Purpose: To evaluate the association between donors\u2019 and recipients\u2019 serum levels of soluble ST2 (sST2) and recipients\u2019 primary graft dysfunction and 1-year outcome (mortality and incidence of allograft rejection). Methods: Consenting recipients and donors were prospectively enrolled in the study. Clinical records of donors as well as the absence of opposition to samples collection for scientific purposes were provided by the Agence de la Biomedicine, the French Agency for organ transplantation. Blood samples were collected in heart donors before organ procurement and in recipients before heart transplantation, at postoperative day (pod) 7 and at the time of each endomyocardial biopsy during the first year after transplantation. Serum levels of sST2 was evaluated by ELISA. Results: From February 2016 to October 2016, 50 donors and 50 recipients were enrolled in the study. Donors aged > 50 years, with hystory of cardiac arrest, with LVEF < 60% and with inotropic support (norepinephrine > 2mg/mL) had significantly higher serum levels of sST2 [196 vs 141 ng/mL (p=0.03), 210 vs 154 ng/mL (p= 0.03), 205 vs 157 ng/mL (p= 0.03) and 207 vs 158 ng/mL (p =0.04) respectively]. Recipients who were transplanted while on national high emergency waiting list had significantly higher preoperative serum levels of sST2 (61 vs 41 ng/mL; p= 0.003). No difference was observed in recipients\u2019 preoperative serum levels of sST2 with regards to age, type of cardiomyopathy, presence of preoperative ecmo, hyperimmunisation requiring plasmapheresis. Recipients who needed a postoperative ecmo for primary graft dysfunction had significantly higher serum levels of sST2 in their corresponding donors (203 vs 122 ng/mL; p = 0.007). Recipients with ischemic time > 180 min and recipients who developed a postoperative sepsis had significantly higher serum levels of sST2 at pod7 (160 vs 114 ng/mL (p= 0.02 and 238 vs 136 ng/mL (p= 0.03) respectively). Recipients who died during the first year after transplantation had significantly higher serum levels of sST2 at pod7 compared to recipients who did not (256 vs 141 ng/mL; p= 0.008). No difference was observed in sST2 serum levels in recipients who had allograft rejection during the first year after transplantation and recipient who did not. Conclusion: Higher sST2 serum levels in donors are associated with primary graft dysfunction in recipients; higher sST2 serum levels in recipients at pod7 are associated with 1-year mortality
