Eighteen-hour preservation of rat hearts with hexanol and pyruvate cardioplegia

Department of Medicine, University of California San Francisco 94143-0124.

OBJECTIVES. The aim of this study was to evaluate the effectiveness of 1-hexanol as an arresting agent and pyruvate as a substrate in a cardioplegic solution. BACKGROUND. Heart transplantation is limited in part by the short preservation time of donor hearts. Better preservation techniques would improve patient survival and the time and geographic area for using donor hearts. We previously showed that a cardioplegic solution containing ethanol and pyruvate was superior to a conventional high potassium cardioplegic solution in 24-h cold storage of hamster hearts. Hexanol, a more potent arresting agent than ethanol, might be a more suitable alcohol. METHODS. Rat hearts were arrested and stored for 18 h at 4 degrees C with an ethanol (3 vol% = 510 mmol/liter) or 1-hexanol (4 mmol/liter) and pyruvate (10 mmol/liter) cardioplegic solution, St. Thomas' Hospital solution and Stanford solution and subsequently reperfused for 1 h at 35 degrees C. In other groups of hearts, basal oxygen consumption and rest intracellular calcium (Indo 1 technique) were evaluated during ethanol-, hexanol- and potassium-induced cardiac arrest. RESULTS. The percent recovery of left ventricular developed pressure and rate-pressure product were significantly better with the hexanol cardioplegic solution (67 +/- 21% and 58 +/- 19%, respectively; p < 0.05 for all comparisons) compared with the ethanol (10 +/- 7% and 5 +/- 4%), St. Thomas' Hospital (14 +/- 6% and 10 +/- 5%) and Stanford solutions (2 +/- 2% and 2 +/- 1%, respectively). Exclusion of ethanol and hexanol from storage solutions did not influence functional recovery. Values for oxygen consumption after 15- and 30-min ethanol- and hexanol-induced arrest were significantly lower than those after potassium-induced cardiac arrest. There was no difference in the rest intracellular calcium during cardiac arrest induced by the three arresting agents. CONCLUSIONS. A hexanol and pyruvate cardioplegic solution was more favorable than ethanol or conventional solutions for long-term cold storage of rat hearts. The beneficial effects of hexanol may have been provided in part by lower energy consumption during hexanol-induced cardiac arrest. These results may have implications for preservation of hearts for heart transplantation.