Sleep‐disordered breathing in a general heart failure population: relationships to neurohumoral activation and subjective symptoms

Abstract

SUMMAR Y The aim of this study was to determine the prevalence of sleep-related breathing disorders (SDB) in a UK general heart failure (HF) population, and assess its impact on neurohumoral markers and symptoms of sleepiness and quality of life. Eighty-four ambulatory patients (72 male, mean (SD) age 68.6 (10) yrs) attending UK HF clinics underwent an overnight recording of respiratory impedance, SaO 2 and heart rate using a portable monitor (Nexan). Brain natriuretic peptide (BNP) and urinary catecholamines were measured. Subjective sleepiness and the impairment in quality of life were assessed (Epworth Sleepiness Scale (ESS), SF-36 Health Performance Score). SDB was classified using the Apnoea/Hypopnoea Index (AHI). The prevalence of SDB (AHI > 15 events h )1 ) was 24%, increasing from 15% in mild-to-moderate HF to 39% in severe HF. Patients with SDB had significantly higher levels of BNP and noradrenaline than those without SDB (mean (SD) BNP: 187 (119) versus 73 (98) pg mL )1 , P ¼ 0.02; noradrenaline: 309 (183) versus 225 (148) nmol/24 h, P ¼ 0.05).There was no significant difference in reported sleepiness or in any domain of SF-36, between groups with and without SDB (ESS: 7.8 (4.7) versus 7.5 (3.6), P ¼ 0.87). In summary, in a general HF clinic population, the prevalence of SDB increased with the severity of HF. Patients with SDB had higher activation of a neurohumoral marker and more severe HF. Unlike obstructive sleep apnoea, SDB in HF had little discernible effect on sleepiness or quality of life as measured by standard subjective scales.

Implications of Cheyne‐Stokes Breathing in Advanced Systolic Heart Failure

“…Previous reports of HF estimated a CSB prevalence of 30%-50%, a significantly lower range than in our study. 3,4 Since sleep disorder prevalence is correlated to HF severity, 5 it is conceivablethat our findings represent the true prevalence in such a cohort of patients with advanced disease. In most of the previous studies, 6 sleep apneas in HF patients were assessed by using polysomonography End-diastolic diameter (mm) 61±8 6 1 ±6 .…”

“…24 This thesis is supported by other observations, in which the ''smoking gun'' of CSB in HF is repeated episodes of hypoxemia with a contribution of ventricular arrhythmia and high sympathetic tone. 5,25,26 Moreover, several studies demonstrated that even short daytime oscillatory breathing patterns are associated with poor outcome. 27,28 The main, as yet unsolved, question is whether CSB is merely a reflection of HF disease severity or whether it actually causes the clinical course of the HF disease to deteriorate.…”

“…21 Although we cannot claim that CSB is a direct cause of mortality in HF patients, it is conceivable that repeated episodes of CSB may deteriorate HF disease over time. 5,25 Several study limitations should be noted. We recognize that our study is relatively small, based on a single night recording and we fully agree with others that further studies in this arena are needed.…”

Determinants of Behavioral Alertness in Adults with Heart Failure

“…3 Sleep disordered breathing was considered, even though prior studies indicate that daytime sleepiness is not explained by sleep apnea in these patients. [4][5][6][7] As this variable had missing data, it was analyzed both with available data and again after multiple imputations based on age, gender and BMI at baseline. Data were imputed using the method of chained equations as implemented in the Stata program ice command.…”

“…3 There is a growing awareness that sleep disturbances are common in HF and these symptoms are not explained by sleep disordered breathing. [4][5][6][7] Over half of HF patients report insomnia symptoms. 4 The most commonly reported problems are initiating and maintaining sleep; objective sleep assessments have shown shorter sleep duration, frequent arousals, and sleep stage changes in HF patients.…”