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.