# Prediction of Kidney Function Improvement After Heart Transplantation

## TL;DR

This study identifies factors that predict improved kidney function after heart transplantation in patients with advanced heart failure.

## Contribution

The study introduces new predictors of kidney function improvement after heart transplantation, including preoperative bilirubin levels and the absence of postoperative renal replacement therapy.

## Key findings

- Higher preoperative total bilirubin levels are independently associated with improved kidney function after heart transplantation.
- Patients who did not require renal replacement therapy early after surgery were more likely to experience kidney function improvement.
- Improvement in kidney function after heart transplantation is uncommon and occurs in specific patient subgroups.

## Abstract

Background/Objectives: Patients with advanced heart failure (HF) often suffer from impaired kidney function. Based on the pathophysiology of types I and II of cardiorenal syndrome, heart transplantation (Htx) may restore renal function. The aim of this study was to identify predictors of improvement in kidney function after HTx. Methods: Htx patients from a tertiary hospital were retrospectively divided into three groups—improvement (n = 24), deterioration (n = 31) and no significant change in eGFR (n = 45)—based on changes in their mean estimated glomerular filtration rate (eGFR) within the first three postoperative months, compared to the last three preoperative months. The threshold for eGFR improvement was defined as a ≥20% increase, while deterioration was defined as a ≥20% decrease. The no significant change group was defined as any change falling between these two values. Results: The median age of analyzed cohort was 54 (45–63) years, and 82% were male. Preoperatively, the improvement group was more frequently treated with inotropes or vasopressors and had significantly higher blood urea and total bilirubin levels before Htx. In the multivariate analysis, total bilirubin before Htx (OR 1.66; 95% CI; 1.24–2.69; p = 0.002) and no need for RRT early after Htx (OR 0.46; 95% CI 0.24–0.88; p = 0.02) were independent predictors of improved kidney function in the first three months after HTx. Conclusions: The improvement in renal function after HTx is uncommon. It could be expected in patients suffering from more severe forms of HF, with impaired kidney and liver function but who did not need RRT after the surgery.