Heart failure patients with untreated sleep apnea are more likely to die than those without this sleep disorder, says a study to be published in the Journal of the American College of Cardiology.
The study followed 164 patients with heart failure for more than seven years, and found that those with obstructive sleep apnea (OSA) had double the death rate of those patients who did not have sleep apnea.
Of the 37 patients with untreated OSA, the death rate was 24% in contrast to 12% for the 113 patients with no sleep apnea.
Obstructive sleep apnea is common in patients with heart failure, and contributes to increased blood pressure, heart rate and other cardiac disturbances. The study, ?Influence of Obstructive Sleep Apnea on Mortality in Patients With Heart Failure,? will be published in the April 17, 2007 edition of the prestigious Journal of the American College of Cardiology. This is the first time that the effect of obstructive sleep apnea on mortality rates of heart failure patients has been studied and reported.
?The vast majority of heart failure patients across North America are not being assessed for the diagnosis of sleep apnea and, as a result, are not being treated for it. Our data says that many of these patients need to be treated for this disorder and that this will have a significant impact on their survival,? said Dr. Douglas Bradley, Head of the Sleep Research Laboratories at Toronto General Hospital, Toronto Rehabilitation Institute, and Mount Sinai Hospital, and Director of the University of Toronto Centre for Sleep Medicine and Circadian Biology.
Obstructive sleep apnea occurs when a person stops breathing during sleep at least 15 to 20 times an hour. These recurrent interruptions in breathing deprive the brain of oxygen and activate the sympathetic nervous system, causing increases in blood pressure, heart rate and other disturbances. This, in turn, contributes to the progression of heart failure and mortality.
The research also suggests that there is a strong trend to a reduced death rate for the patients with OSA who were treated with a device called continuous positive airway pressure (CPAP). The device applies air pressure via a mask placed over the nose during sleep. The continuous air pressure flows through the nose into the throat, propping it open and preventing it from collapsing during sleep. This allows a person to breathe without interruptions.