Sleep apnea in carotid stenosis

Sleep apnea is associated with advanced atherosclerosis. This study was focused on sleep breathing in patients with hemodynamically significant carotid stenosis, currently free from clinical symptoms.

17 patients with carotid artery stenosis of 70% and more in the absence of actual neurological symptoms indicated for non-acute endarterectomy, and 17 age- and sex-matched controls were examined using sleep polygraphy. 12 patients had a follow-up sleep polygraphy a month after the surgery.

The criteria of obstructive sleep apnea (OSA) were met by 4 patients prior to operation, by 2 patients after the operation, and by 2 control subjects. The pre-surgery apnea/hypopnea index (AHI) was 14 (+/-SD=17.0), post-surgery 8.3 (+/-9.0) and in the controls 6.7(+/-6.7). The pre-surgery oxygen desaturation index was 20.1 (+/-17.7), post-surgery 15.0 (+/-12.0) and in the controls 11.6 (+/-6.1). A comparison between the pre-surgery results seen in the patients and in controls after adjustment for BMI revealed no significant difference. The only significant difference between the pre-surgery and post-surgery values was found in the AHI (P=0.045).

According to this study there exists an association between carotid stenosis and OSA, however this association is explainable by a higher BMI. The study also found a tendency toward OSA alleviation in response to endarterectomy.