Sleep apnea common among patients undergoing heart procedure

Patients undergoing percutaneous coronary intervention (PCI), a coronary artery widening procedureused to treat heart disease, are at high risk for obstructive sleep apnea (OSA), according to new research presented at the 2015 American Thoracic Society International Conference.

"Our findings, in a large, multicenter sample of patients, reinforce the known association between OSA and cardiovascular disease," said researcher Luciano Drager, MD, PhD, of the University of São Paulo School of Medicine in Brazil. "Nearly half of the patients in our study, who were treated with PCI for either myocardial infarctions or angina, had OSA."

The study included 1,305 mostly male patients from Singapore, China and Hong Kong, India, Myanmar, and Brazil who had undergone successful PCI. Overnight sleep studies were performed in all subjects.

The overall prevalence of OSA was 45%, and 21.8% of the study subjects had severe OSA, as assessed with the apnea-hypopnea index (AHI), which indicates OSA severity based on the number of apneas (complete cessation of airflow) and hypopneas (partial cessation of airflow) per hour of sleep.

Excessive daytime sleepiness, measured with the Epworth Sleepiness Scale, was observed in only a quarter of the patients with OSA. Similarly, only half of the patients with OSA were categorized as being at high risk for OSA on the Berlin Questionnaire, a sleep apnea screening tool, suggesting that these validated tools in the general population may not be useful for patients with cardiovascular diseases.

"Earlier studies have shown strong relationships between sleep apnea and a number of cardiovascular conditions, including high blood pressure, arrhythmia, stroke and heart failure," said Dr. Drager. "Our study supports this strong association between OSA and heart disease and also suggests that the methods used to screen for OSA in patients with cardiovascular disease need to be improved."

The ongoing study will evaluate whether OSA contributes to the risk of cardiovascular events in patients who have undergone successful PCI.