Celsior versus custodiol: early postischemic recovery after cardioplegia and ischemia at 5 degrees C

Beneficial Effects of RNS60 in Cardiac Ischemic Injury

RNS60 is a physically modified saline solution hypothesized to contain oxygen nanobubbles. It has been reported to reduce ischemia/reperfusion injury in a pig model of acute myocardial infarction. We investigated the effects of RNS60 during cardiac hypoxia in mice and as an additive to cardioplegic solution in rat hearts. ApoE^−/−LDLr^−/− mice were treated by intravenous injection of RNS60 or saline as a control while monitoring the ECG and post-hypoxic serum release of troponin T and creatine kinase activity. Hearts infused with Custodiol containing 10% RNS60 or saline as the control were subjected to 4 h of 4 °C preservation, followed by an assessment of myocardial metabolites, purine release, and mechanical function. RNS60 attenuated changes in the ECG STU area during hypoxia, while the troponin T concentration and creatine kinase activity were significantly higher in the serum of the controls. During reperfusion after 4 h of cold ischemia, the Custodiol/RNS60-treated hearts had about 30% lower LVEDP and better dp/dt_max and dp/dt_min together with a decreased release of purine catabolites vs. the controls. The myocardial ATP, total adenine nucleotides, and phosphocreatine concentrations were higher in the RNS60-treated hearts. This study indicates that RNS60 enhances cardioprotection in experimental myocardial hypoxia and under conditions of cardioplegic arrest. Improved cardiac energetics are involved in the protective effect, but complete elucidation of the mechanism requires further study.

Celsior® crystalloid cardioplegia versus standard hyperkalemic normothermic blood cardioplegia: Analysis of myocardial protection in elective mitral valve repair

INTRODUCTION

With the increase and refinement of video assisted mitral valve surgery, cristalloïd cardioplegia started regaining popularity. The aim of our study was to evaluate the effectiveness of Celsior^®, a crystalloid cardioplegic solution, on myocardial protection in elective surgical mitral valve repair in comparison to blood based hyperkalemic cardioplegia.

METHODS

In this observational retrospective study, all consecutive elective isolated surgical mitral valve repair where Celsior^® or normothermic hyperkalemic blood cardioplegia were used were included. Primary endpoint was any sign of myocardial protection failure (troponin levels, need for inotropic or mechanical support, rhythm disturbances, mortality). Secondary endpoint was Celsior^® safety (allergic reactions, bleeding, organ toxicities).

RESULTS

From January 2009 to August 2016, 382 patients underwent elective isolated mitral valve repair in whom normothermic hyperkalemic blood cardioplegia (n = 181) or Celsior^® (n = 201) were used. There were no statistically significant differences in baseline characteristics including Euroscore 2. Peak troponin (pg/ml) release and 30-days mortality were not statistically different. Need for cardioversion was significantly more frequent in the Celsior^® group (47% vs 13%, p < 0.001). There was no statistical difference in post-operative atrial fibrillation, permanent pacemaker implantation, reoperation for bleeding, transfusion, acute kidney injury, haemoglobin at discharge or length of stay. No allergic reaction to Celsior^® occurred.

CONCLUSION

Effective myocardial protection was achieved with the Celsior^® cardioplegic solution with no unexpected toxicity. Celsior^® may be an efficacious and safe cardioprotective strategy in mitral valve repair.

The Use of Histidine-tryptophan-ketoglutarate Solution as a New Storage Medium for the Avulsed Tooth

INTRODUCTION

Histidine-tryptophan-ketoglutarate (HTK) is a preservation solution used for organ transplantation. The physiological pH and osmolality of this solution are known to facilitate cell proliferation and cell membrane stabilization. The purpose of the present study was to investigate the efficacy of several concentrations of HTK solution as a storage medium for avulsed teeth.

METHODS

Cultured human periodontal ligament cells were stored in different concentrations of HTK solutions. After 1, 3, 6, 12, 24, 48, and 72 hours, cell viability was assessed using the Cell-Counting Kit-8 (Dojindo Molecular Technologies, Kumamoto, Japan) and LIVE/DEAD (Invitrogen, Carlsbad, CA) assay. Cell response of the most effective concentrations of HTK solution were further analyzed by gene expression profiling, and their cell viability was compared with other storage media.

