Severe sleep apnea during REM sleep tied to acute CV events

(HealthDay)—Severe obstructive sleep apnea (OSA) that occurs during REM sleep is associated with recurrent cardiovascular events in those with pre-existing cardiovascular disease, according to a study published in the March 1 issue of the American Journal of Respiratory and Critical Care Medicine.

R. Nisha Aurora, M.D., from Johns Hopkins University in Baltimore, and colleagues examined the association between OSA during REM sleep and a composite cardiovascular end point over an average of 9.5 years of follow-up in participants of the Sleep Heart Health Study with and without prevalent cardiovascular disease. Only those with a non-REM apnea-hypopnea index (AHI) of <5.0 events/hour were included.

The researchers found that the adjusted hazard ratio (HR) for the composite cardiovascular end point among the 180 with severe REM OSA (≥30 events/hour) was 1.35 (95 percent confidence interval, 0.98 to 1.85), compared to the reference group of REM AHI <5.0 events/hour (1,758 patients). The finding was strengthened in those with prevalent cardiovascular disease and severe OSA during REM sleep (adjusted HR, 2.56; 95 percent confidence interval, 1.46 to 4.47).

"Severe OSA that is present only during REM sleep is associated with recurrent cardiovascular events in people who have prevalent cardiovascular disease," the authors write.