Cardiac storage with UW solution and glucose

Does University of Wisconsin solution harm the transplanted heart?

BACKGROUND

University of Wisconsin solution (UW) has been shown to be an effective preservative for the cardiac allograft. Recently, the high potassium content of UW has been implicated in causing coronary endothelial damage, allegedly contributing to development of cardiac allograft vasculopathy (CAV) and eventually to poorer survival.

METHODS

We examined our experience using UW for preservation of cardiac allografts between 1990 and 1994 (n = 94), and compared these to hearts preserved with the lower potassium-containing Stanford solution used at our center between 1986 and 1990 (n = 65). Indices of graft function, ischemic injury, CAV incidence, CAV severity, and survival were evaluated.

RESULTS

The 2 groups were similar in age, gender, diagnosis, donor inotropic support, donor-recipient weight ratio, incidence of acute graft failure, and cytomegalovirus seroconversion. UW-preserved hearts came from older donors (30.5 vs 24.1 years, p < .001), and were transplanted into more status 1 recipients (56% vs 22%, p < .001), consistent with current trends. Mean ischemic time of UW-preserved hearts was significantly longer (184 vs 155 minutes, p < .005) although time required to wean from bypass was less (45.5 vs 73.8 minutes, p < .001) and there was a trend towards less inotropic requirement. CPK-MB release was less with UW preservation (63 vs 87 microg/ dL, p = .001). Three years after transplantation, both groups were similar in the incidence of CAV (UW, 27.3%; STNF, 37.5%; p = 0.27), and also the severity of CAV (p = 0.78). Deaths attributed to CAV were equal in each group (UW, 11.4% vs STNF, 10.7%; p = 0.79). Kaplan-Meier survival analysis revealed equivalent survival curves (p = 0.26).

CONCLUSIONS

We conclude that UW is a safe and effective myocardial preservative, allowing longer ischemic times with equivalent graft function. Our data suggest that when UW is used for cardiac allograft preservation, both CAV and survival are comparable to the experience with other preservatives containing lower concentrations of potassium.

Pretreatment with a potassium-channel opener before prolonged cardiac storage: an evaluation in an experimental brain death model

BACKGROUND

Pretreatment with a potassium-channel opener has been shown to improve functional recovery after long-term cardioplegic arrest. We evaluated whether pretreatment with the potassium-channel opener cromakalim is beneficial in a more clinically relevant experimental model of brain death in the rabbit.

METHODS

Four groups of rabbits were studied in a 2 x 2 factorial experiment (n = 8 per group). Rabbits were subjected to a sham operation or 90 minutes of brain death induced by inflating a subdurally placed balloon. Thirty minutes before heart explantation, rabbits received either no pretreatment or an intravenous injection of cromakalim, 30 microg/kg. Hearts then received 5 hours' hypothermic storage in St. Thomas' Hospital solution and were assessed on a buffer-perfused isolated heart preparation. Hemodynamic recovery, coronary flow, and creatine kinase release were determined after 60 minutes of reperfusion.

RESULTS

Systolic function and diastolic function were significantly altered in hearts explanted from brain-dead rabbits compared with hearts from rabbits having a sham operation. Cromakalim pretreatment had no significant effect on poststorage systolic or diastolic function of hearts explanted from brain-dead or sham-operation rabbits. Further, cromakalim pretreatment did not affect coronary flow or overall creatine kinase release during reperfusion. CONCLUSIONS; In vivo pretreatment of brain-dead rabbits or anesthetized rabbits with an intravenous injection of cromakalim had no significant effect on functional recovery of or enzymatic release from explanted hearts after 5 hours' hypothermic storage and 60 minutes' reperfusion. These findings underscore the importance of clinically relevant experimental models.

