To Treat or Not to Treat

The focus of this chapter is central sleep apnea with Cheyne-Stokes breathing (CSA-CSB), a hypocapnic central sleep apnea commonly observed in patients with congestive heart failure (HF). The pathophysiologic aspects of CSA-CSB are discussed, including ventilatory responsiveness and concepts of loop gain, apneic threshold, and narrowing of the carbon dioxide delta gap serving as a predisposing factor. Complexities of the clinical approach are reviewed in terms of clinically contextualizing the findings from a large randomized controlled trial demonstrating increased cardiovascular-specific mortality in patients randomized to adaptive servo ventilation versus controls in those with central-predominant sleep apnea and reduced ejection fraction HF. Potential mechanistic explanations for these findings are reviewed and placed into context with available post hoc analyses from this trial. Treatment options are discussed, including the role of other positive airway pressure (PAP) modalities, supplemental oxygen, relevant medications, and innovative non-PAP therapies such as transvenous phrenic nerve stimulation.