20-year analysis of protocol-driven quality improvement in cardiac homograft banking

Cardiac homografts are indispensable in complex cardiac surgery, particularly in the paediatric population. Optimising procurement and minimising discard rates are important for maintaining graft availability, especially in resource-limited settings. This study evaluated 20 years of cardiac homograft procurement at a tertiary cardiovascular centre, focusing on discard rates, causes of discard, microbiological profiles, and the impact of protocol refinements. A retrospective analysis was conducted using procurement records from the Cardiac Homograft Tissue Bank at the Institut Jantung Negara, Malaysia, between January 2004 and December 2024. The data collected included annual procurement volume, reasons for discarding, and microbiological culture results. In 2015, a revised procurement protocol was introduced, which incorporated instrument and operative field segregation, aseptic redraping, and enhanced donor screening. A total of 190 hearts were procured (mean 9.05 ± 4.18 hearts/year), with an overall discard rate of 13.7% (of 26/190). Prior to 2015, the discard rate was 17.2% (20/116), with environmental contamination accounting for the majority of the discards (75%; n=15). Fifteen microbial isolates were identified in the pre-revision period: Candida (n=6), Klebsiella (n=4), Acinetobacter (n=2), Streptococcus spp. (n=1), Streptococcus viridans (n=1), and Pseudomonas spp. (n=1). Following the 2015 protocol revision, the overall discard rate decreased to 8.1% (6/74), representing a 53% reduction, although this difference was not statistically significant (p=0.074). Environmental contamination-related discards decreased significantly from 12.9% (15/116) to 1.4% (1/74) (89% reduction; p=0.005), with only one Candida isolate identified post-revision. Protocol refinement has therefore produced a statistically significant reduction in contamination-related discards and a shift in the microbiological spectrum.