Background: CPAP therapy has a variable effect on central sleep apnea with Cheyne-Stokes respiration (CSA-CSR). Adaptive servoventilation (ASV) is more effective in normalising breathing in patients with heart failure. We hypothesised that, by normalising AHI, ASV reduces elevated BNP levels in patients with mild systolic and diastolic heart failure.
Methods: From April 2004 to October 2006, patients with CSA-CSR with and without concomitant obstructive sleep apnea (OSA), clinical evidence of heart failure, regardless EF, and elevated BNP levels (> 100 pg/mL) were selected for treatment with ASV, unless CPAP therapy had reduced AHI to < 15 per hour of sleep. Follow-up polysomnographies and BNP analyses were performed after 6 weeks.
Results: 15-male patients (AHI 48.3 +/- 14.6/h) fulfilled all inclusion criteria; 7 patients had CSA-CSR + OSA, 8 had CSA-CSR. After 6 weeks of ASV, BNP decreased from 415 +/- 196 pg/mL to 264 +/- 146 pg/mL (p = 0.0009). There was only a significant BNP reduction in the CSA-CSR+OSA subgroup (p = 0.0002).
Conclusion: ASV can normalise AHI in patients with mild systolic and diastolic heart failure and CSA-CSR +/- OSA, thus leading to a significant reduction of BNP levels. These findings suggest that effective suppression of sleep apnoea in such heart failure patients improves cardiac function.
Georg Thieme Verlag KG Stuttgart. New York.