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 degree, 4 degrees, 8 degrees, 12 degrees, or 16 degrees C) in a complete 2 x 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 degrees C or less than at 12 degrees C or more. The single preferred temperature was 4 degrees C, significantly better than 0 degree C with unmodified UWS, while similar to 0 degree and 8 degrees C with BDM. Adenine nucleotide values were decreased equally in the BDM and UWS hearts, but preservation was enhanced at 0 degree C compared with all warmer temperatures.

CONCLUSIONS

We conclude that 4 degrees 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 degrees C or less.

Adenosine pretreatment for prolonged cardiac storage. An evaluation with St. Thomas' Hospital and University of Wisconsin solutions

Adenosine pretreatment has been shown to be beneficial in several models of ischemia-reperfusion. We wished to evaluate whether adenosine pretreatment is cardioprotective for prolonged cardiac storage and whether the presence of adenosine in the storage media affects the results. Isolated rodent hearts were obtained from Sprague-Dawley rats, mounted on a Langendorff apparatus, instrumented with an intraventricular balloon, and ventricularly paced at 300 beats/min. Four groups of hearts were studied in a 2 x 2 factorial experiment (n = 8 to 12 per group). Hearts were subjected to normal perfusion or to solution supplemented with adenosine 50 mumol/L for 10 minutes followed by adenosine-free perfusion for 10 minutes. Hearts then were stored for 8 hours at 0 degrees C in either University of Wisconsin solution (adenosine 5 mmol/L) or St. Thomas' Hospital II solution (adenosine free). Adenosine pretreatment increased tissue levels of adenosine triphosphate before storage (p = 0.04). Nonfunction was less common after storage (1/19 versus 6/20 hearts, p < 0.05), and diastolic function was better preserved in the adenosine groups in the reperfusion phase (p = 0.01). The beneficial effects of adenosine pretreatment were independent of which storage solution was used. Developed pressure was increased (p < 0.05) and release of creatine kinase and lactate dehydrogenase was reduced (p < 0.0001) in hearts treated with University of Wisconsin solution compared with those treated with St. Thomas' Hospital solution. These studies suggest that adenosine pretreatment improves recovery after prolonged hypothermic storage and that the presence of adenosine in the preservation solution does not alter the results. The experiments provide further evidence that extended myocardial protection is better enhanced with University of Wisconsin solution than with St. Thomas' Hospital II solution.

Cardiac storage with University of Wisconsin solution and a nucleoside-transport blocker

Findings from previous investigations conducted at this institution and others have suggested that University of Wisconsin solution (UWS) is preferable for the prolonged hypothermic storage of hearts before transplantation. The benefit seen with UWS may in part be related to the inclusion of adenosine (5 mmol/L) in the UWS. To investigate whether further manipulations of adenosine metabolism might enhance myocardial protection, studies were initially conducted using cultured myocytes, followed by confirmatory experiments using isolated rat hearts. Cultured human ventricular myocytes (7 to 8 dishes/group) were stored for 12 hours at 0 degrees C in unmodified UWS or UWS supplemented with increasing concentrations (1 to 100 mumol/L) of the nucleoside-transport blocker p-nitrobenzylthioinosine. The adenosine triphosphate concentrations were found to be enhanced with nucleoside-transport inhibition, with the best results achieved with the 1- and 3-mumol/L groups (control, 3.37 +/- 0.41 nmol/micrograms DNA; UWS, 2.89 +/- 1.31 nmol/micrograms DNA; 1 mumol/L, 5.91 +/- 3.23 nmol/micrograms DNA; 3 mumol/L, 7.86 +/- 3.45 nmol/micrograms DNA; p < 0.05 versus control or UWS group). Isolated rodent hearts from Sprague-Dawley rats were prepared on a Langendorff apparatus with an intraventricular balloon and subsequently stored for 8 hours at 0 degrees C in unmodified UWS (13 hearts/group) or UWS supplemented with 1 or 3 mumol/L of p-nitrobenzylthioinosine (9 to 10 hearts/group).(ABSTRACT TRUNCATED AT 250 WORDS)