Donor heart preservation with a novel hyperpolarizing solution: Superior protection compared with University of Wisconsin solution

Objectives: A donor heart preservation solution was designed to use hyperpo larized arrest with the adenosine triphosphate-sensitive potassium-channel opener pinacidil. This solution contained concentrations of potassium, sodi um, calcium, magnesium, lactobionate, and the buffer histidine specifically chosen to minimize intracellular calcium accumulation associated with prol onged ischemia. Methods: Twenty-four rabbit hearts were randomly assigned to receive 1 of 3 preservation solutions in a crystalloid-perfused Langendorff model: (1) pr ototype solution containing a 0.5 mmol/L concentration of pinacidil, (2) pr ototype solution without pinacidil as control, and (3) University of Wiscon sin solution. Thirty minutes of initial perfusion preceded baseline data ac quisition. Data comprised left ventricle pressure-volume curves generated b y inflating an intraventricular latex balloon. After cardioplegic administr ation, hearts underwent 4 hours of hypothermic storage, followed by 60 minu tes of reperfusion and postischemic data acquisition. Results: Postischemic developed pressure was better preserved by pinacidil solution (92.4% +/- 4.5%) than by the control (74.9% +/- 3.4%, P =.01) and University of Wisconsin solutions (66.7% +/- 5.1%, P =.001). Diastolic nega tive dP/dT was better preserved by pinacidil solution (104.4% +/- 10.2%) th an by the control (80.2% +/- 4.2%, P =.034) and University of Wisconsin sol utions (71.7% +/- 7.0%, P =.015). Diastolic compliance, expressed as baseli ne/postischemic diastolic slope ratios, was more poorly preserved by Univer sity of Wisconsin solution (0.67 +/- 0.07) than by the pinacidil (0.88 +/- 0.05, P =.041) and control solutions (0.87 =/- 0.05, P =.021). Postischemic coronary Row was higher in hearts exposed to pinacidil solution (77.8% +/- 3.0%) than in those exposed to the control (66.8% +/- 2.4%) and University of Wisconsin solutions (70.9% +/- 4.0%, P =.07). Conclusions: The superiority of the pinacidil solution in this experiment d emonstrated that hyperpolarized arrest with potassium-channel openers impro ves donor heart preservation when administered in a novel histidine-buffere d lactobionate-enriched vehicle.