CPAP use in OSA patients leads to reverse atrial remodeling, may reduce AF burden, SLEEP-AF study.

The association of atrial fibrillation (AF) with obstructive sleep apnea (OSA) is highly prevalent, yet remains pathophysiologically enigmatic. Although continuous positive airway pressure (CPAP) therapy is one of the most effective strategies to manage symptoms of OSA, its impact on atrial arrhythmogenicity has not been studied in randomized trials.

However, the results of a randomized trial- the SLEEP AF study, published recently in JACC CE, has shed light on this topic and shown that CPAP therapy results in reversal of atrial remodeling in AF. This provides mechanistic evidence advocating for management of OSA in AF.

The study team recruited 24 OSA patients to undergo baseline right atrial electrophysiologic mapping, followed by randomization to either CPAP therapy or no OSA therapy. After >6 months, these patients underwent a repeat invasive right atrial mapping study.

Outcome variables were atrial voltage (mV), conduction velocity (m/s), atrial surface area <0.5 mV (%), proportion of complex points (%), and atrial effective refractory periods (ms). Change between groups over time was compared.

It was found that an effective CPAP therapy (high CPAP adherence was achieved) resulted in faster atrial conduction velocity and higher atrial bipolar voltage than no CPAP therapy, independent of changes in systemic blood pressure or weight. CPAP therapy also resulted in a trend toward lower proportion of atrial surface area <0.5 mV.

"These are crucial findings, because prolonged atrial conduction time is among the most powerful predictors of AF development in the general population. If we accept that AF susceptibility is defined by a sum of AF substrate and AF triggers (AF susceptibility = AF substrate + AF triggers), and these randomized data show that CPAP improves AF substrate while not changing the AF overall susceptibility (aka AF outcomes), then a logical conclusion could lead us to suspect that AF triggers caused by OSA may be playing a more prominent role in the initiation and sustainment of AF than previously thought.", note Konecny et al in an accompanying editorial.

The present study demonstrates that CPAP therapy alone can at least partially reverse atrial remodeling in patients with OSA. In this study, body mass index and blood pressure remained unaffected, indicating that reverse remodeling was mediated by CPAP therapy alone.

Whether or not OSA treatment alone and the associated reverse remodeling will lead to reduction in AF burden and improved AF treatment outcomes awaits data from ongoing randomized trials.

Source: JACC CE

1. J Am Coll Cardiol EP. 2022 Jul, 8 (7) 869–877

2. J Am Coll Cardiol EP. 2022 Jul, 8 (7) 878–88