Related Experiment Videos
Glutaraldehyde, gamma-carboxyglutamic acid and calcium in explanted bioprosthetic heart valves
H Hughes1, L S Tipton, D Feuchuk
1Biological and Medical Research Department, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
Insights
Bioprosthetic heart valves show decreased glutaraldehyde over time, but no link between gamma-carboxylglutamic acid (gamma-CGA) and calcification. Gamma-CGA appears absorbed, not causative, in valve explants.
Area of Science:
- Biomaterials Science
- Cardiovascular Research
- Biochemistry
Background:
- Bioprosthetic heart valves (BHVs) are susceptible to calcification, a major cause of failure.
- Understanding the degradation and calcification mechanisms of BHVs is crucial for improving their longevity.
- Glutaraldehyde fixation and gamma-carboxylglutamic acid (gamma-CGA) are key factors in BHV tissue processing and biological interactions.
Purpose of the Study:
- To quantify glutaraldehyde, gamma-CGA, and calcium levels in explanted bioprosthetic heart valves.
- To investigate the relationship between these components and the duration of implantation.
- To elucidate the role of gamma-CGA in the calcification process of BHVs.
Main Methods:
- Analysis of nine explanted bioprosthetic heart valves.
- Quantification of glutaraldehyde and gamma-CGA using high-performance liquid chromatography (HPLC).
- Determination of calcium concentration via atomic absorption spectrometry.
Main Results:
- Glutaraldehyde was detected in only two valves at significantly reduced levels (17% and 2%) compared to unimplanted valves.
- No correlation was found between gamma-CGA and calcium deposition in the explanted valves.
- Acid-hydrolyzable glutaraldehyde decreased over time, but this decrease did not correlate with implantation duration.
Conclusions:
- Glutaraldehyde levels decrease in bioprosthetic heart valves after implantation.
- Gamma-CGA is likely absorbed from circulation onto calcium deposits, rather than contributing to calcification.
- The degradation of glutaraldehyde is time-dependent but not directly correlated with implantation duration.
Abstract:
This paper describes the determination of glutaraldehyde, gamma-carboxylglutamic acid (gamma-CGA) and calcium concentrations in nine bioprosthetic heart valves after explantation. The glutaraldehyde and gamma-CGA were determined by high performance liquid chromatography (HPLC) procedures and the calcium by atomic absorption spectrometry. Glutaraldehyde was detectable in only two of these valves at levels of 17% and 2% of that present in an unimplanted valve. The results indicate that there is no correlation between gamma-CGA and calcium deposition, indicating that the gamma-CGA is probably absorbed onto the forming calcium deposit from the circulation and does not contribute to the calcification process, and that the acid hydrolysable glutaraldehyde decreases with time during implantation. There is, however, no correlation between the duration of implantation and the decrease in glutaraldehyde concentration.