Beta-adrenergic receptor polymorphisms and cardiac graft function in potential organ donors

Area of Science:

• Cardiovascular Genetics
• Transplantation Immunology
• Organ Donor Management

Background:

• Left ventricular dysfunction is a significant barrier to heart allograft utilization.
• Beta-adrenergic receptor (βAR) polymorphisms have been previously linked to cardiac dysfunction.

Purpose of the Study:

• To investigate the association between βAR single nucleotide polymorphisms (SNPs) and the predisposition of donor hearts to left ventricular (LV) dysfunction following brain death.
• To explore the impact of specific βAR SNPs on cardiac function and management requirements in organ donors.

Main Methods:

• Genotyping of four βAR SNPs (β1AR 1165C/G, β1AR 145A/G, β2AR 46G/A, β2AR 79C/G) in 1043 organ donors managed between 2001-2006.
• Multivariable regression analyses to assess the association between βAR SNPs and LV systolic dysfunction (defined by ejection fraction <50%) and dopamine requirements.
• A validation cohort of 364 donors managed from 2007-2008 was used to confirm findings.

Main Results:

• The β2AR 46 SNP was significantly associated with LV systolic dysfunction; each minor allele decreased the odds of LV ejection fraction <50%.
• The β1AR 1165 and β2AR 46 SNPs were linked to a higher requirement for dopamine during donor management.
• No significant associations were found in the validation cohort, potentially due to changes in donor management or reduced statistical power.

Conclusions:

• βAR polymorphisms may play a role in cardiac dysfunction after brain death, impacting organ donor suitability.
• Further research in independent donor cohorts is necessary to validate these findings and elucidate the precise mechanisms.
• Understanding these genetic associations could potentially improve donor selection and management strategies in transplantation.