Development of a Prediction Model for Donor Heart Function Based on Myocardial Microcirculation during Ex Vivo Blood Perfusion

Objectives: Ex vivo blood perfusion (EVBP) is a new method for the maintenance of donor hearts. Nevertheless, contractile function of the donor heart cannot be evaluated during EVBP. Lactate concentration (Lac) as a metabolic surrogate marker is the only parameter to indirectly reflect donor heart viability and to predict transplantation outcome to a certain extent. Thus, we developed a prediction model for donor heart function based on monitoring of myocardial microcirculation.

Methods: After explantation, eight pig hearts underwent EVBP for 4 hours, followed by a functional evaluation period. During 4 hours of EVBP, Lac was measured every 30 minutes and myocardial microcirculation (mLDP) was measured by laser Doppler perfusion monitoring. Various novel course parameters based on mLDP were computed. Hemodynamic parameters were measured with a left ventricular balloon catheter. Lac and mLDP were undertaken; correlation and regression analyses with Box-Cox transformed contractile parameters.

Result: In a single-variable regression analysis, Lac did not show significant R ². Instead, mLDP was superior for prediction of systolic (R ² = 0.514; p = 0.045) and diastolic (R ² = 0.501; p = 0.0496) parameters. In a two-variable regression analysis, the combination of two mLDP-based parameters showed best prediction of ESP (R ² = 0.776; p = 0.024) and EDP (R ² = 0.883; 0.005). dp/dtmax was predicted best by a combination of mLDP and Lac (R ² = 0.876, p = 0.005).

Conclusion: In a single-variable model, mLDP is superior to Lac to predict systolic as well as diastolic donor heart function in an ex vivo–evaluated donor heart. In a two-variable model, the combination of either two mLDP-based parameters or of mLDP combined with Lac serve best to predict systolic and diastolic function. Two-variable prediction models are superior to one-variable models.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
19 February 2021