RESULTS

The highest cell viability was observed in 50% HTK solution in various concentrations of HTK solution (P < .05). In periodontal ligament cells stored in 50% HTK solution for 3 hours, the expression of genes related to angiogenesis, the inflammatory response, and cell proliferation was increased compared with the control. Compared with other storage media, the highest cell viability was observed in 50% HTK solution.

CONCLUSIONS

Our study suggests that 50% HTK solution containing cell culture medium represents a suitable storage medium for avulsed teeth.

Myocardial protection in on-pump coronary artery bypass grafting surgery: analysis of the effectiveness of the use of retrograde Celsior®

BACKGROUND

We analyzed the adequacy of the myocardial protection achieved with a single dose of retrograde crystalloid Celsior®, compared with an accepted standard (microplegia), in on-pump coronary artery bypass grafting surgery (CABG).

METHODS

This was a retrospective comparative clinical study conducted in a single institution that included all the patients operated on who had elective isolated on-pump CABG, from March 2006 to June 2014. We evaluated maximum postoperative troponin T (TnT) as a marker of myocardial damage, adjusted for possible confounders using propensity score matching. We also analyzed markers of recovery of myocardial function, and the safety of the intravenous use of Celsior®.

RESULTS

During the study period, 261 patients were included, divided in two groups: (a) continuous retrograde blood-based microplegia (114 patients); (b) retrograde single-dose crystalloid Celsior® (147 patients). The propensity score adjusted maximum TnT was significantly lower in the Celsior group [average treatment effect = -0.55 ng/dl; 95% confidence interval (CI) -1.10 to -0.1 ng/dl; p = 0.048]. There were no differences in the postoperative use of intra-aortic balloon of counterpulsation or in the requirements of high-dose inotropic medications. In-hospital mortality was equivalent in both study groups ( p = 0.73); surgical re-exploration because of bleeding was equivalent ( p = 0.37). There were no differences in prolonged mechanical ventilation ( p = 0.65) and intensive care unit length of stay ( p = 0.87).

CONCLUSION

An isolated single dose of retrograde Celsior® may be an effective and safe myocardial protection strategy in on-pump CABG.

Hearts during ischemia with or without HTK-protection analysed by dielectric spectroscopy

OBJECTIVE

We investigated canine hearts during ischemia after aortic cross clamping (UI, n  =  20) and after HTK-cardioplegia (HTK, n  =  24) at 35 °C, 25 °C, 15 °C, and 5 °C with the aim to compare tissue changes caused by the activity of anaerobic metabolism(AAM), cell membrane destruction(CD), and gap junction uncoupling(GJU).

APPROACH

We measured continuously the complex dielectric spectrum(DS), ATP- and lactate content, extracellular pH, and rigor contracture. To identify changes in DS caused by AAM, CD, and GJU we performed additional experiments on the gap junction-free skeletal muscle. We used heart model simulations to calculate the effect of temperature.

MAIN RESULTS

AAM affected the DS at 10 MHz and we found a strong correlation between DS and the proton concentration with a maximum of DS at 10 mmol g^-1 dry weight in ATP-concentration. The time of GJU was detected by a characteristic increase in DS and CD by a characteristic decrease at 13 kHz. In comparison to UI, GJU, AAM and CD were delayed by HTK and by hypothermia, indicating a minimization of energy consumption and an improved preservation of tissue structure.

SIGNIFICANCE

The novel findings were that in UI at 5 °C GJU occurred earlier and AAM remained constant, indicating a less effective preservation in UI by deep hypothermia in contrast to HTK.

The Bologna experience with the Thoraflex™ hybrid frozen elephant trunk device

ABSTRACT 

Background: We present our initial experience with the frozen elephant trunk using a Thoraflex™ hybrid device for the treatment of the complex thoracic aorta lesions. Materials & methods: Between March 2013 and March 2014, ten patients underwent thoracic aorta surgery using the frozen elephant trunk approach with the Thoraflex hybrid device. Indications for surgery were: residual type A chronic dissection (eight patients), degenerative aneurysm (one patient) and type B chronic aortic dissection (one patient). Selective antegrade cerebral perfusion and moderate hypothermia were used in all cases. Results: In-hospital mortality was 0% and no patients presented with paraplegia, paraparesis or major neurological events. One patient experienced transient ischemic attack. Two patients underwent reoperation for bleeding. All postoperative angiography CT scans confirmed the desired results. Conclusion: Our initial experience demonstrated excellent early results. The Thoraflex hybrid prosthesis with the four-branched arch graft increases the spectrum of techniques available for the surgeon in the treatment of complex diseases of the thoracic aorta.

