Impact of Adaptive Servo-Ventilation on Cardiovascular Function and Prognosis in Heart Failure Patients with Preserved Left Ventricular Ejection Fraction and Sleep-Disordered Breathing

AIMS: Effective pharmacotherapy for heart failure with preserved left ventricular ejection fraction (HFpEF) is still unclear. Sleep-disordered breathing (SDB) causes cardiovascular dysfunction, giving rise to factors involved in HFpEF. However, it remains unclear whether adaptive servo-ventilation (ASV) improves cardiovascular function and long-term prognosis of patients with HFpEF and SDB. METHODS AND RESULTS: Thirty-six patients with HFpEF (LVEF >50%) and moderate to severe SDB (apnoea-hypopnoea index >15/h) were enrolled. Study subjects (LVEF 56.0%, apnoea-hypopnoea index 36.5/h) were randomly assigned to two groups: 18 patients treated with medications and ASV (ASV group) and 18 patients not treated with ASV (non-ASV group). NYHA class, cardiac function including LVEF, left atrial volume index (LAVI), E/E', vascular function including flow-mediated dilatation (FMD) and cardio-ankle vascular index (CAVI), and levels of BNP and troponin T were determined at baseline and 6 months later. Patients were followed to register cardiac events after enrolment (follow-up 543 days). ASV therapy improved cardiac diastolic function and decreased CAVI and BNP (NYHA class, 2.3 to 1.5; LAVI, 48.6 to 42.6 mL/m(2); E/E', 12.8 to 7.1; CAVI, 9.0 to 7.7; BNP, 121.5 to 58.1 pg/mL, P < 0.0125, respectively). LVEF, FMD, and troponin T did not change significantly in either group. Importantly, the event-free rate was significantly higher in the ASV group than in the non-ASV group (94.4% vs. 61.1%, log-rank P < 0.05). CONCLUSION: ASV may improve the prognosis of HFpEF patients with SDB, with favourable effects such as improvement of symptoms, cardiac diastolic function, and arterial stiffness. ASV may be a useful therapeutic tool for HFpEF patients with SDB.