82% of AFib patients have undiagnosed sleep apnea, highlighting the importance of screening

A significant number of atrial fibrillation (AFib) patients who are referred for ablation have undiagnosed sleep apnea, according to a new study published in JACC: Clinical Electrophysiology.

“The growing number of patients with AFib have stimulated efforts in prevention strategies, targeting risk factors such as obesity, hypertension, diabetes and sleep apnea,” wrote lead author Ayelet Shapira-Daniels, MD, of the Harvard-Thorndike Electrophysiology Institute in Boston, and colleagues. “In regard to the latter, observational studies suggest that obstructive sleep apnea is a modifiable risk factor for recurrent AFib as treatment with continuous positive airway pressure (CPAP) therapy reduced the incidence of AFib recurrence after cardioversion or ablation. Furthermore, recent data suggest that patients with OSA have higher incidence of non-pulmonary vein triggers, and ablation of these triggers reduces the risk of AFib recurrence in comparison to pulmonary vein isolation alone.”

These findings, the authors wrote, emphasize the importance of detecting sleep apnea in AFib patients; it can be a huge advantage both before and after treatment.

Shapira-Daniels et al. examined data from two hospitals where catheter ablation is routinely performed to treat AFib—one in Boston and another in Austin, Texas. The team focused on nearly 200 consecutive patients treated from January 2016 to December 2017 at the hospital in Boston and patients treated from January to June 2015 at the hospital in Austin.

Overall, 82.4% of patients referred for ablation were diagnosed with sleep apnea through a test that can be taken at home. Of those patients, 82% had a predominant obstructive component. Sleep apnea severity was mild for 43.8% of patients, moderate for 32.9% and severe for 23.2%.

Each study participant took a STOP-BANG questionnaire during their pre-procedure clinical visit. The researchers found that this questionnaire had a sensitivity of 81.2% and specificity of 42.4%, concluding that it “was not predictive for sleep apnea.”

Another key finding from the team’s work is that 93% of patients who were prescribed CPAP therapy remained compliant after a mean follow-up of approximately 21 months.

“Following diagnosis, adherence to sleep apnea therapy was high and further emphasizes the need to discover undiagnosed sleep apnea in these patients,” the authors concluded. “Although screening all AFib 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 AFib burden and overall well-being.”

The full study is available here.