Sex-mismatch influence on survival after heart transplantation: A systematic review and meta-analysis of observational studies.Ayesta, A., Urrútia, G. et al. (2019).
Clinical Transplantation; 33(12): e13737.
This systematic review and meta-analysis aims to synthesize the evidence on the effect of donor/recipient sex mismatch after heart transplantation (HT).
The PubMed and EMBASE database was searched until November 2017 for comparitive cohort and registry studies.
Ten studies (n=76175 heart transplant patients) were included in the quantitative meta-analysis.
Primary outcome being assessed was one-year mortality, following heart transplantation.
This is a well written report of a well conducted systematic review. Pubmed and EMBASE were searched for papers and they were filtered in duplicate. Three reviewers extracted data but it is unclear if this was done in triplicate or in parallel. A large number of transplants were included (76,175) represented in 10 papers and the authors took steps to prevent duplication of results. Despite one study dominating the results due to its very large size (the ISHLT registry) all of the other studies favoured no mismatch in donor and recipient sex, even if not statistically significantly. Heterogeneity as assessed by I-squared statistic was 0%. Overall the meta-analysis showed a 30% increase in survival when donor and recipient sex were matched. When separating male and female recipients, male recipients did significantly worse if receiving a female donor heart, whilst for female recipients the donor sex was not statistically significant (p=0.06). It has been speculated that differences in predicted cardiac mass are to blame, although some analyses have not supported this. The reasons for the interaction between sex mismatch and early survival are not clear.