Continuous positive airway pressure in heart failure patients with obstructive sleep apnoea

Abstract
The aim of the study was to study the effect of 6 months of continuous positive airway pressure (CPAP) in community heart failure (HF) patients with obstructive sleep apnoea (OSA). Clinically stable outpatients with HF and OSA (left ventricular ejection fraction (LVEF) 15/h, n = 19) treated with CPAP and a control group (LVEF <45%, apnoea/hypopnoea index <10/h, n = 7) were compared at baseline and at 6 months by Minnesota heart failure score, Epworth sleepiness score, shuttle walk distance, brain natriuretic peptide, urinary catecholamines and echocardiographic indices using paired t-test, McNemar's tests and effect sizes. In HF patients with OSA, CPAP improved LVEF (35.9 +/- 6.1% to 40.6 +/- 8.0%, P = 0.015), decreased LV end-systolic volume (152 +/- 74 to 135 +/- 62 cm(3), P = 0.03), systolic blood pressure (P = 0.04) and sleepiness (Epworth sleepiness score 8.8 +/- 4.8 to 6.3 +/- 3.2, P = 0.01), whereas walk distance, catecholamines, brain natriuretic peptide levels and symptoms were unchanged. These outcomes did not change in the HF control group. In community HF patients with OSA, CPAP therapy over 6 months improved LVEF, systolic blood pressure and sleepiness, but not sympathetic activation, brain natriuretic peptide or exercise levels. Acceptance was relatively low, potentially limiting therapeutic effectiveness.