Introduction: Limited research has explored heart transplantation (HT) outcomes in patients with sex-mismatched organ donors and recipients. Findings on which type of sex-mismatch has worse post-transplant outcomes have been contradictory.
Methods: We searched Medline, Embase, Scopus and Cochrane for publications reporting HT outcomes according to donor/recipient sex mismatch through May 2017. Sex mismatched HT male recipients were compared to non-mismatched male recipients, and sex mismatched HT female recipients were compared to non-mismatched female recipients. Outcomes were compared under the random-effects model and heterogeneity examined via Chi2 and I2 statistics. Sensitivity analyses were performed.
Results: A total of 8 studies including 110211 patients were included in the analysis. Of these, 80% were male recipients and 29% had sex-mismatched transplants. In male recipients, sex mismatch was associated with a higher rate of rejection (OR 1.25; 95% CI 1.19-1.32; p<0.00001). In female recipients, sex mismatch was associated with less rejection (OR 0.72; 95% CI 0.53-0.97; p=0.03). Sex mismatch was not associated with early mortality in either sex. Mortality at 10 years had a tendency of being greater in both male and female mismatched patients; however, the heterogeneity was high and it did not achieve statistical significance (Figure 1).
Conclusions: Our analysis suggests that sex-mismatch in HT may affect the incidence of rejection without necessarily having clear impact on mortality. Sex-mismatch in HT remains an area in need of investigation and further studies are needed to determine if sex-mismatch truly influences HT outcomes.