Prevalence of Sleep-Disordered Breathing-Related Symptoms in Patients with Chronic Heart Failure and Reduced Ejection Fraction.

BACKGROUND: Sleep-disordered breathing (SDB) is highly prevalent in patients with chronic heart failure (CHF) and is associated with a poor prognosis. Data on SDB-related symptoms and vigilance impairment in patients with CHF and SDB are rare. Thus, the objective of the present study was to assess a wide spectrum of SDB-related symptoms and objective vigilance testing in patients with CHF with and without SDB. METHODS: Patients with CHF (n = 222; average age, 62 years; left ventricular ejection fraction [LVEF], 34%) underwent polysomnography regardless of the presence or absence of SDB-related symptoms. Patients were stratified into those with no SDB (apnea-hypopnea index [AHI] < 15 episodes/h), moderate SDB (AHI ≥ 15 to < 30 episodes/h), and severe SDB (AHI ≥ 30 episodes/h). A standardized institutional questionnaire assessing a wide spectrum of SDB-related symptoms was applied. A subset of patients underwent objective vigilance testing (Quatember Maly, 100 stimuli within 25 minutes). RESULTS: Daytime fatigue (no SDB, moderate SDB, and severe SDB: 53%, 69%, and 80%, respectively; P = 0.005), unintentional sleep (9%, 15%, and 32%, respectively; P = 0.004), and xerostomia (52%, 49%, and 70%, respectively; P = 0.018), as well as an impaired objective vigilance test result (mean reaction time, 0.516, 0.497, and 0.579 ms, respectively; P < 0.001) occurred more frequently with increasing severity of SDB. Seventy-eight percent of patients with CHF and SDB had at least 3 SDB-related symptoms. In a linear multivariable regression model, the frequency of daytime fatigue (P = 0.014), unintentional sleep (P = 0.001), xerostomia (P = 0.016), and mean reaction time (P = 0.001) were independently associated with increasing AHI independent of age, body mass index, New York Heart Association functional class, and LVEF. CONCLUSIONS: The majority of patients with CHF and SDB have several potential SDB-related symptoms and objective impairment of vigilance as potential treatment targets.

Prognostic impact of sleep duration and sleep efficiency on mortality in patients with chronic heart failure.

BACKGROUND: Both short and long self-reported sleep duration (SDSR) has been linked to increased mortality. Our analysis tested the hypothesis that long SDSR is paralleled by impaired objective sleep efficiency (SEPSG) measured by polysomnography (PSG) and that impaired SEPSG is a risk factor for death in patients with chronic heart failure (CHF). METHODS: SDSR and SEPSG were assessed by standardized questionnaire and PSG in 188 consecutive CHF patients (age range, 63±10 year; left ventricular ejection fraction, 34±10%) admitted to the Sleep Center of the University Hospital Regensburg between 1/2002 and 12/2009. The mean follow-up period was 44±26 months. RESULTS: SEPSG in CHF patients from the highest quintile of SDSR (≥9h) was significantly lower compared with the middle quintile (7.25-8h; 71±15% vs 77%±11%; p=0.032) and similar to the lowest quintile (≤5.75h; 71±15% vs 71±16%, p=0.950). SEPSG is an independent predictor for death in the multivariable model after accounting for the significant confounders age, left ventricular ejection fraction, cause of CHF, and NYHA class (hazard ratio [HR] per 5% increase, 0.85; 95% confidence interval [CI], 0.77-0.93; p<0.001). CONCLUSIONS: Data indicate that subjective long sleepers with CHF have poor sleep efficiency. Objectively measured SEPSG strongly predicts mortality in CHF patients, underscoring the importance of objective assessment of sleep.