SAN DIEGO — The presence of obstructive sleep apnea independently increases the risk of death after acute ischemic stroke, results from a single-center study showed.
The finding underscores the importance of screening for obstructive sleep apnea (OSA) as a risk factor for the development of stroke, since effective treatment for the condition is available, researchers led by Dr. Meghna P. Mansukhani reported during a poster session at the International Stroke Conference.
The finding also confirms results of a 10-year Swedish study that demonstrated an increase in mortality in stroke patients diagnosed with OSA after the stroke by polysomnography (Arch. Intern. Med. 2008;168:297–301).
For the study, Dr. Mansukhani and her colleagues in the departments of family medicine, emergency medicine, and cardiovascular diseases at the Mayo Clinic, Rochester, Minn., studied 174 consecutive patients who presented with acute ischemic stroke during June 2007–March 2008. The patients were asked to complete the Berlin Sleep Questionnaire, a simple instrument that has been shown to have good sensitivity and specificity as a screening test for OSA in the primary care setting.
The mean age of the patients was 72 years, and 55% were female.
The three most common stroke subtypes were cardioembolic (33%), large vessel disease (27%), and undetermined etiology (27%).
A total of 105 patients (61%) had a high risk of sleep apnea on the basis of their responses to the Berlin Sleep Questionnaire. Of these, seven had a previous diagnosis of OSA, and there was no difference by gender or age in the prevalence of high or low risk for OSA.
Of the 174 patients studied, 11 died (6%). Those who had a previous diagnosis of OSA were 5 times more likely to die within the first month following the stroke, compared with those who did not have a diagnosis of OSA.
“We were trying to establish whether there was an increase in mortality in patients at risk of or with previous diagnosis of OSA in our cohort, and indeed, the study did confirm this,” Dr. Mansukhani said in an interview after the conference, which was sponsored by the American Heart Association.
Limitations of the study, she added, included the fact that “there could be potential confounders such as diabetes mellitus that were not accounted for and that may have biased the results.”
Dr. Mansukhani said she had no conflicts to disclose.
'There was an increase in mortality in patients at risk of or with previous diagnosis of OSA in our cohort.' DR. MANSUKHANI