A congenitally malformed aortic valve, unicuspid (UAV) or bicuspid (BAV), occurs in about 1% of the population and is known to be more frequent in patients with aortic dissection. The clinical and operative findings in a series of 134 patients with spontaneous, acute Type A aortic dissection (TAAD) were studied, comparing patients with normal and abnormal aortic valve morphology. The aortic valve was normal in 123/134 (92%) patients and abnormal in 11/134 (8%) patients: BAV in 10/134 (7.5%) and UAV in 1/134 (0.7%). Demographics were similar between groups except for a lower frequency of systemic hypertension in the UAV/BAV group (46 vs. 82%, p<0.01). Penn class stratification was also similar in the 2 groups. The UAV/BAV group had a greater frequency of aortic root enlargement (64 vs. 18%, p<0.01) and a larger median root diameter (5.7 vs. 4.6cm, p=0.02). In the UAV/BAV group, the entry tear was more frequently in proximal (intrapericardial) zone 0 (91 vs. 62%, p=0.049). The frequency of abnormal aortic media histology was similar. The rate of root replacement was higher in the UAV/BAV group and early mortality was similar. The frequency of congenitally malformed aortic valve in this series was 8x the normal population. The one UAV in the series was the only severely stenotic valve. In TAAD patients with a congenitally malformed valve, aortic root aneurysm was more common and the entry tear was nearly always proximal.
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