Sex-mismatch influence on survival after heart transplantation: A systematic review and meta-analysis of observational studies

Introduction and objectives: Heart transplantation (HT) is the treatment for patients with end-stage heart disease. Despite contradictory reports, survival seems to be worse when donor/recipient sex is mismatched. This systematic review and meta-analysis aims to synthesize the evidence on the effect of donor/recipient sex mismatch after HT. Methods: We searched PubMed and EMBASE until November 2017. Comparative cohort and registry studies were included. Published articles were systematically selected and, when possible, pooled in a meta-analysis. The primary endpoint was one-year mortality. Results: After retrieving 556 articles, ten studies (76 175 patients) were included in the quantitative meta-analysis. Significant differences were found in one-year survival between sex-matched and mismatched recipients (odds ratio (OR) 1.30, 95% confidence interval (CI) 1.25-1.35, P <.001). In female recipients, we found that sex mismatch was not a risk factor for one-year mortality (OR = 0.93, 95% CI = 0.85-1.00, P =.06). However, in male recipients, we found that it was a risk factor for one-year mortality (OR = 1.38, 95% CI = 1.31-1.44, P <.001). Conclusions: Sex mismatch increases one-year mortality after HT in male recipients. Its influence in long-term survival should be further explored with high-quality studies.