Effect of recipient gender and donor-specific antibodies on antibody-mediated rejection after heart transplantation

Gender-difference regarding antibody-mediated rejection (AMR) after heart transplantation has been described. However, no study accounted for the presence of preformed donor-specific antibodies (pfDSA), a known risk factor of AMR, more common among women than men. In a single-institution 6-year cohort (2010-2015), time to AMR was assessed, comparing men with women by survival analysis with a 1-year death-censored follow-up. All AMRs were biopsy proven. Confounding variables that were accounted for included mean intensity fluorescence (MFI) of pfDSA, recipient age, HLA-, size- and sex-mismatch. 463 patients were included. Overall incidence of AMR was 10.3% at 1 year. After adjusting for confounding variables, independent risk factors of AMR were female recipient gender (adjusted hazard-ratio [adj. HR] = 1.78 [1.06-2.99]), P = .03) and the presence of pfDSA (adj. HR = 3.20 [1.80-5.70], P < .001). This association remained significant when considering pfDSA by their MFI; female recipient gender had an adj. HR = 2.2 (P = .026) and MFI of pfDSA (per 1 MFI-increase) adj. HR = 1.0002 (P < .0001). In this cohort, women were at higher risk of AMR than men and this risk increase was additive to that of pfDSA. These findings may suggest a gender-related difference in the severity of pfDSA.

Performance of existing risk scores around heart transplantation: validation study in a 4-year cohort

Several risk scores exist to help identify best candidate recipients for heart transplantation (HTx). This study describes the performance of five heart failure risk scores and two post-HTx mortality risk scores in a French single-centre cohort. All patients listed for HTx through a 4-year period were included. Waiting-list risk scores [Heart Failure Survival Score (HFSS), Seattle Heart Failure Model (SHFM), Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC), Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) and Get With The Guidelines-Heart Failure (GWTG-HF)] and post-HTx scores Index for Mortality Prediction After Cardiac Transplantation (IMPACT and CARRS) were computed. Main outcomes were 1-year mortality on waiting list and after HTx. Performance was assessed using receiver operator characteristic (ROC), calibration and goodness-of-fit analyses. The cohort included 414 patients. Waiting-list mortality was 14.0%, and post-HTx mortality was 16.3% at 1-year follow-up. Heart failure risk scores had adequate discrimination regarding waiting-list mortality (ROC AUC for HFSS = 0.68, SHFM = 0.74, OPTIMIZE-HF = 0.72, MAGGIC = 0.70 and GWTG = 0.77; all P-values <0.05). On the contrary, post-HTx risk scores did not discriminate post-HTx mortality (AUC for IMPACT = 0.58, and CARRS = 0.48, both P-values >0.50). Subgroup analysis on patients undergoing HTx after ventricular assistance device (VAD) implantation (i.e. bridge-to-transplantation) (n = 36) showed an IMPACT AUC = 0.72 (P < 0.001). In this single-centre cohort, existing heart failure risk scores were adequate to predict waiting-list mortality. Post-HTx mortality risk scores were not, except in the VAD subgroup.