Preservation of the donor heart: from basic science to clinical studies

The methods of donor heart preservation are aimed at minimizing graft dysfunction caused by ischaemia-reperfusion injury (IRI) which inevitably occurs during the ex vivo transport interval. At present, the standard technique of heart preservation is cardiac arrest followed by static cold storage in a crystalloid heart preservation solution (HPS). This technique ensures an acceptable level of heart protection against IRI for <6 h. In clinical trials, comparable levels of myocardial protection against IRI were provided by various HPSs. The growing shortage of donor hearts is one of the major factors stimulating the development of new techniques of heart preservation. Here, we summarize new HPS formulations and provide a focus for optimization of the composition of existing HPSs. Such methods of donor heart preservation as machine perfusion, preservation at sub-zero temperature and oxygen persufflation are also discussed. Furthermore, we review experimental data showing that pre- and post-conditioning of the cardiac graft can improve its function when used in combination with cold storage. The evidence on the feasibility of cardiac donation after circulatory death, as well as the techniques of heart reconditioning after a period of warm ischaemia, is presented. The implementation of new techniques of donor heart preservation may contribute to the use of hearts from extended criteria donors, thereby expanding the total donor pool.

Custodiol for myocardial protection and preservation: a systematic review

INTRODUCTION

Custodiol cardioplegia is attractive for minimally invasive cardiac surgery, as a single dose provides a long period of myocardial protection. Despite widespread use in Europe, there is little data confirming its efficacy compared with conventional (blood or crystalloid) cardioplegia. There is similar enthusiasm for its use in organ preservation for transplant, but also a lack of data. This systematic review aimed to assess the evidence for the efficacy of Custodiol in myocardial protection and as a preservation solution in heart transplant.

METHODS

Electronic searches were performed of six databases from inception to October 2013. Reviewers independently identified studies that compared Custodiol with conventional cardioplegia (blood or extracellular crystalloid) in adult patients for meta-analysis; large case series that reported results using Custodiol were analyzed. Next, we identified studies that compared Custodiol with other organ preservation solutions for organ preservation in heart transplant.

RESULTS

Fourteen studies compared Custodiol with conventional cardioplegia for myocardial protection in adult cardiac surgery. No difference was identified in mortality; there was a trend for increased incidence of ventricular fibrillation in the Custodiol group that did not reach statistical significance. No difference was identified in studies that compared Custodiol with other solutions for heart transplant.

CONCLUSIONS

Despite widespread clinical use, the evidence supporting the superiority of Custodiol over other solutions for myocardial protection or organ preservation is limited. Large randomised trials are required.

Myocardial damage following cardiac surgery: comparison between single-dose Celsior cardioplegic solution and cold blood multi-dose cardioplegia

Myocardial protection during cardiac surgery can be accomplished by different cardioplegic solutions. The aim of this study was to assess myocardial damage after heart valve surgery performed with myocardial protection of a single dose of Celsior cardioplegia or with repeated cold blood cardioplegia. After the stratification of 139 valvular patients by means of matching according to cross-clamp and cardiopulmonary bypass time, 32 patients were retained for comparison (16 patients received Celsior and 16 patients received cold blood cardioplegia). Creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) release were evaluated until six days after the operation. Pre-operative characteristics were similar in both groups. In the Celsior group, CK-MB and cTnI values were significantly higher from the first up to the sixth post-operative day. Peak cTnI values were 19.4 ± 13.4 and 9.7 ± 7 ng/mL (p=0.01) in the Celsior and the Cold Blood group, respectively. Peak CK-MB values were 79.6 ± 58.8 and 45.9 ± 20.6 U/L (p=0.07) in the Celsior and the Cold Blood group, respectively. Cold blood cardioplegia reduces perioperative myocardial damage compared to the Celsior solution in elective cardiac valve operations.

