Risk Factors for Acute Kidney Injury Requiring Renal Replacement Therapy after Orthotopic Heart Transplantation in Patients with Preserved Renal Function

Background: Acute kidney injury (AKI) requiring renal replacement therapy (RRT) is a serious complication after orthotopic heart transplantation (HTX). In patients with preexisting impaired renal function, postoperative AKI is not surprising. However, even in patients with preserved renal function, AKI requiring RRT is frequent. Therefore, this study aimed to identify risk factors associated with postoperative AKI requiring RRT after HTX in this sub-cohort.

Method: This retrospective cohort study included patients ≥18 years who underwent HTX at the University Hospital Duesseldorf, Germany, from 2010 to 2021. Preserved renal function was defined as preoperative creatinine-based glomerular filtration rate ≥60 mL/min. The association between all available patient- and procedure-related factors with postoperative AKI requiring RRT within 72 hours after HTX was assessed in univariate logistic regression models. Based on systematic literature research, most suitable significant variables were included into multivariate logistic regression.

Results: A total of 206 patients were screened for this study. Thirteen patients had hemodialysis prior to HTX and 86 patients had baseline GFR < 60 mL/min. Based on the inclusion and exclusion criteria, 107 patients remained for statistical analysis (mean age: 52 ± 12 years, 78.5% male, 45.8% AKI requiring RRT). After univariate analysis, use of extracorporeal membrane oxygenation, postoperative infection, levosimendan therapy, duration of norepinephrine (NE) therapy, and maximum daily increase in tacrolimus plasma levels were included into multivariate analysis. Duration of NE therapy and maximum daily increase in tacrolimus plasma levels remained as independent significant risk factors (NE: OR 1.01, 95% CI: 1.00–1.02, p = 0.005; increase in tacrolimus plasma level: OR 1.18, 95% CI: 1.01–1.37, p = 0.036). In addition, there was a nonsignificant trend for VA-ECMO due to primary graft dysfunction after HTX (OR: 4.54, 95% CI: 0.96–21.43; p = 0.056).

Conclusion: This retrospective cohort study identified prolonged NE therapy and maximum daily increase in tacrolimus plasma levels as risk factors for AKI requiring RRT in HTX patients with preserved renal function. These results are clinically relevant and new therapeutic approaches for HTX patients are urgently needed. In this context, the role of calcineurin inhibitor free induction therapy or extended release tacrolimus should be investigated.

Publication History

Article published online:
03 February 2022