Efficacy of adaptive servoventilation in patients with congestive heart failure and Cheyne-Stokes respiration

Abstract

Congestive heart failure (CHF) is associated with Cheyne-Stokes respiration (CSR), which may hasten CHF. Adaptive servoventilation (ASV) is a novel method of ventilatory support designed for removal of CSF in CHF patients. This study compares the efficacy of ASV in patients with CHF and CSR with the efficacy of oxygen therapy. Fourteen patients with CHF and CSR were recruited. During sleep, nasal oxygen therapy and ASV treatment were each performed for two weeks. Comparison before and after each treatment was made for the following items: a) parameters of sleep respiration, sleep structure and quality; b) left ventricle ejection fraction (LVEF) and 6-minute walk distance. Compared with the baseline levels of apnoea hypopnoea index of 34.5 +/- 6.1 before treatment, the apnoea hypopnoea index significantly decreased following oxygen therapy to 27.8 +/- 8.2, P < 0.05 and further reduced following ASV treatment to 6.5 +/- 0.8, P < 0.01. The minimal pulse oxygen saturation markedly increased following oxygen therapy from a baseline of (84.3 +/- 2.6)% to (88.6 +/- 3.7)%, P < 0.05 and further increased following ASV treatment (92.1 +/- 4.9)%, P < 0.01. Stages I + II sleep as percentage of total sleep time decreased from (81.9 +/- 7.1)% to (78.4 +/- 6.7)% following oxygen therapy and further to (72.4 +/- 5.0)% following ASV treatment. Stages III + IV sleep as percentage of total sleep time decreased from (8.4 +/- 5.5)% to (6.0 +/- 3.0)% following oxygen therapy and but increased to (11.9 +/- 5.4)% following ASV treatment. The arousal index of 30.4 +/- 8.1 before treatment significantly decreased following oxygen therapy to 25.6 +/- 5.7, P < 0.05 and further declined following ASV treatment to 18.2 +/- 6.1, P < 0.01. No significant difference was shown in above percentages between day 14 of oxygen therapy and before treatment (P > 0.05). LVEF was significantly higher on day 14 of ASV treatment (37.2 +/- 4.1)% than on day 14 of oxygen therapy (33.2 +/- 5.1)% and before treatment (30.2 +/- 4.6)% (all P < 0.05). Six-minute walk distance was the shortest before treatment (226 +/- 28) m, longer on day 14 of oxygen therapy (289 +/- 26) m, and the longest on day 14 of ASV treatment (341 +/- 27) m (all P < 0.01). ASV treatment is of better efficacy and greater clinical significance in improvement of CHF by eliminating CSR than oxygen therapy.