Should we incorporate obstructive sleep apnea in CHA2DS2-VASc score?

Atrial fibrillation (AF) is considered a significant challenge in cardiovascular medicine related to significant morbidity and mortality. Obstructive sleep apnea (OSA) is associated with stroke and constitutes an important risk factor for AF. However, it is still ambiguous whether OSA is independently related to stroke or systemic embolism in AF patients, and whether or not OSA should be included in CHA2DS2-VASc score. In a recent study, the presence of OSA in patients with AF was associated with higher rates of adverse events, namely stroke and systemic embolism. Patients with OSA have higher CHA2DS2-VASc scores and mean CHA2DS2-VASc scores that increase with OSA severity. The addition of OSA to CHA2DS2-VASc resulted in improved discrimination, but this improvement was modest and clinically non-significant. However, cardiovascular risk factors that accompany OSA and not OSA per se might be responsible for the increased thromboembolic risk in these patients. It is noteworthy that patients with OSA with CHA2DS2-VASc <2 had a higher incidence of stroke compared to those without. Unfortunately, the event rates for stroke in these patients were too low to reach statistically validated conclusions. Therefore, it seems reasonable to suggest that in borderline stroke risk patients (CHA2DS2-VASc <2), the presence of OSA should be taken into account in the treatment decision. More studies are needed to elucidate whether or not OSA should be incorporated in CHA2DS2-VASc score.