Peri-operative risk factors of acute kidney injury after heart transplantation and one-year clinical outcomes: A retrospective cohort study

Objectives This study aims to identify perioperative risk factors of acute kidney injury after heart transplantation and to evaluate one-year clinical outcomes. Design A retrospective single-center cohort study. Setting At a university hospital. Participants All patients who underwent heart transplantation from January 2015 to December 2020. Interventions None. Measurements and Main Results We recorded acute kidney injury after heart transplantation. One-year mortality and renal function were also recorded. Risk factors of acute kidney injury were evaluated using a multivariable logistic regression model. Long-term survival was compared between patients developing acute kidney injury and those that did not using a log-rank test. Among 209 patients included in our study, 134 (64% [95% CI (58; 71) %]) developed post-transplantation acute kidney injury. Factors independently associated with acute kidney injury were high body mass index (OR: 1.18 [1.02-1.38] per kg/m2; p=0.030), prolonged duration of cold ischemic period (OR: 1.11 [1.01-1.24] per 10 min; p= 0.039) and high dose of intraoperative dobutamine support (OR: 1.24 [1.06-1.46] per µg/kg/min; p= 0.008). At one year, patients who developed postoperative acute kidney injury had higher mortality rates (20% vs 8%, p=0.015). Among 172 survivors at one year, 82 (48%) had worsened their renal function compared to pre- heart transplantation. Conclusions Our study highlights the high incidence of acute kidney injury after heart transplantation and its impact on patient outcomes. Risk factors such as body mass index, prolonged cold ischemic period duration and level of inotropic support with dobutamine were identified, providing insights for preventive strategies.