Calcification of Bioprosthetic Heart Valves Biochemical substrate and prevention

Calcification of the leaflets of bioprosthetic heart valves (BHV) made from glutaraldehyde treated bovine or porcine pericardium or porcine aortic valves is related to the failure of these devices. The aim of this study is to evaluate the degeneration and calcification of explanted BHV and to analyze the underlying chemical substrate and risk factors. The authors performed a retrospective study on 47 cases with dysfunctional aortic BHV that were explanted and replaced between January 2000-November 2014. Hospital records, laboratory test results, cardiac computed tomography angiography (cardiac CTA) results, and operative data were reviewed and statistically analyzed. Mean valve survival time was of 11.5 ± 4.2 years. Coronary CTA revealed the presence of BHV calcifications in 38 out of the 47 cases (25 patients presented only punctate calcifications, 11 cases presented moderate cuspal calcifications and 2 cases presented gross calcifications associated to cuspal thickening and deformation). Glutaraldehyde fixation process of BHV may lead to degeneration and calcification of this type of valves, and in our opinion, the most promising preventive strategies have to include binding of calcification inhibitors to glutaraldehyde fixed tissue, removal or modification of calcifiable components, modification of glutaraldehyde fixation, and use of tissue cross linking agents other than glutaraldehyde.