Acute type B aortic dissection with communicating vs. non-communicating false lumen.

Background: In practice, patients with acute aortic dissection (AAD) are generally divided into 2 groups according to the status of the false lumen: non-communicating or communicating. The similarities and differences between the 2 groups, however, have not been fully determined in a large population. Methods and Results: We studied 502 patients with Stanford type B AAD. Clinical background at symptom onset was compared, and similarities and differences characterized, for patients with non-communicating (NC group, n=288) vs. communicating (C group, n=214) false lumens. Time of day (00.00-06.00 hours, 06.00-12.00 hours, 12.00-18.00 hours, and 18.00-24.00 hours) and extent of physical activity (extreme exertion, slight exertion, at rest, and sleeping) at symptom onset were similar between groups. Patients in the NC group were older (mean age, 71 +/- 11 years vs. 64 +/- 14 years, P<0.01) and had lower prevalence of distally extended aortic dissection (26% vs. 8%, P<0.01) and deaths in hospital (2% vs. 7%, P=0.011) than those in the C group. Conclusions: At symptom onset, clinical circumstances and physical activity were similar between the groups, and old age and a background of DeBakey IIIa aortic dissection may be associated with determination of false lumen status. The outcome in the NC group was better than in the C group.