Recent medical research has found a correlation between untreated sleep apnea and increased deaths of heart failure patients.
In a seven-year study conducted by New York’s Mt. Sinai Hospital and Sleep Research Laboratories at Toronto General Hospital, heart failure patients with untreated sleep apnea are twice as likely to die. They found that people with obstructive sleep apnea (OSA) who did not receive treatment had a death rate of 24%, compared to a death rate of 12% for patients with no sleep apnea and zero for people with OSA who were placed on a continuous positive airway pressure (CPAP) machine.
"Because OSA can be a severe physiological challenge to the body, it can certainly put extra stress on a heart that is already abnormal," explains Chris Brown, M.D., Medical Director of The Physician Foundation at California Pacific Medical Center’s (PFCPMC) Sleep Health Center. "People with sleep apnea have hundreds of respiratory events each night, which result in a drop in oxygen and a release of catecholamines, the body's adrenaline. Low oxygen requires the heart to pump harder – like exercising, only worse – and the release of catecholamines is known to cause structural damage to the heart muscle."
"If you improve oxygenation by using a CPAP, you are less likely to have negative outcomes," surmises Ernest Haeusslein, MD, Medical Director of CPMC’s Heart Failure and Transplant Program. "I hope this study will convince physicians that it is worth getting a sleep study performed to rule out sleep apnea in heart failure patients. An earlier diagnosis is better because that means you can begin the treatment earlier."
“That’s the most important take home message given the compelling trend seen in this study. I would not wait to rule out obstructive sleep apnea.”
One problem the study researchers found is that most heart failure patients do not have the usual symptoms of OSA – loud snoring, restless sleep, daytime sleepiness, morning headaches – which means the problem goes undetected unless a sleep study is performed.
Explains Brown: “Heart failure patients are already potentially impaired – they already don’t feel as good, they already may be a bit more tired or fatigued, they may require napping during the day – and they may blame some of these symptoms on heart failure, not apnea.”
“Symptoms can be confusing,” agrees Haeusslein. “When a patient comes in and complains about these symptoms and they have heart failure, if they are not obese, you may not think it is related to OSA. This research tells me we need to be more aggressive at ruling out sleep apnea in the heart failure population.”
“This research certainly suggests that cardiologists should screen for signs and symptoms of sleep apnea,” says Brown. “If they are not sure, they should order a sleep study or send the patient to a sleep specialist. Not only should a cardiologist ask if a patient snores or stops breathing at night, but they should look at the patient’s throat and body shape. A short, fat neck or receding jaw are all characteristics that lead to a narrow airway. In the throat, a long soft palette, large tonsils, long uvula and big tongue can also lead to a narrow air passageway – which in turn causes sleep apnea.”
Patients also need to take some responsibility, says Brown. “If you have high blood pressure or heart failure, it is very appropriate to ask your doctor if sleep apnea is something that might be of concern – especially if you are overweight and/or have snoring, pauses in breathing or daytime sleepiness. Ask to have a sleep study.”
“What’s called for is a randomized study with a large number of patients,” says Haeusslein. “However, I don’t want to wait until a more conclusive study is completed if I can benefit my patients now. Plus, wearing a CPAP to treat sleep apnea has virtually no risk – it only has potential benefits.”