# Cardioplegic Machine Perfusion of Hearts Donated after Circulatory Death

## TL;DR

This study shows that machine perfusion with HTK-N improves heart function and microcirculation in donor hearts compared to Del Nido cardioplegia.

## Contribution

The study introduces a novel comparison of HTK-N and Del Nido cardioplegia in machine perfusion for DCD hearts.

## Key findings

- HTK-N perfusion resulted in significantly better left-ventricular contractility than Del Nido cardioplegia.
- Microcirculation was improved with HTK-N as shown by higher Laser-Doppler-Flow measurements.
- HTK-N upregulated longevity pathways and downregulated aging pathways compared to Del Nido cardioplegia.

## Abstract

We compared the effects of ex-vivo machine perfusion (EVMP) of hearts donated after circulatory death (DCD) with the single-shot solutions HTK-N and Del Nido cardioplegia (DNC) on left-ventricular (LV) contractility and myocardial microcirculation. In a DCD pig model, hearts were maintained by EVMP with hypothermic, oxygenated HTK-N (DCD-HTK-N; N = 8) or DNC (DCD-DNC; N = 8) followed by reperfusion with blood, including assessment of contractility and microcirculation with Laser-Doppler-Flow (LDF). We performed transcriptomics using microarrays. In DCD-HTK-N, the ESP, dp/dtmax and dp/dtmin were significantly higher (p < 0.05) compared to DCD-DNC. Relative LDF was higher in DCD-HTK-N vs. DCD-DNC. Pathways related to inflammatory mediators, cAMP, ion channels, intracellular signaling, and cell death were regulated differently. In DCD-HTK-N, longevity-associated pathways were up-, and ageing-associated pathways were downregulated. EVMP of DCD hearts with HTK-N results in a superior LV function, microcirculation, and regulation of pathways with short- and long-term relevance compared to DNC.