A novel method of measuring cardiac preservation injury demonstrates University of Wisconsin solution is associated with less ischemic necrosis than Celsior in early cardiac allograft biopsy specimens

BACKGROUND

No consensus exists on the optimal heart preservative solution (HPS) for cardiac allograft preservation. The significance of varying degrees of acute ischemic necrosis (AIN) in early transplant biopsy specimens is unknown. We investigated the effects of HPS on early cardiac histopathology by developing a novel grading system of AIN.

METHODS

A retrospective review of our institutional database of orthotopic heart transplants (OHT) identified hearts preserved with University of Wisconsin (UW) or Celsior solutions. AIN severity was graded on early post-transplant biopsy specimens. Primary stratification was by HPS. Multivariable models examined mortality, AIN grade, primary graft dysfunction (PGD), and right heart failure (RHF).

RESULTS

From 1996 to 2010, 42 of 174 adult OHTs were preserved with UW and 132 with Celsior, from which 431 biopsy specimens were reviewed. UW and Celsior had similar 30-day (p = 0.79) and 1-year mortality (p = 0.92). Celsior was associated with significantly more AIN on the first (p = 0.02) and second (p = 0.04) specimens and persisted on multivariable analysis for the first (odds ratio, 2.93; 95% confidence interval, 1.26-6.83; p = 0.01) and second biopsy specimen (2.08; 0.99-4.34; p = 0.05). When stratified by AIN score, 30-day and 1-year mortality were similar (p > 0.05). Adjusted analysis showed increasing AIN score on the first biopsy was strongly associated with an increased incidence of PGD (1.59; 1.02-2.47; p = 0.04) and RHF (2.45; 1.14-5.27; p = 0.02).

CONCLUSIONS

Our grading system provides a simple, reproducible method for determining AIN. UW is associated with less AIN than Celsior solution. Early biopsy ischemia is associated with PGD and RHF. AIN may have prognostic significance and its routine evaluation should be considered.

Organ storage with University of Wisconsin solution is associated with improved outcomes after orthotopic heart transplantation

BACKGROUND

Despite significant advances in cardiac allograft preservation, the optimal preservative solution is unknown. We evaluated the impact of the most commonly used solutions in the USA, the University of Wisconsin solution (UW) and Celsior solution (CS), on outcomes after orthotopic heart transplantation (OHT).

METHODS

We retrospectively reviewed adult OHT recipients in the United Network for Organ Sharing (UNOS) database. Primary stratification was by preservation solution. The primary end-point was short-term survival (30 days and 1 year). Secondary end-points included common post-operative complications. Subgroup analysis was performed in high-risk allografts (donor age >50 years or ischemic time >4 hours). Risk-adjusted multivariate Cox proportional hazard regression was used to assess survival.

RESULTS

From 2004 to 2009, 4,910 patients (3,107 UW and 1,803 CS) with sufficient preservation solution information for analysis underwent OHT. Baseline characteristics were well-matched between the two groups. UW was associated with a small but significantly improved survival compared with CS at 30 days (96.7% vs 95.4%, p = 0.02) and 1 year (89.6% vs 87.0%, p < 0.01). These survival differences persisted on multivariate analysis at 30 days (HR 1.47 [1.02 to 2.13], p < 0.05) and 1 year (HR 1.40 [1.14 to 1.73], p < 0.01). In the 1,455 patients with high-risk allografts, preservation with UW was associated with improved survival compared with CS at 30 days (94.3% vs 91.3%, p < 0.01) and at 1 year (84.2% vs 80.19%, p < 0.01), a difference that was significant according to multivariate Cox analysis at 30 days (HR 2.29 [1.39 to 3.76], p < 0.01) and 1 year (HR 1.61 [1.17 to 2.21], p < 0.01).

CONCLUSIONS

Preservation with UW solution is associated with improved short-term survival compared with CS. Patients undergoing OHT with high-risk allografts have a similar survival benefit.

Histidine-tryptophan-ketoglutarate or celsior: which is more suitable for cold preservation for cardiac grafts from older donors?

