Impact of sleeping position on central sleep apnea/Cheyne-Stokes respiration in patients with heart failure

Background: The present study determines the influence of sleeping position on central sleep apnea (CSA) in patients with heart failure (HF). Methods: The apnea/hypopnea index (AHI) during different body positions while asleep was examined by cardiorespiratory polygraphy in 71 patients with HF (ejection fraction <45%). Results: Twenty-five of the patients having predominantly CSA (central apnea index ≥10/h) with a lower obstructive apnea index (<5/h) were assigned to groups with positional (lateral to supine ratio of AHI <50%, n = 12) or non-positional (ratio ≥50%, n = 13) CSA. In the non-positional group the BNP level was higher, the ejection fraction was lower and the trans-tricuspid pressure gradient was higher than in the positional group. Multiple regression analysis revealed more advanced age (p = 0.006), log₁₀ BNP (p = 0.017) and lung-to-finger circulation time (p = 0.020) as independent factors of the degree of positional CSA. Intensive treatment for HF changed CSA from non-positional to positional in all eight patients tested. Single night of positional therapy reduced CSA (p < 0.05) and BNP level (p = 0.07) in seven positional patients. Conclusion: As cardiac dysfunction progresses, severity of CSA also increases and positional CSA becomes position-independent. Positional therapy could decrease CSA, thereby having a valuable effect on HF.