Non-uniform aortic medial degenerative changes associated with aortic valve disease

We read with interest the excellent article by Agozzino et al. [1], regarding the variable degree of aortic medial degenerative changes observed at the different aortic sinuses. They report more severe aortic medial degenerative changes above the non-coronary aortic sinus, as compared to the changes observed above the aortic sinus associated with the right coronary artery.

Ten of their 22 cases are categorized as ‘dystrophic calcific valve disease’. It would be of interest to know the breakdown of this group to determine the number of cases that were actually tricuspid degenerative valves and more importantly, how many were congenitally bicuspid aortic valves with degeneration.

This division of the data is of interest since congenitally bicuspid aortic valves are known to be associated with aortic medial disease (cystic medial necrosis), coarctation and congenital aortic arch abnormalities [2]. Investigators have postulated a common pathogenesis of aortic valve and aorta diseases, with evidence that the aortic valve and portions of the aorta may share a common embryonic origin [3]. In addition, echocardiographic observations by Pachulski and colleagues [4], demonstrated an association of aortic dilatation with congenitally bicuspid aortic valve in the absence of hemodynamic valvular abnormalities.

We previously studied the severity of aortic medial degenerative changes associated with stenotic congenitally bicuspid and tricuspid aortic valves in patients who died shortly after aortic valve replacement [5]. Interestingly, the aortic sections in our study were taken from the aorta above the right coronary cusp (right anterior, 2 cm from the sinotubular junction). Computer aided morphometry demonstrated that the aortas of congenitally bicuspid aortic valve patients had less elastic tissue than those of patients with tricuspid aortic valves.

In the study of Agozzino et al. [1], the aortic medial degeneration scores of aortic segments above the right aortic sinus, in Table 1, show variable scores, ranging from mild to severe. One wonders if the aortic medial degeneration score differs between tricuspid and bicuspid valves in the study group?

The findings of this valuable study [1] add to our increasing knowledge concerning the aortic root, which is now recognized to be a complicated asymmetrical structure. The preliminary protein data are important and future studies will be important.

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