BACKGROUND

The growing number of patients awaiting heart transplantation, coupled with the worldwide donor shortage, has led to increased use of marginal organs, specifically hearts from older donors. This study compared the protective effects of two widely used preservation solutions, histidine-tryptophan-ketoglutarate (HTK) and Celsior (CEL; Sangstat Medical, Menlo Park, CA), for ischemia-reperfusion injury using a rat heterotopic heart transplantation model with older donors.

METHODS

The hearts were excised from 16- and 80-week-old Lewis donor rats, stored in HTK, CEL, or saline for 6 hours and heterotopically transplanted into syngenic young Lewis recipients. Serum troponin I and creatine phosphokinase, graft infiltrating cells, graft apoptosis, graft proinflammatory messenger ribonucleic acid levels, and adenosine monophosphate-activated protein kinase phosphorylation were analyzed 3, 6, and 12 hours after reperfusion as markers of graft injury. Tissue adenosine triphosphate levels were measured after cold storage for 0, 6, 12, and 18 hours.

RESULTS

The HTK and CEL reduced injury comparably in grafts from young donors. The recipients of grafts from older donors and stored in HTK for 6 hours had lower levels of serum troponin I and creatine phosphokinase, less upregulation of the messenger ribonucleic acid for interleukin-6, intercellular adhesion molecule-1, and tumor necrosis factor-α, fewer infiltrating cells, less apoptosis, and less phosphorylated adenosine monophosphate-activated protein kinase than recipients of grafts stored in CEL. Adenosine triphosphate levels in the hearts stored in HTK were significantly higher than those stored in CEL or saline.

CONCLUSIONS

Cold storage in HTK exhibited superior protective effects against ischemia-reperfusion injury of hearts from older donors in this rat transplantation model.

Sodium hydrosulfide improves the protective potential of the cardioplegic histidine buffer solution

Since H(2)S has an emerging role as a cardioprotector, we hypothesized that NaHS addition to the new cardioplegic histidine buffer solution (HBS) could improve its cardioprotective potential. Male Wistar-Han rat hearts were divided in 4 groups: i) control, ii) perfusion control (perfusion only), iii) 6h ischemia in HBS or in a modified-HBS with 100 μM of NaHS, a H(2)S donor, (HBSM) and iv) as iii followed by 30 min reperfusion. During ischemia, aliquots of the cardioplegic solution were collected for NMR analysis. Heart mitochondria respiration and transmembrane potential were measured after ischemia or after ischemia followed by reperfusion. Proteins involved in the apoptotic signaling pathway were also quantified in both mitochondrial and tissue samples. Cardiac mechanic performance was evaluated by measuring the heart rate and the left ventricular pressure. In HBSM-preserved hearts, a) glucose consumption increased as well as lactate and alanine production during ischemia, b) heart mitochondria presented an improved phosphorylative efficiency, including decreased phosphorylative lag phase for complex I and complex II substrates, c) mitochondrial and tissue p53, Bax and caspase-9 were lower and d) there was a more positive atrial chronotropic response than in HBS-preserved hearts. We concluded that the addition of NaHS to HBS enhances glycolysis during ischemia, decreases mitochondrial dysfunction, especially by preserving the phosphorylative system, prevents apoptosis and during ischemia/reperfusion.

Superior myocardial preservation with HTK solution over Celsior in rat hearts with prolonged cold ischemia

BACKGROUND

Increasing allograft ischemic time is a significant risk factor for mortality following heart transplantation (HTx). The purpose of this study was to evaluate the protective effects of histidine-tryptophan-ketoglutarate (HTK) and Celsior (CEL) using a rat HTx model with prolonged cold storage.

METHODS

The hearts were excised from donor rats, stored in cold preservation solution for either 6 or 18 hours, and heterotopically transplanted into syngeneic recipients. Serum creatine phosphokinase (CPK), serum troponin I, graft-infiltrating cells, graft mRNA levels for inflammatory mediators, and tissue adenosine triphosphate (ATP) levels were analyzed, as markers of graft injury.

RESULTS

The recipients of grafts stored in HTK for 18 hours of prolonged cold ischemia had lower levels of serum CPK and tissue malondialdehyde, less upregulation of the mRNAs for IL-6 and inducible nitric oxide synthase, less apoptosis, and higher ATP levels than those receiving grafts stored in CEL and Saline. Cardiac contraction 3 hours after reperfusion was observed in 43% of the cardiac grafts stored in HTK for 18 hours, while no cardiac wall movement was seen in grafts stored in either saline or CEL.

