Abstract 18095: Prognostic Impact of Sleep Duration and Sleep Efficiency on Mortality in Patients with Chronic Heart Failure
Context: Both short and long self-reported sleep duration has been linked to increased mortality risk. The underlying mechanisms for the mortality risk increase in long sleepers are unknown.
Objective: To test, whether long self-reported sleep duration is paralleled by impaired objectively measured sleep efficiency and to assess whether impaired sleep efficiency is an independent risk factor for death in patients with chronic heart failure (CHF). Hypotheses were formulated after data collection.
Design, Setting, Patients: Observational study of 211 consecutive CHF patients (age 63±10 years, 89% men, left ventricular ejection fraction 34±10%), who underwent polysomnography and completed standardized questionnaires between 1/2002 and 12/2009 at the University Hospital Regensburg.
Main Outcome: All cause mortality ascertained by medical documents. Follow-up was performed between 12/2009 and 01/2010 (mean follow-up time: 44±26 months).
Methods and Results: Comparison of objective sleep efficiency in CHF patients showed an inverse U-shaped relationship according to quintiles of self-reported sleep duration: Sleep efficiency in CHF patients from the highest quintile (≥9h of self-reported sleep duration) was significantly lower as compared to the middle quintile with 7.25-8h of self-reported sleep duration (71±15% versus 77±11%, p=0.032) and identical to the lowest quintile (≤5.75h of self-reported sleep duration; 71±15% versus 71±16%, p=0.950). Fifty-seven patients died during follow-up. Objective sleep efficiency, age, left ventricular ejection fraction and cause of CHF were identified as independent risk factors for all-cause mortality in a multivariate adjusted survival analysis (p<0.001, p=0.022, p=0.005 and p=0.002, respectively), while self-reported sleep duration did not influence mortality.
Conclusions: Objective sleep efficiency is significantly impaired in CHF patients with prolonged self-reported sleep duration compared to those with medium self-reported sleep duration, suggesting a misperception of sleep in these patients. In contrast to self-reported sleep duration, objective sleep efficiency predicts mortality in CHF patients independently from age, cardiac function and cause of CHF.
- © 2011 by American Heart Association, Inc.