Electrical graft assessment of machine-perfused hearts donated after circulatory death.

Abstract

Background: Normothermic ex situ heart perfusion (ESHP) has increased the donor pool with hearts donated after circulatory death (DCD), but functional assessment during ESHP using lactate trends is suboptimal. This study presents the clinical use of high-resolution cardiac mapping to assess electrical function of human DCD hearts on ESHP, where low-voltage-areas might be indicative of myocardial injury.

Methods: Hearts were procured following circulatory arrest of the donor and restarted on normothermic ESHP. DCD hearts were transported to the recipient hospital and lactate concentrations were regularly measured in the perfusate. High-resolution epicardial mapping of the left (LV) and right ventricle (RV) was performed with a 192-electrode array during normothermic ESHP prior to transplantation. Unipolar potential voltages and slopes, conduction velocity and the amount of low-voltage potentials and conduction block were calculated from these recordings.

Results: Electrical mapping was performed on ten DCD hearts transported on ESHP with sequential cardiac transplantation, showing safety and feasibility of the technique. Median potential voltage of the LV and RV was 15.7 mV (14.0-17.4 mV) and 11.3 mV (8.3-11.9 mV) respectively, and low-voltage potentials were minimally present. In comparison, the electrical function of one rejected heart with increasing lactate trend did not differ from the transplanted hearts.

Conclusions: High-resolution electrical mapping of DCD hearts on ESHP may serve as novel additional diagnostic tool for assessing graft function, especially in marginal donors.