apnoea and atrial fibrillation are not clearly understood. The reviewers did not find that the variables they examined had an influence on the outcome, but noted that the patient groups were variable and information on severity was not available. There remains the possibility that patient characteristics have influenced treatment decisions.

Other practical implications relate to acceptability and cost. There was no assessment of how acceptable the participants found CPAP. Poor acceptability of the treatment has been highlighted as a major problem in previous reliable Cochrane reviews. There was also no economic evaluation. The authors noted that health services are not configured to look for and treat both conditions at the same time. The cost implications from specialist diagnosis of obstructive sleep apnoea and subsequent CPAP treatment – particularly if considering screening people with AF for the condition – are likely to be high.

Overall, though the findings seem promising, further research into the link is needed before considering changing guideline recommendations. Service reorganisation would be required before translating the findings to practice.

Citation

Qureshi WT, Nasir UB, Alqalyoobi S, et al. Meta-analysis of continuous positive airway pressure as a therapy of atrial fibrillation in obstructive sleep apnea. Am J Cardiol. 2015;116(11):1767-73.

Bibliography

BHF. Atrial fibrillation [internet]. London: British Heart Foundation; undated.

BLF. Obstructive sleep apnoea (OSA) [internet]. London: British Lung Foundation; 2014.

Giles TL, Lasserson TJ, Smith B, et al. Continuous positive airways pressure for obstructive sleep apnoea in adults. Cochrane Database Syst Rev. 2006;(3):CD001106.

Ng CY, Liu T, Shehata M, Stevens S, Chugh SS, Wang X. Meta-analysis of obstructive sleep apnea as predictor of atrial fibrillation recurrence after catheter ablation. Am J Cardiol. 2011;108:47-51.

NHS Choices. Atrial fibrillation [internet]. NHS Choices; 2015.

NHS Choices. Obstructive sleep apnoea [internet]. NHS Choices; 2014.

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

NICE. Continuous positive airway pressure for the treatment of obstructive sleep apnoea/hypopnoea syndrome. TA139. London: National Institute for Health and Care Excellence; 2008.

Shukla A, Aizer A, Holmes D, et al. Effect of obstructive sleep apnea treatment on atrial fibrillation recurrence. A meta-analysis. JACC Electrophysiol. 2015;1:41-51.

Smith I, Lasserson TJ. Pressure modification for improving usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea. Cochrane Database Syst Rev. 2009;(4):CD003531.

Wozniak DR, Lasserson TJ, Smith I. Educational, supportive and behavioural interventions to improve usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea. Cochrane Database Syst Rev. 2014;(1):CD007736.

Meta-Analysis of Continuous Positive Airway Pressure as a Therapy of Atrial Fibrillation in Obstructive Sleep Apnea

Published on 21 October 2015

Qureshi, W. T.,Nasir, U. B.,Alqalyoobi, S.,O'Neal, W. T.,Mawri, S.,Sabbagh, S.,Soliman, E. Z.,Al-Mallah, M. H.

Am J Cardiol , 2015

Atrial fibrillation (AF) is a significant health care problem for patients with obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) as a therapy for OSA is underused, and it is unknown if CPAP might reduce rates of AF. We systematically reviewed the published reports on CPAP use and risk of AF. MEDLINE, EMBASE, CINAHL, Web of Science, meeting abstracts, and Cochrane databases were searched from inception to June 2015. Studies needed to report the rates of AF in participants who were and were not on CPAP. Data were extracted by 2 authors. A total of 8 studies on OSA were identified (1 randomized controlled trial) with 698 CPAP users and 549 non-CPAP users. In a random effects model, patients treated with CPAP had a 42% decreased risk of AF (pooled risk ratio, 0.58; 95% confidence interval, 0.47 to 0.70; p <0.001). There was low heterogeneity in the results (I2 = 30%). In metaregression analysis, benefits of CPAP were stronger for younger, obese, and male patients (p <0.05). An inverse relationship between CPAP therapy and AF recurrence was observed. Results suggest that more patients with AF also should be tested for OSA.

Obstructive sleep apnoea is a condition where the walls of the throat relax and close off the airways during sleep. This interruption to normal breathing can happen many times a night, leading to low oxygen levels in the blood and daytime sleepiness. The condition is more common in older people, males and overweight people. The symptoms typically include snoring and daytime sleepiness.

This study defined moderate to severe obstructive sleep apnoea as more than four occasions of obstructed breathing per hour, measured with monitoring equipment during a sleep study.

Continuous positive airway pressure (CPAP) is a treatment where a close-fitting mask over the nose delivers air under slightly raised pressure to help keep the airways open.

Atrial fibrillation is an irregular heart rhythm which can lead to reduced efficiency of the heart and to strokes. The irregular rhythm may last a short time but may recur or may become established, with no return to normal regular rhythm.

Catheter ablation is a procedure aimed at reducing recurrences of atrial fibrillation (AF) that very carefully destroys a small area of heart muscle, interrupting the abnormal electrical circuits that cause atrial fibrillation. The catheters are thin, soft wires which are guided through veins into the heart, where they record electrical activity. An energy source, such as high-frequency electrical current, that generates heat is used to destroy the tissue. The procedure usually takes two to three hours and may be carried out under a general anaesthetic.

Cardioversion is a procedure where abnormally fast heart rhythm is returned to normal using drugs or a therapeutic, controlled electric shock.

Expert commentary

The findings of this rigorous meta-analysis are in line with the biologically plausible association that has been observed between these two common conditions. Results are persuasive and consistent between studies, but there remains a need for level 1 evidence (randomised clinical trials) focussed on screening as well as intervention. Meanwhile cardiologists should be encouraged to be vigilant for features of obstructive sleep apnoea and sleep physicians should be allowed flexibility in their continuous positive airway pressure threshold when dealing with this specific group of patients.

Dr Tim Quinnell, Papworth Respiratory Support and Sleep Centre, Papworth Hospital NHS Foundation Trust