Painless Type B Aortic Dissection: Insights From the International Registry of Acute Aortic Dissection.

INTRODUCTION The classical presentation of a patient with Type B acute aortic dissection (TBAAD) is characterized by severe chest, back, or abdominal pain, ripping or tearing in nature. However, some patients present with painless acute aortic dissection, which can lead to a delay in diagnosis and treatment. We utilized the International Registry on Acute Aortic Dissections (IRAD) database to study these patients. METHODS We analyzed 43 painless TBAAD patients enrolled in the database between January 1996 and July 2012. The differences in presentation, diagnostics, management, and outcome were compared with patients presenting with painful TBAAD. RESULTS Among the 1162 TBAAD patients enrolled in IRAD, 43 patients presented with painless TBAAD (3.7%). The mean age of patients with painless TBAAD was significantly higher than normal TBAAD patients (69.2 versus 63.3 years, P = 0.020). The presence of atherosclerosis (46.4% versus 30.1%, P = 0.022), diabetes (17.9% versus 7.5%; P = 0.018), and other aortic diseases (8.6% versus 2.3%, P= 0.051), such as prior aortic aneurysm (31% versus 18.8% P = 0.049) was more common in these patients. Median delay time between presentation and diagnosis was longer in painless patients (median 34.0 versus 19.0 hours; P = 0.006). Dissection of iatrogenic origin (19.5% versus 1.3%; P < 0.001) was significantly more frequent in the painless group. The in-hospital mortality was 18.6% in the painless group, compared with an in-hospital mortality of 9.9% in the control group (P = 0.063). CONCLUSION Painless TBAAD is a relatively rare presentation (3.7%) of aortic dissection, and is often associated with a history of atherosclerosis, diabetes, prior aortic disease including aortic aneurysm, and an iatrogenic origin. We observed a trend for increased in-hospital mortality in painless TBAAD patients, which may be the result of a delay in diagnosis and management. Therefore, physicians should be aware of this relative rare presentation of TBAAD.