It is well known that obstructive sleep apnea (OSA) is associated with AF. There is data supporting increased recurrence of AF after cardioversion in patient with OSA. If OSA also impairs the success of AF ablation is not well documented. Matiello et al. have performed a prospective study to evaluate the same and found that severe OSA is associated with low efficacy of AF ablation [1].

Matiello et al. in their single center study screened 174 patients undergoing AF ablation prospectively to identify their risk of OSA using a Berlin Questionnaire (BQ). Patients with high risk of OSA (51 patients; 29%) underwent a formal sleep study and those with OSA (42 patients) were divided into non-severe (17 patients) and severe (25 patients) OSA groups. Patients who had low BQ score and did not undergo sleep study and those with a negative sleep study were included in the low risk for OSA group (control group; 132 patients).  All patients underwent pulmonary vein isolation with a left atrial roof line. Most patients also underwent a posterior left atrial line. Patients were followed-up at 1, 3 and 7 month intervals and as needed thereafter with routine 24-48 hour holter monitoring. Mean follow-up was 17 months and success was defined survival free of AF or left atrial flutter off antiarrhythmics.  

At baseline OSA patients had higher body mass index and left ventricular dimensions and a higher incidence of structural heart disease and hypertension when compared to the control group. There were no differences in the procedure variables between the groups. After 1 year follow-up the arrhythmia free survival after a single procedure was 49%, 39% and 14% in the control, non-severe OSA and severe OSA groups respectively (p< 0.001 between control and severe OSA groups). Second procedure was performed in 58 (33%) patients. When the second procedure was also considered, the arrhythmia free survivals at the end of 1 year were 69%, 44% and 14% respectively (p< 0.001 between control and severe OSA groups;  p=0.019 between control and non-severe OSA groups). Left atrial diameter and severe OSA were the only independent predictors of arrhythmia recurrence.

This study adds to the previous evidence that OSA is associated with higher failure rate after AF ablation [2,3]. Various physiological mechanisms have been identified and proposed which explain the increased prevalence of AF in OSA patients. In OSA patients the AF substrate is probably more extensive with more AF triggers within or outside the left atrium. In summary, current evidence suggests that severe OSA has to be considered as a poor prognostic sign for recurrence after AF ablation. We need more prospective studies to evaluate 1) if continuous positive airway pressure (CPAP) treatment would mitigate the negative effect of OSA on AF recurrence and 2) if more extensive ablation beyond PVI is indicated in all patients in this “sicker substrate” patient group.

References:

1. Matiello M, Nadal M, Tamborero D, Berruezo A, Montserrat J, Embid C, Rios J, Villacastín J, Brugada J, Mont L. Low efficacy of atrial fibrillation ablation in severe obstructive sleep apnoea patients. Europace. 2010 Aug;12(8):1084-9.

2. Chilukuri K, Dalal D, Marine JE, Scherr D, Henrikson CA, Cheng A, Nazarian S, Spragg D, Berger R, Calkins H. Predictive value of obstructive sleep apnoea assessed by the Berlin Questionnaire for outcomes after the catheter ablation of atrial fibrillation. Europace. 2009 Jul;11(7):896-901.

3. Tang RB, Dong JZ, Liu XP, Kang JP, Ding SF, Wang L, Long DY, Yu RH, Liu XH, Liu S, Ma CS. Obstructive sleep apnoea risk profile and the risk of recurrence of atrial fibrillation after catheter ablation. Europace. 2009 Jan;11(1):100-5.