Different Calcification Patterns of Tricuspid and Bicuspid Aortic Valves and Their Clinical Impact

Background: Mechanical strain plays a major role in the development of aortic calcification. Tissue subjected to major mechanical strain is a predilection site for the onset of osteoblastic activity. We hypothesized that (1) valvular calcifications are most pronounced at the localizations subjected to the highest mechanical strain and (2) calcification patterns are different in patients with bicuspid and tricuspid aortic valves.

Method: Multi slice computed tomography (MSCT) scans of 101 patients with severe aortic stenosis were analyzed using a 3D-post processing software allowing the quantification of calcification of tricuspid (TAV, n = 51) and bicuspid (BAV, n = 50) aortic valves. BAV and TAV patients were matched for age, gender, the major CV risk factors, and other comorbidities. Annular calcifications were carefully separated from free-leaflet edge calcification, and calcification volumes of every single cusp were quantified separately. Clinical follow-up for survival was assessed after a median of 2.3 years.

Results: BAV and TAV showed significant differences in calcification patterns. Bicuspid aortic valves exhibited higher calcification volumes (1,007 mm³ [IQR: 470–1,283] vs. 825 mm³ [IQR: 306–853], p = 0.014). Moreover, BAV showed increased calcification of the noncoronary cusp (NCC) (433 mm³ [IQR: 161–594] vs. 341 mm³ [IQR: 108–385], p = 0.018) and significantly higher calcification of the free leaflet edge (529 mm³ [IQR: 251–678] vs. 361 mm³ [IQR; 107–344], p < 0.001). The NCC showed the highest calcium load compared with the other leaflets (386 mm³ [IQR: 140–434] vs. 270 mm³ [IQR: 95–317] vs. 259 mm³ [IQR: 80–301], p = 0.045). Patients with annular calcification above the median had an impaired survival compared with patients with low annular calcification (p = 0.009), whereas calcification of the free leaflet edge was not predictive (p = 0.53).

Conclusion: Calcification patterns are different in aortic stenosis patients with bicuspid and tricuspid aortic valves. Patients with high annular calcification but not free leaflet edge have an impaired prognosis.

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Publikationsverlauf

Artikel online veröffentlicht:
03. Februar 2022