Catheter Ablation
Screening for Sleep Apnea in Atrial Fibrillation Prior to Catheter Ablation
2021 年 85 巻 3 号 p. 261-263
詳細
2021 年 85 巻 3 号 p. 261-263
Obstructive sleep apnea (OSA) is highly prevalent in atrial fibrillation (AF) patients,1 and such a high prevalence may reflect a cause-and-effect relationship. OSA is reportedly associated with incident AF,2 and the mechanisms linking OSA and AF include activation of the sympathetic nervous system with intermittent hypoxia and arousal and structural remodeling of the left atrium through the negative intrathoracic pressure during futile respiratory efforts against the occluded upper airway. Regarding cardiac electrical remodeling, prolonged atrial conduction time is expressed as a wide P-wave and long sinus node recovery time in OSA patients,3 all of which contribute to AF onset. In addition, OSA is a risk factor for recurrent AF following rhythm control treatment. A meta-analysis reported that OSA was associated with a 25% greater risk of AF recurrence after pulmonary vein isolation therapy.4 The link between OSA and AF recurrence is supported by previous data that OSA treatment with continuous positive airway pressure (CPAP) is associated with reductions in AF recurrence rates following catheter ablation (CA).5 A recent meta-analysis6 of 9 prospective cohort studies with 2,134 participants reported that CPAP was associated with a 37% relative risk reduction in AF recurrence in OSA patients under rhythm control strategies. Based on these data, AF patients should be screened for OSA, given its clinical effect. However, it remains unclear how and when to test for OSA in the standard care of AF patients. The latest guideline by the European Society of Cardiology (ESC) for the management of AF states that, with a Class IIa recommendation, “opportunistic screening for AF should be considered in patients with OSA.”7 The ESC guideline also states that optimal OSA management may be considered with a Class IIb recommendation and that “It seems reasonable to test for OSA before the initiation of rhythm control therapy in symptomatic AF patients, with the aim to reduce symptomatic AF recurrences.”7 The Japanese Cardiology Society guideline states that medical OSA consultation for AF patients is recommended with Class I, and screening tests should be considered for AF patients with suspected OSA.8 The Canadian Cardiology Society guideline states that “Sleep study or overnight oximetry should be considered in most patients because typical symptoms are less prevalent and screening questionnaires are less accurate in AF patients.”9 Although the link between OSA and AF is well recognized, a limited number of AF patients have been tested for OSA and started on CPAP therapy, largely because of limited access to polysomnography (PSG), the standard diagnostic test for sleep-disordered breathing. The home sleep apnea test (HSAT), which is much easier to administer than PSG, can help overcome this issue. HSAT can provide the frequency of apneas or hypopneas (i.e., the apnea-hypopnea index [AHI]), which is highly correlated with the AHI assessed using PSG. However, according to the current Japanese health insurance system, CPAP indications include AHI ≥20 assessed using PSG or AHI ≥40 assessed using the HSAT. Therefore, AF patients and patients with AHI <40 using the HSAT have to undergo additional PSG to determine CPAP indication. PSG is time-consuming and costly, so only a few institutions offer it. Because many AF and OSA patients are asymptomatic for OSA,10 they are unwilling to be tested and pay for it, even if their attending doctors try to convince them to take the test.
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In this issue of the Journal, Tanaka et al11 provide valuable insights regarding sleep apnea detection using HSAT in AF patients. Before CA, the authors examined the prevalence of sleep apnea in AF patients using a peripheral arterial tonometry (PAT)-based HSAT device (Watch-PAT; Itamar Medical Ltd., Caesarea, Israel). The usefulness of this device in assessing sleep apnea in cardiovascular disease patients was established in a Japanese multicenter study comparing AHI determined using this device with that determined using PSG.12 That study reported that sleep apnea defined as an AHI ≥5 was observed in 88.6% of 774 AF patients undergoing CA. Moderate-to-severe sleep apnea defined as an AHI ≥15 was observed in 53.2% of patients, but over half of them did not have sleep apnea symptoms. Despite the retrospective observational design in a single institution, sleep apnea identified using the HSAT was highly prevalent in AF patients undergoing CA, and over half of the patients with moderate-to-severe sleep apnea were asymptomatic, suggesting the need for OSA screening in AF patients regardless of the presence of OSA-related symptoms. Several limitations, some of which are acknowledged by the authors themselves, should be considered when interpreting the current study results. First, the HSAT device could not determine the type of sleep apnea. Some AF patients may have central sleep apnea. Second, the PAT-based device indirectly detects apnea and hypopnea by selectively measuring peripheral arterial volume changes using a finger-mounted plethysmograph. In AF patients, irregular heartbeats may influence beat-to-beat peripheral arterial volume changes. Thus, it is unclear whether the algorithm of the PAT-based device is accurately applicable for HSAT of patients with persistent or frequent paroxysmal AF at night.
Nevertheless, the advantages of the HSAT over PSG include its availability and cost-effectiveness. Kawakami et al recently reported the cost-effectiveness of facilitating OSA screening using the HSAT before CA in AF patients.13 In their hypothetical cohort, cost-effectiveness was assessed using costs, quality-adjusted life years, and an incremental cost-effectiveness ratio from the Japanese health insurance system and compared among patients without screening, patients with HSAT-guided screening, and patients with PSG-guided screening. HSAT-guided screening was the most cost-effective at a willingness-to-pay threshold of 5,000,000 Japanese yen. Revision of CPAP indications for OSA based on HSAT results could reduce AF recurrence in AF and OSA patients and its related costs and alleviate healthcare cost burden (Figure).
Increasing need for home sleep apnea test (HSAT) screening in atrial fibrillation (AF) patients. Given the higher prevalence and clinical effect of obstructive sleep apnea (OSA) in AF patients and PSG-related access issues, systematic screening with the HSAT for sleep apnea in AF patients could be beneficial for stratifying patients at high risk of AF recurrence. CA, catheter ablation; CPAP, continuous positive airway pressure; PSG, polysomnography.
None.
T.K. received research funds from ResMed. A.S. and R.N. are affiliated with a department endowed by Philips, ResMed, and Fukuda Denshi.
