Evaluation of the Added Clinical Value of Donor-derived Cell-free DNA for the Monitoring of Cardiac Allograft Rejection: an Observational Prospective Longitudinal Multicenter Study.

Despite major advances in immunosuppression, allograft rejection remains an important complication after heart transplantation. International guidelines recommend performing routine endomyocardial biopsies (EMB) to detect allograft rejection with the goal of identifying rejection at a subclinical state. However, this invasive strategy suffers from major limitations, making an improvement in individual risk stratification of rejection highly needed. Major advances in the field of non-invasive biomarkers of cardiac rejection have been made. Strong associations between donor-derived cell-free DNA (dd-cfDNA) and cardiac rejection have been reported, including in properly designed prospective observational studies with a longitudinal follow-up. However, the independent nature of this association and the improvement in individual risk stratification with dd-cfDNA on top of routine parameters have not yet been demonstrated. The aim of our study is to challenge, in a large observational prospective cohort, the clinical added value of dd-cfDNA with a previously published robust rejection predictive model including the following variables: time post-transplant, pre-transplant sensitizing event, circulating anti-HLA donor-specific antibodies (DSA) with mean fluorescence intensity ≥ 3,000, acute graft dysfunction and prior history of rejection.