Table 1.

Six main differences between native and bioprosthetic heart valves

Parameter	Explanation	Ref.
Passive calcification mechanism	Both native and bioprosthetic heart valves involve passive calcification mechanisms. However, bioprosthetic valves, the effect of the debris of untreated dead cells is more pronounced.	[24]
The effect of the crosslinking agent “glutaraldehyde”	The presence of glutaraldehyde in bioprosthetic valves showed some procalcifying events: -Deactivation of membranes pumps allowing Ca2+ leakage from the mitochondrial membranes. -Increasing exposed areas through formation of void spaces. -Non-neutralized residues of glutaraldehyde. -Exposing larger numbers of more negative charges due to crosslinking of basic amino acids.	[27]
Bioprosthetic heart valve is accelerated version of native calcification	The calcification of native heart valves is a slowly proceeding disease. However, the bioprosthetic heart valves show a faster rate of progression in both children and elders.	[21]
Age prevalence of incidence	For non-pathological conditions, elders are under high risk of calcification of heart valves in comparison to children. In contrast, with bioprosthetic heart valves substitutes, the children would develop much faster calcification.	[28, 29]
Structural differences of calcific deposits	The solubility of mineral deposits of bioprosthetic heart valves is higher than in the corresponding deposits in the native valves.	[32]
Immunological consideration	Several immune responses have been involved in calcification of native heart valves. However, there is no sufficient evidences to support their role in calcification of bioprosthetic heart valves.	[21]