Sleep apnea common in AF, often undiagnosed
Despite its prevalence in patients with atrial fibrillation, sleep apnea is often undiagnosed in this patient population, researchers found.
The study, published in JACC: Clinical Electrophysiology, also showed that standard questionnaires to identify patients with sleep apnea have limited predictive value in patients with AF. Once patients with AF are identified as having sleep apnea, they often have improved adherence to long-term continuous positive airway pressure ventilators.
“The reason why sleep apnea symptoms are less predictive in patients with AF remains speculative, but it is possible that symptoms attributed to sleep apnea are also frequent in AF patients due to the impact of AF itself on symptoms and quality of life,” Ayelet Shapira-Daniels, MD, National Research Service Award research fellow of cardiac electrophysiology at Beth Israel Deaconess Medical Center when conducting this study and now an internal medicine intern at Boston Medical Center, and colleagues wrote. “Alternatively, there is an increasing body of evidence that patients with AF and sleep apnea do not experience excessive daytime sleepiness in a similar way as the general population.”
Patients scheduled for ablation
In this prospective study, researchers analyzed data from 188 patients (mean age, 62 years; 65% men) with symptomatic persistent or paroxysmal AF who were scheduled for an ablation procedure and did not report a history of sleep apnea. All patients underwent a home sleep apnea test and completed the Stop-Bang screening questionnaire, which takes into consideration the following signs and/or symptoms: tiredness, snoring, choking/apnea during sleep, BMI greater than 35 kg/m2, hypertension, neck circumference greater than 40 cm, older than 50 years and male sex.
The primary endpoint was the prevalence of a positive home sleep apnea test. The secondary endpoint for this study was the predictive value of the sleep apnea questionnaire and common symptoms of sleep apnea to detect the condition in patients with AF. Patients with a positive sleep study were also assessed for initiation of and adherence to sleep apnea therapies.
Positive home sleep apnea tests were observed in 82.4% of patients. Of those who tested positive, 82% had a predominant obstructive component and 18% had mild to moderate severity of a central sleep apnea component of 15.2%. In addition, the severity of sleep apnea was severe in 23.2%, moderate in 32.9% and mild in 43.8%.
The Stop-Bang questionnaire had a sensitivity of 81.2% and a specificity of 42.4%. The multivariate analysis determined that this questionnaire was not predictive for sleep apnea in patients with AF (OR = 0.54; 95% CI, 0.17-1.76).
Among 85 patients with moderate or severe sleep apnea, 85.8% started therapy with continuous positive airway pressure ventilators. After a mean follow-up of 21 months, 93.1% of those patients were compliant with this therapy.
Optimal screening test needed
“Although screening all AF patients is likely to unmask a large proportion of undiagnosed sleep apnea, more research is required to identify the optimal method to test for sleep apnea and to evaluate the impact of its therapy on AF burden and overall well-being,” Shapira-Daniels and colleagues wrote.