Histological analysis of human aortic valves identified two distinct calcification phenotypes ('intrinsic' and 'nodular'), with calcification present in all samples from individuals >50 years old.
Observational
Two distinct phenotypes of aortic valve calcification ('intrinsic' and 'nodular') exist, with extracellular matrix abnormalities present even before clinical aortic stenosis develops.
OBJECTIVES: Calcific aortic valve disease (CAVD) is a progressive disease ranging from aortic valve (AoV) sclerosis to AoV stenosis (AS), characterised by severe calcification with impaired leaflet function. Due to the lack of early symptoms, the pathological progression towards valve dysfunction is poorly understood. The early patterns of AoV calcification and altered extracellular matrix (ECM) organisation were analysed in individuals postmortem without clinical AS compared with clinical AS. METHODS: Histological patterns of calcification and ECM organisation in postmortem AoV leaflets without clinical AS obtained from a tissue repository and surgical specimens obtained from individuals with clinical AS were compared with in vivo imaging prior to transcatheter AoV implantation. RESULTS: AoV calcification was detected in all samples from individuals >50 years old, with severity increasing with age, independent of known CAVD risk factors. Two distinct types of calcification were identified: 'Intrinsic', primarily found at the leaflet hinge of postmortem leaflets, accompanied by abnormal collagen and proteoglycan deposition; and 'Nodular', extending from the middle to the tip regions in more severely affected postmortem leaflets and surgical specimens, associated with increased elastin fragmentation and loss of elastin integrity. Even in the absence of increased thickening, abnormalities in ECM composition were observed in postmortem leaflets without clinical AS and worsen in clinical AS. CONCLUSIONS: Two distinct phenotypes of AoV calcification are apparent. While the 'nodular' form is recognised on in vivo imaging and is present with CAVD and valve dysfunction, it is unclear if the 'intrinsic' form is pathological or detected on in vivo imaging.
Gomez‐Stallons et al. (Wed,) conducted a observational in Calcific aortic valve disease. Histological analysis of postmortem aortic valves without clinical AS vs. Surgical specimens with clinical AS was evaluated on Histological patterns of calcification and extracellular matrix organisation. Histological analysis of human aortic valves identified two distinct calcification phenotypes ('intrinsic' and 'nodular'), with calcification present in all samples from individuals >50 years old.