Effects of Butanedione Monoxime and Temperature on Prolonged Cardiac Storage

Background. The optimal temperature for cardiac allograft storage remains controversial. We conjectured that supplementation of the potent cardioprotective agent 2,3-butanedione monoxime with calcium may improve allograft storage and make the precise storage temperature less critical. Methods. Hearts were harvested from Sprague-Dawley rats (250 to 350 g), mounted on a Langendorff apparatus, and instrumented with an intraventricular balloon. Hearts were flushed and stored with either unmodified University of Wisconsin solution (UWS) or UWS supplemented with 10 mmol/L of 2,3-butanedione monoxime and calcium 0.1 mmol/L (BDM). Hearts were then subjected to 12 hours of storage at one of five temperatures (0°, 4°, 8°, 12°, or 16°C) in a complete 2 × 5 factorial design (n = 6/group). Data are reported either as a percentage of the prestorage results or as an absolute value (mean ± standard deviation). Results. Recovery of developed pressure (p < 0.0001), coronary flow (p < 0.0001), and diastolic volume (p < 0.001) were significantly enhanced, whereas creatine kinase (p < 0.0001) and lactate dehydrogenase release (p < 0.0001) were reduced in the BDM versus the UWS groups. In both the BDM and UWS storage groups, recovery was better at temperatures of 8°C or less than at 12°C or more. The single preferred temperature was 4°C, significantly better than 0°C with unmodified UWS, while similar to 0° and 8°C with BDM. Adenine nucleotide values were decreased equally in the BDM and UWS hearts, but preservation was enhanced at 0°C compared with all warmer temperatures. Conclusions. We conclude that 4°C is the preferred temperature for prolonged cardiac storage with UWS and that the inclusion of 2,3-butanedione monoxime with calcium 0.1 mmol/L markedly enhances recovery for storage temperatures of 8°C or less. (Ann Thorac Surg 1997;63:388–94)