NEW YORK (Reuters Health) — About one quarter of heart failure patients have moderate-to-severe obstructive sleep apnea and they also have significantly higher death rates than those without sleep apnea, Canadian researchers report.Obstructive sleep apnea is a common problem that typically occurs when soft tissues in the back of the throat temporarily block off airflow during sleep. During sleep, it is not uncommon for patients to have numerous periods of absent breathing lasting for several seconds each. The perpetual lack of adequate sleep can also impair quality of life.

Dr. Hanqiao Wang and colleagues at the University of Toronto in Ontario conducted a study of 164 patients who were referred to the Heart Failure Clinic of Mt. Sinai Hospital between 1997 and December 2004. Standard sleep tests were performed to diagnose sleep apnea.

As reported in the Journal of the American College of Cardiology, the investigators identified 37 patients with untreated moderate-to-severe sleep apnea, 14 patients with treated disease, and 113 without sleep apnea or mild disease that did not require treatment.

The authors found that patients with sleep apnea were roughly twice as likely to die over the three-year study period as those without the condition.

Wang and colleagues conclude that their findings “provide a strong rationale for conducting a large-scale, randomised trial to determine whether treating sleep apnea in patients with heart failure improves survival.”