# Recipient Pericardial Apolipoprotein Levels Might Be an Indicator of Worse Outcomes after Orthotopic Heart Transplantation

## TL;DR

This study suggests that certain apolipoprotein levels in heart transplant recipients' pericardial fluid may predict worse outcomes, including rejection and mortality.

## Contribution

The study introduces apolipoprotein levels in pericardial fluid as potential biomarkers for predicting post-transplant complications.

## Key findings

- Higher ApoCII and ApoCIII levels in pericardial fluid were associated with increased mortality after heart transplantation.
- Elevated adiponectin, ApoCII, and ApoCIII levels were found in patients who experienced rejection after transplantation.
- Lower thyroxine levels in pericardial fluid were observed in patients who developed rejection.

## Abstract

Background: End-stage heart failure (ESHF) leads to hypoperfusion and edema formation throughout the body and is accompanied by neurohormonal and immunological alterations. Orthotopic heart transplantation (HTX) has been used as a beneficial option for ESHF. Due to the shortage of donor hearts, the ideal matching and timing of donors and recipients has become more important. Purpose: In this study, our aim was to explore the relationship between the clinical outcomes of HTX and the cytokine and apolipoprotein profiles of the recipient pericardial fluid obtained at heart transplantation after opening the pericardial sac. Materials and methods: The clinical data and the interleukin, adipokine, and lipoprotein levels in the pericardial fluid of twenty HTX recipients were investigated. Outcome variables included primer graft dysfunction (PGD), the need for post-transplantation mechanical cardiac support (MCS), International Society for Heart and Lung Transplantation grade ≥2R rejection, and mortality. Recipient risk scores were also investigated. Results: Leptin levels were significantly lower in patients with PGD than in those without PGD (median: 6.36 (IQR: 5.55–6.62) versus 7.54 (IQR = 6.71–10.44); p = 0.029). Higher ApoCII levels (median: 14.91 (IQR: 11.55–21.30) versus 10.31 (IQR = 10.02–13.07); p = 0.042) and ApoCIII levels (median: 60.32 (IQR: 43.00–81.66) versus 22.84 (IQR = 15.84–33.39); p = 0.005) were found in patients (n = 5) who died in the first 5 years after HTX. In patients who exhibited rejection (n = 4) in the first month after transplantation, the levels of adiponectin (median: 74.48 (IQR: 35.51–131.70) versus 29.96 (IQR: 19.86–42.28); p = 0.039), ApoCII (median: 20.11 (IQR: 13.06–23.54) versus 10.32 (IQR: 10.02–12.84); p = 0.007), and ApoCIII (median: 70.97 (IQR: 34.72–82.22) versus 26.33 (IQR: 17.18–40.17); p = 0.029) were higher than in the nonrejection group. Moreover, the pericardial thyroxine (T4) levels (median: 3.96 (IQR: 3.49–4.46) versus 4.69 (IQR: 4.23–5.77); p = 0.022) were lower in patients with rejection than in patients who did not develop rejection. Conclusion: Our results indicate that apolipoproteins can facilitate the monitoring of rejection and could be a useful tool in the forecasting of early and late complications.