Impact of obstructive sleep apnoea on long-term atrial fibrillation-free survival after catheter ablation
Authors: De Almeida Fernandes D , Paiva P , Guimaraes J M , Antonio N , Goncalves L 
Published: October 2022

Abstract

Introduction
Early rhythm-control therapy of atrial fibrillation (AF) (including catheter ablation) has been established as significantly lowering risk of adverse cardiovascular outcomes and improving overall survival and quality of life. Obstructive sleep apnoea (OSA) is a common but often overlooked comorbidity in patients with AF that may lead to difficulties in maintaining sinus rhythm. Data on the impacts of its treatment on recurrence remain conflicting.

Objective
To determine the prevalence of OSA in a population of AF patients submitted to catheter ablation and its impact on recurrence after a successful procedure.

Methods
Retrospective study of patients with AF consecutively submitted to catheter ablation in a tertiary centre between January 2017 and December 2020. The main outcome was AF recurrence after ablation. Sociodemographic variables and clinical data were retrieved for each patient, including type of AF, comorbidities, screening and diagnosis of OSA, treatment of OSA prior to ablation, time from ablation to recurrence of AF, method of ablation (radiofrequency or cryo). Statistical comparison between patients with and without OSA was made, including survival curves and Cox regression to determine time to recurrence and adjust for confounding variables.

Results
A total of 189 patients were included with a mean age of 63.49±11.09 years. Mean follow-up time after ablation was 2.76±1.56 years. Patients who recurred after ablation had undergone more electrical cardioversions prior to the procedure (1.640±1.583 vs 0.800±0.966, p 0.002), had more persistent AF (p 0.036) and had more OSA (32.7% vs 15.7%, p=0.011). There were no differences regarding age, gender, body-mass index, history of hypertension, diabetes, chronic kidney disease or heart failure, method of ablation and diagnosis of OSA prior to ablation.
Forty-nine patients (18.7%) had OSA, with only 16 (32.7%) having been diagnosed before ablation. OSA was screened in only 60 cases (31.7%), mostly due to symptoms (76.1%) and not per protocol. Patients with OSA had earlier recurrence of AF after ablation (p Log-rank 0.012) with a hazard two times greater of recurrence, even after adjusting for confounding (p 0.026; hazard-ratio 2.025; confidence interval 95% 1.086–3.775). One year recurrence rate was 31% in patients with OSA (vs 15%). Regarding patients under treatment for OSA prior to ablation, there was no difference in survival (p Log-rank 0.859).

Conclusion
In real-world practice, OSA is still a largely underinvestigated condition that significantly impairs AF control and contributes to worse cardiovascular outcomes. Recurrence was 2 times higher in patients with OSA. No impact of treatment in time to recurrence was found. Efforts must be made to increase screening of this condition in order to improve outcomes. Further studies are needed to clarify the benefits of OSA treatment in AF recurrence.

Funding Acknowledgement
Type of funding sources: None.