Improved cardiac preservation by the addition of nitroglycerine to colloid-free University of Wisconsin solution (MUW)

Background: This study examines whether the addition of nitroglycerine, a known coronary vasodilator and nitric oxide donor, to colloid-free University of Wisconsin solution will improve and extend cardiac preservation. Methods: Rat hearts were flushed and stored in colloid-free University of Wisconsin solution with or without the addition of nitroglycerine for 12, 16 or 20 hours at 0 degrees C before heterotopic transplantation with an indwelling externalized intraventricular balloon-tipped catheter. One and 7 days after transplantation of the heart the catheter was connected to a pressure transducer and quantitative functional studies were performed. Results: After 12 hours preservation with nitroglycerine in colloid-free University of Wisconsin solution 6/6 grafts continued to beat for 7 days compared to 3/6 without nitroglycerine. After 16 hours preservation the addition of nitroglycerine 5/7 hearts continued to beat for 7 days compared to 0/6 without nitroglycerine (p < .05). Only 1/6 hearts beat for 7 days after 20 hours preservation with nitroglycerine. On Days 1 and 7, the left ventricular developed pressure (LVDP), contractility (max dP/dt) and rate of relaxation (peak -dP/dt) of 12 hour preserved hearts was better (p < .05) when nitroglycerine was present. The function of hearts preserved with the addition of nitroglycerine was similar after 12 and 16 hours preservation. Conclusion: Nitroglycerine is a valuable additive to colloid-free University of Wisconsin solution, extending effective preservation of the rat heart to 16 hours and significantly improving left ventricular function after 12 and 16 hours preservation. The addition of nitroglycerine, however, did not extend preservation to 20 hours.