For individuals who have undergone angioplasty, a procedure that clears blocked heart arteries, untreated sleep breathing problems may increase risks of heart attack or stroke, researchers have reported.
In a new study published in the Journal of the American Heart Association on June 15, Toru Mazaki, from Kobe Central Hospital in Japan, and colleagues involved 241 patients who underwent angioplasty, some of whom had sleep disordered breathing such as snoring and sleep apnea.
Sleep apnea is a common but serious sleep disorder that occurs when breathing stops or becomes shallow during sleep. Those who have this condition repeatedly stop breathing during sleep which could lead to their brain and the rest of their body not getting enough oxygen.
Snoring, on the other hand, happens as a result of a partial blockage in the sinuses or other parts of the respiratory tract but it similarly reduces the amount of oxygen a person gets during sleep.
Using heart and respiratory monitors, the researchers observed the breathing of the patients who underwent angioplasty after they went through the procedure, also known as percutaneous coronary intervention (PCI).
Over an average of nearly six years, the researchers tracked the patients and found that 21 percent of those with sleep-disordered breathing suffered major heart events. The rate is far higher compared with the heart complication rate of just 8 percent in those who did not have sleep-disordered breathing problems.
The researchers likewise observed that those with sleep-disordered breathing had increased risk for death during the follow-up period.
"The study's results showed that the presence of SDB among patients with acute coronary syndrome following primary percutaneous coronary intervention is associated with a higher incidence of major adverse cardiocerebrovascular events during long‐term follow‐up," the researchers reported.
Mazaki explained that intermittent low-oxygen periods during sleep may worsen stress or set off inflammatory responses that can damage the heart.
He added that their findings suggest that sleep-disordered breathing, which has long been associated with cardiovascular risks and other symptoms such as elevated glucose, high blood pressure and abnormal heart rhythms, needs to be considered in patients with acute coronary syndrome after undergoing angioplasty
The result of the study suggests that doctors and patients should consider sleep studies after angioplasty to rule out sleep-ordered breathing. They can also take precautions to restore healthy breathing during sleep.
There is limited awareness on sleep disordered breathing among healthcare providers who care for angioplasty patients but experts said that the findings may hopefully encourage doctors to pay more attention to symptoms of awakening from sleep or fatigue.