Contrasting histoarchitecture of calcified leaflets from stenotic bicuspid versus stenotic tricuspid aortic valves

Abstract

Preliminary findings from clinical trials of percutaneous balloon aortic valvuloplasty and intraoperative debridement of calcific deposits in patients with aortic stenosis have suggested that calcified, congenitally bicuspid aortic valves may be less amenable to these techniques than are calcified tricuspid aortic valves. Accordingly, we evaluated the histoarchitecture of calcific deposits in 30 operatively excised aortic valves. Light microscopic sections taken through the calcified aortic valve leaflets disclosed two principal types of histoarchitecture. In 11 aortic valves nodular calcific deposits were superimposed on an underlying fibrotic aortic valve leaflet (type A); in 17 valves calcific deposits were diffusely distributed throughout the body (spongiosa) of the aortic valve leaflets (type B). Two aortic valves could not be classified histologically. These histologic subtypes were not randomly distributed with regard to gross valvular morphology. All 14 bicuspid valves (100%) were type B; in contrast, 11 (69%) of 16 tricuspid aortic valves were type A, and only 3 (19%) of 16 tricuspid valves were type B (p less than 0.01). Both valves with nonclassifiable histologic features were tricuspid on the basis of gross examination. Thus, the histoarchitectural distribution of calcific deposits is different for bicuspid than for tricuspid stenotic aortic valves. The more diffuse distribution of calcium throughout the body of calcified bicuspid aortic valve leaflets may render these valves less amenable to operative and percutaneous valvuloplasty than are calcified tricuspid aortic valve leaflets on which calcific deposits are typically superimposed in nodular form.

Inflammatory Characteristics of Stenotic Aortic Valves: A Comparison between Rheumatic and Nonrheumatic Aortic Stenosis

“…Whereas NRAS-T mostly revealed calcification localised at the base of the cusps, NRAS-B valves as well as RAS valves revealed a significant higher proportion of diffuse calcification. The difference in calcification between NRAS-B and NRAS-T is previously described by Isner et al [29]. They investigated 30 heavily calcified aortic valves and found nodular calcific deposits in 11/16 NRAS-T and diffuse calcification in 14/14 NRAS-B.…”

T lymphocyte infiltration in non-rheumatic aortic stenosis: a comparative descriptive study between tricuspid and bicuspid aortic valves

“…These differences in the localisation of calcification between tricuspid and bicuspid stenotic aortic valves were described by Isner and colleagues in 1990. 31 One possible conclusion from these results could be that primary degenerative calcification of normal tricuspid aortic valves and secondary calcification of congenital bicuspid valves are not two separate entities. Perhaps the greater degree of cusp anomaly in the bicuspid valve explains the increased cusp calcification and cusp thickening in that situation.…”

Comparison of multislice computed tomography findings between bicuspid and tricuspid aortic valves before and after transcatheter aortic valve implantation

“…TAVI in BAV has been considered to be an off‐label indication because of the risk of PVL and poor hemodynamic function due to uneven expansion of the transcatheter valve resulting from asymmetry of the valve orifice and annulus, heavily calcified leaflets, and calcification of the raphe. A previous report showed that the histoarchitectural distribution of calcific deposits varies between bicuspid and tricuspid stenotic aortic valves, and a more diffuse pattern of calcium distribution was observed in bicuspid aortic valves leaflets . The degree of aortic valve calcification was a predictive factor of adverse clinical outcome after surgical aortic valve replacement or conservative treatment .…”