By Marc E. Shelton, MD, FACC

Recent Cardiosurve results indicate that additional effort into the diagnosis and treatment of sleep disordered breathing may be needed. Although Somers, V. et al1 have indicated that more than 12 million Americans have sleep apnea, some estimate that as many as 85 percent of cases go undiagnosed and sleep apnea is typically diagnosed years or decades after its onset.

The March 2011 survey indicated that although cardiologists tend to believe that a much higher percentage of their patients suffer from sleep disorder breathing than are diagnosed or treated, only one to seven out of the approximately 300 patients seen per month are ever referred to sleep centers. Two out of three cardiologists surveyed did not include an assessment of sleep disorder breathing in patient workups. The reason for hesitancy is that 42 percent of cardiologists indicate a lack of satisfaction with the effectiveness of sleep apnea therapy and 29 percent of cardiologists believe that the cost of a sleep study is too high.

Unfortunately, sleep disorder breathing can be either causative or an exacerbant of a legion of significant cardiovascular problems, including systemic and pulmonary hypertension, heart failure, arrhythmias, stroke and MI. Approximately two out of three cardiologists believe that more than 20 percent of their patients with heart failure or atrial fibrillation have associated sleep apnea according to the survey. Common signs, symptoms, and risk factors for obstructive sleep apnea include disruptive snoring, witnessed apnea or gasping, obesity and/or enlarged neck size, and hypersomnolence. Other potential signs and symptoms include crowded appearing pharyngeal airway, increased blood pressure, morning headache, sexual dysfunction, and behavior changes. Diagnostic testing involves first considering the problem followed by initial diagnostic testing, which can include:

  1. questionnaires
  2. overnight oximetry
  3. home-based/ambulatory unattended polysonography
  4. overnight polysonography

Home-based polysonography seems to be catching on as a less expensive alternative to traditional sleep studies in some regions. Often the cardiovascular team is the first to identify the potential problem. The Cardiosurve survey indicates that a large majority (66 percent) of cardiologists consider referring patients to sleep centers/labs as their top diagnostic model, followed by referral to pulmonologists (52 percent). Only one out of three cardiologists in the survey would consider using the home diagnostic tool in their practice.

Given the hesitancy regarding patient diagnosis and treatment by many cardiologists, it would seem that a good strategy would be for practices to review their own local patterns and to try to improve facilitation of referrals to interested pulmonologists or other cardiologists that have a particular interest in the area of sleep medicine.

Unfortunately with the obesity epidemic in the United States (65 percent of Americans overweight or obese and 33 percent of Americans are frankly obese), it is certain that the incidence of sleep apnea will increase. Sleep apnea is an ideal candidate disease for a care integration project. Hopefully, continued discussion about this important problem will help us to improve our clinical approaches.


Dr. Shelton is president of Prairie Cardiovascular Consultants, Ltd., in Springfield, IL.

Reference

  1. Somers V. et al. Sleep Apnea and Cardiovascular Disease: An American Heart Association/American College of Cardiology Foundation Scientific Statement From the American Heart Association Council for High Blood Pressure Research Professional Education Committee, Council on Clinical Cardiology, Stroke Council, and Council on Cardiovascular Nursing In Collaboration With the National Heart, Lung, and Blood Institute National Center on Sleep Disorders Research (National Institutes of Health). Circulation 2008;118;1080-1111.