Relationship of Laser-Doppler-Flow and coronary perfusion and a concise update on the importance of coronary microcirculation in donor heart machine perfusion

Issue title: 40th Conference of the German Society for Clinical Microcirculation and Hemorheology, 5-6 November 2021, Senftenberg, Germany

Guest editors: J.-H. Küpper, A. Krüger-Genge and F. Jung

Article type: Research Article

Authors: Saemann, Lars^{a; b; *} | Großkopf, Anne^a | Hoorn, Fabio^{b; c} | Veres, Gábor^a | Guo, Yuxing^a | Korkmaz-Icöz, Sevil^b | Karck, Matthias^b | Simm, Andreas^a | Wenzel, Folker^c | Szabó, Gábor^{a; b}

Affiliations: [a] Department of Cardiac Surgery, University Hospital Halle (Saale), Halle (Saale), Germany | [b] Department of Cardiac Surgery, Heidelberg University Hospital, Heidelberg, Germany | [c] Faculty Medical and Life Sciences, Furtwangen University, Villingen-Schwenningen, Germany

Correspondence: [*] Corresponding author: Lars Saemann, Ernst-Grube-Straße 40, 06120 Halle, Germany. Tel.: +49 15785852859; E-mail: lars.saemann@uk-halle.de; ORCID ID: https://orcid.org/0000-0003-1516-3286.

Abstract: BACKGROUND:Machine perfusion (MP) is a novel method for donor heart preservation. The coronary microvascular function is important for the transplantation outcome. However, current research on MP in heart transplantation focuses mainly on contractile function. OBJECTIVE:We aim to present the application of Laser-Doppler-Flowmetry to investigate coronary microvascular function during MP. Furthermore, we will discuss the importance of microcirculation monitoring for perfusion-associated studies in HTx research. METHODS:Porcine hearts were cardioplegically arrested and harvested (Control group, N = 4). In an ischemia group (N = 5), we induced global ischemia of the animal by the termination of mechanical ventilation before harvesting. All hearts were mounted on an MP system for blood perfusion. After 90 minutes, we evaluated the effect of coronary perfusion pressures from 20 to 100 mmHg while coronary laser-doppler-flow (LDF) was measured. RESULTS:Ischemic hearts showed a significantly decreased relative LDF compared to control hearts (1.07±0.06 vs. 1.47±0.15; p = 0.034). In the control group, the coronary flow was significantly lower at 100 mmHg of perfusion pressure than in the ischemia group (895±66 ml vs. 1112±32 ml; p = 0.016). CONCLUSIONS:Laser-Doppler-Flowmetry is able to reveal coronary microvascular dysfunction during machine perfusion of hearts and is therefore of substantial interest for perfusion-associated research in heart transplantation.

Keywords: Heart transplantation, myocardial microcirculation, coronary microvasculature, machine perfusion, microvascular dysfunction

DOI: 10.3233/CH-219116

Journal: Clinical Hemorheology and Microcirculation, vol. 79, no. 1, pp. 121-128, 2021