SEATTLE — There is no standard way to screen for sleep apnea in patients with heart failure, but there are several screening models to choose from, Dr. Steven M. Scharf said at the annual meeting of the Heart Failure Society of America.
Sleep apnea commonly accompanies heart failure, and can be treated, though there's little high-quality evidence that treatment alters mortality or quality of life. Still, “you certainly should screen all your heart failure patients,” said Dr. Scharf, professor of medicine and director of the sleep disorders lab at the University of Maryland, Baltimore.
One good clinical screening tool is the Berlin Questionnaire, which asks about symptoms in three categories: excessive sleepiness or sleepiness while driving; wild, disturbing snoring or gasping; and either obesity or heart failure (Ann. Intern. Med. 1999;131:485–91). Primary care patients with symptoms from two of the three categories have a high risk for obstructive sleep apnea, but the sensitivity and specificity of the Berlin Questionnaire in patients with heart failure is unknown, he said.
Other screening schemes stratify patients by neck circumference, with larger necks increasing the risk for sleep apnea (N. Engl. J. Med. 2002;347:498–91). Various other scoring systems combine clinical findings such as male gender, body mass index, a snoring index, and a choking index to rate the likelihood of sleep apnea. Many of these screening models may be useful, Dr. Scharf suggested.
If a heart failure patient seems to have a high probability of having sleep apnea (perhaps based on the Berlin Questionnaire and neck circumference), schedule a full polysomnograph evaluation, he advised.
Consider doing overnight pulse oximetry testing in heart failure patients who don't meet your threshold for high risk for apnea, he added. A recent meta-analysis of 79 studies that used pulse oximetry for screening suggests that if you have a strong clinical suspicion for obstructive sleep apnea and testing shows fewer than 15 desaturations per hour, diagnostic polysomnography may be warranted (Chest 2001;120:625–33). With more than 15 desaturations/hour, a full evaluation for sleep apnea or treatment with titrated continuous positive airway pressure may be reasonable.
Two articles suggest that an algorithm assessing heart rate variability might help screen for apnea in heart failure patients, but practice parameters don't exist and would need to be developed, he said (Eur. Respir. J. 2006;27:571–7).
One small study suggests the PAT100 Watch, which measures peripheral arterial tone, also might help screen for sleep apnea. Portable polysomnography (outside sleep labs) is not recommended by the American Thoracic Society and other organizations.
Dr. Scharf has no affiliation with companies that sell the tools he discussed.
Patients with symptoms from two of the three Berlin Questionnaire categories are at high risk for apnea. DR. SCHARF