Occult obstructive sleep apnea and clinical outcomes of radiofrequency catheter ablation in patients with atrial fibrillation.

BACKGROUND: Recurrent atrial fibrillation (AF) after successful cardioversion can be predicted by obstructive sleep apnea (OSA) diagnosed by polysomnography. However, it is not known whether the validated STOP-BANG questionnaire can predict AF recurrence after radiofrequency ablation (RFA). Our objective is to determine the prevalence of unrecognized OSA in patients with AF and its relation to freedom from AF after RFA.

METHODS: Validated surveys were administered to 247 consecutive AF patients following radiofrequency ablation from January to October 2011. OSA status was assessed at baseline RFA. Clinical follow up occurred at 3-6 month intervals.

RESULTS: OSA had been previously diagnosed in 94/247 (38%). Among 153 patients without prior diagnosis of OSA, 121 (79%) had high risk STOP-BANG scores for OSA. Probability of maintaining sinus rhythm after RFA was similar among patients with known OSA (66/94, 70%) and high risk OSA scores (95/124, 77%) and higher than among patients with low risk OSA scores (29/32, 91%, P=0.03). Among patients without prior OSA, a high risk STOP-BANG score did predict recurrent AF (OR = 3.7, 95 % CI 1.4-11.4, P = 0.0005). Multivariate analysis showed a higher risk of atrial arrhythmia recurrence for non-paroxysmal AF patients (OR = 3.1, ± 95 % CI 1.4-7.1, P = 0.005).

CONCLUSIONS: The majority of AF patients undergoing RFA have high risk OSA scores, suggesting that OSA is vastly underdiagnosed in this population. STOP-BANG independently predicted recurrent AF in patients without a prior diagnosis of OSA.