Adaptive servoventilation versus oxygen therapy for sleep disordered breathing in patients with heart failure: a randomised trial

Abstract

Background: Both adaptive servoventilation (ASV) and nocturnal oxygen therapy improve sleep disordered breathing (SDB), but their effects on cardiac parameters have not been compared systematically.

Methods and results: 43 patients with chronic heart failure (CHF; left ventricular ejection fraction (LVEF) ≤50%) with SDB were randomly assigned to undergo ASV (n=19, apnoea hypopnoea index (AHI)=34.2±12.1/h) or oxygen therapy (n=24, 36.9±9.9/h) for 3 months. More than 70% of SDB events in both groups were central apnoeas or hypopnoeas. Although nightly adherence was less for the ASV group than for the oxygen group (4.4±2.0 vs 6.2±1.8 h/day, p<0.01), the improvement in AHI was larger in the ASV group than in the oxygen group (-27.0±11.5 vs -16.5±10.2/h, p<0.01). The N-terminal pro-brain natriuretic peptide (NT-proBNP) level in the ASV group improved significantly after titration (1535±2224 to 1251±2003 pg/mL, p=0.01), but increased slightly at follow-up and this improvement was not sustained (1311±1592 pg/mL, p=0.08). Meanwhile, the level of plasma NT-proBNP in the oxygen group did not show a significant change throughout the study (baseline 1071±1887, titration 980±1913, follow-up 1101±1888 pg/mL, p=0.19). The significant difference in the changes in the NT-proBNP level throughout the study between the 2 groups was not found (p=0.30). Neither group showed significant changes in echocardiographic parameters.

Conclusions: Although ASV produced better resolution of SDB in patients with CHF as compared with oxygen therapy, neither treatment produced a significant improvement in cardiac function in the short term. Although we could not draw a definite conclusion because of the small number of participants, our data do not seem to support the routine use of ASV or oxygen therapy to improve cardiac function in patients with CHF with SDB.

Trial registration number: NCT01187823 (http://www.clinicaltrials.gov).

Keywords: Adaptive Servo Ventilation; Chronic Heart Failure; Nocturnal Oxygen Therapy; Sleep Disordered Breathing.

Figure 1

Trial design. ASV, adaptive servo ventilation.

Figure 2

(A and B) Changes in the apnoea hypopnoea index (AHI) and 3% oxygen desaturation index (ODI) from baseline to treatment titration and 3 months of therapy: full analysis set. Plotted line graphs indicate the mean±SE at each assessment. *One-way repeated measure analyses of variance (ANOVA) showed that both adaptive servoventilation (ASV) and oxygen therapy significantly decreased AHI (ASV: baseline 34.2±12.1, titration 10.0±10.2, follow-up 7.2±5.9/h, p<0.01; oxygen: baseline 36.9±9.9, titration 19.5±11.0, follow-up 19.4±8.4/h, p<0.01) and 3% ODI (ASV: baseline 28.2±15.6, titration 3.0±2.4, follow-up 3.9±4.1/h, p<0.01; oxygen: baseline 32.7±11.9, titration 3.3±5.6, follow-up 2.6±5.7/h, p<0.01) within the same group. †Two-way measured ANOVA showed that a significant difference was found in the changes in AHI (p=0.01) but not in 3% ODI (p=0.56) throughout the study between the two groups.

Figure 3

Changes in the plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) level from baseline to treatment titration and 3 months of therapy: full analysis set. Plotted line graphs indicate the mean±SE at each assessment. The changes in NT-proBNP level throughout the study were compared by one-way and two-way repeated measure analyses of variance with post hoc pairwise comparison within the same group and between the two groups, respectively, after NT-proBNP values were log-transformed. *In the adaptive servoventilation group, the plasma NT-proBNP level decreased significantly from baseline to titration (1535±2224 to 1251±2003 pg/mL, p<0.01). At 3 months, it increased slightly and its change from baseline did not reach statistical significance (1311±1592 pg/mL, p=0.08). On the other hand, the oxygen group did not show a significant change throughout the study (baseline 1071±1887, titration 980±1913, follow-up 1101±1888 pg/mL, p=0.19). †The difference in the change in NT-proBNP throughout the study between the two groups did not reach statistical significance (p=0.30).