Obstructive sleep apnea in patients with acute aortic dissection.

BACKGROUND

Obstructive sleep apnea (OSA) imposes an afterload burden on the left ventricle and increases the pressure gradient across the aortic wall. Thus, OSA may increase the risk for aortic dissection (AD).

METHODS

This study enrolled 40 subjects with acute AD from four institutions; 37 completed the modified Berlin Questionnaire and 31 underwent attended overnight polysomnography. Aortic diameter was measured on a computed tomography scan at seven locations from the sinotubular junction to the diaphragm.

RESULTS

Twenty-seven subjects had type A dissection; 13 had type B. In those who had polysomnography apnea-hypopnea index (AHI) ranged from 0.7 to 89. Prevalence of OSA (AHI ≥ 5) was 61%. Nocturnal presentation (10 p.m.-7 a.m.) did not differ by presence/absence of OSA. The modified Berlin Questionnaire was not predictive of the presence of OSA. Among type A subjects with polysomnography (n = 23), aortic diameters at all locations were greater in the OSA group though differences were not statistically significant. Summating aortic diameters at the seven locations also yielded a numerically larger mean value in the OSA group versus the non-OSA group.

CONCLUSIONS

In this sample of patients with acute dissection, OSA was prevalent but was not associated with a nocturnal presentation. The presence of underlying OSA may be associated with larger aortic diameters at the time of dissection compared to patients without OSA. Though differences did not meet statistical significance the current series is limited by small numbers.