Left atrial enlargement tied to OSA in older Swedish men

Last Updated: 2017-09-08

By Rita Buckley

NEW YORK (Reuters Health) - Left atrial enlargement was independently associated with the prevalence and severity of obstructive sleep apnea (OSA) in a group of 71-year-old Swedish men, according to a new study.

Dr. Henrik Holtstrand Hjaelm from the University of Gothenburg and colleagues analyzed data from participants in The Study of Men Born in 1943, a longitudinal study of a random sample of men living in Gothenburg; 411 of these men underwent an overnight polygraphic sleep test at home and a standardized echocardiographic examination in 2014.

Moderate to severe OSA (apnea-hypopnea index score 15 or higher) was identified in 29% of the men. This subgroup had a higher frequency of systolic heart failure, hypertension, overweight and waist circumference, as well as a larger left atrial area (23.7 cm2 vs. 21.6 cm2, P<0.001) compared to men with mild or no OSA.

Linear regression indicated that OSA was significantly associated with left atrial enlargement after adjustment for overweight, atrial fibrillation, heart failure with reduced ejection fraction, hypertension and mitral regurgitation. Compared to men without OSA, mean left atrial area was 1.7 cm2 larger in men with moderate OSA (P<0.05).

"Research on the interaction between OSA and cardiovascular disease is very important," said Dr. Khalid Ismail, director of the Center for Sleep Medicine at Tufts Medical Center in Boston, who was not involved in the study.

In an email to Reuters Health, Dr. Ismail said that if the new results are confirmed in larger studies in more-diverse populations, an echocardiogram to assess left atrial enlargement might be indicated in patients with moderate to severe OSA.

"With early identification and intervention with CPAP therapy, better blood pressure control might delay the progression of atrial enlargement and improve patients' prognoses," he said.

Dr. Matt Bianchi, chief of the Division of Sleep Medicine at Massachusetts General Hospital, also in Boston, cautioned that "cross-sectional studies like this can't address causality."

He added that home testing underestimates the severity of sleep apnea and that the population demographics were limited in race, age and sex. The data on treating OSA to improve heart failure are mixed, he said.

"The way forward would be to randomize patients with left atrial enlargement and obstructive sleep apnea to CPAP or not CPAP, and see if any cardiac outcomes improved," Dr. Bianchi, who was not involved in the study, told Reuters Health by email.

He said he wasn't sure how important the specific question of atrial enlargement is compared with heart failure, atrial fibrillation and other cardiac outcomes.

Dr. Hjaelm did not respond to requests for comment.

SOURCE: http://bit.ly/2vKPb9P

J Sleep Res 2017.