People having surgery may be more likely to experience cardiovascular problems afterward when they have a common nighttime breathing disorder known as sleep apnea, a study suggests. Compared to patients without apnea, people with severe apnea were more than twice as likely to die of heart complications or experience serious cardiac events like heart attacks and strokes within 30 days of surgery, researchers report in JAMA.
Previous research suggests that sleep irregularities can increase the risks for a variety of cardiovascular disorders, such as clogged or hardened arteries, high blood pressure, irregular heartbeat, and stroke, as well as metabolic problems like high cholesterol, obesity and diabetes that all contribute to cardiovascular disease.
For the current study, researchers did sleep studies for 1,218 patients before they had surgery for conditions unrelated to heart disease. None of the patients had been previously diagnosed with apnea - which occurs when breathing repeatedly stops and starts during sleep - but two-thirds of them were found to have the condition based on their sleep study results.
"In patients with severe obstructive sleep apnea, there are repeated episodes of complete or partial airway obstruction during sleep," said lead study author Dr. Matthew Chan of the Chinese University of Hong Kong. "Patients having surgery are particularly vulnerable because the surgery and anesthetics are likely to worsen airway obstruction," Chan said by email. The type of anesthesia during the surgery didn't appear to influence the risk of heart complications afterwards. Use of opioids and oxygen therapy after surgery also didn't appear to impact the risk.