CONCLUSION

Cold storage in HTK exhibited superior protective effects against prolonged cold ischemia in a syngeneic rat transplantation model.

[Solutions for organ preservation and other cardioplegic liquid formulations. Role of the hospital pharmacist]

Solid organ transplantation is an increasing need and a well-established activity which requires maintaining the quality of the transplant from procurement through the entire, storage, transport and graft procedure. Solutions for organ preservation play a key role in this procedure, by minimizing the deleterious effects of both ischemia and reperfusion. As such, their qualitative and quantitative compositions have to be optimized and validated. The development strategy and formulations proposed for these solutions are analyzed in this review as well as the results of the clinical studies which have set up the relevant pharmacological and physicochemical criteria. The French regulatory status of these products is also discussed. A clear distinction has to be made between solutions for organ preservation which are classified as produits thérapeutiques annexes (therapeutic ancillary products) and cardioplegic liquid formulations which are considered as medicinal products and are subject to marketing approval. Finally, the roles of the hospital pharmacist in the evaluation, selection, purchase and proper use of these products are described.

[An experimental organ model for magnetic resonance imaging]

The investigation of reperfusion of organs after an ischaemic phase is of great interest in transplantation medicine. This work presents an experimental organ model for the examination of isolated canine livers by means of magnetic resonance imaging in reperfusion experiments. The perfusion of the organs inside a perfusate container in the scanner's head coil was performed with approximately physiological conditions for 1.5 hours. The pumps for the perfusate circulation were installed outside the scanner's room, where oxygenation and heating of the perfusate was also performed. In the MR examinations, T1- and T2-weighted sequences could be used to display the morphology of the organs and the spatial perfusion distribution after administration of contrast media. The images revealed oedema development during reperfusion and an inhomogenous perfusion distribution. Thus, the model allows for the non-invasive investigation of morphology and perfusion distribution in isolated reperfused organs.

Elective cardiac surgery using Celsior or St. Thomas No. 2 solution: a prospective, single-center, randomized pilot study

OBJECTIVE

Celsior is a crystalloid solution specifically designed for solid-organ transplantation. Due to its advanced combination of solutes, we wanted to evaluate its safety, efficacy, and possible benefits when used as blood cardioplegia in elective cardiac surgery in a single-center, randomized, controlled clinical trial, comparing its performance with a well-established cardioplegic solution.

METHODS

Patients programmed for aortic valve replacement were randomized to receive either St. Thomas No. 2 or Celsior as blood cardioplegia with the same administration protocol. Intraoperative and postoperative variables concerning myocardial protection were registered and compared.

RESULTS

A total of 60 patients were enrolled and randomized (Celsior, 30; St. Thomas, 30). There were no significant differences in baseline and preoperative variables. Volume of cardioplegic solution, number of administrations needed and the amount of potassium added were similar in both groups. Patients in the Celsior group showed a higher incidence of spontaneous sinus rhythm after myocardial ischemia (77% vs 40%, p=0.004) and fewer patients required defibrillation (17% vs 43%, p=0.024) for ventricular reperfusion arrhythmias. Postoperatively, there were no significant differences in troponin I release, inotropic and vasopressor drug support, ICU stay, and postoperative evolution. There were no deaths in the study.

CONCLUSIONS

Celsior solution used as blood cardioplegia is effective and seems to be safe in elective aortic valve replacement when compared in this pilot study with a standard cardioplegic solution used worldwide. Fast return to sinus rhythm and lower incidence of reperfusion arrhythmias in the Celsior group may reflect a better myocardial protection during cardioplegic arrest. More investigation is needed to elucidate its performance in elective surgery.

High-risk heart grafts: effective preservation with Celsior solution

Celsior solution has already proved effective in heart graft preservation because it reduces myocardial edema, prevents free radical damage, and limits calcium overload. The aim of this study was to evaluate the effectiveness of Celsior solution as myocardial protection in high-risk transplantation. Hospital charts and follow-up data of 200 consecutive heart recipients (162 males, 38 females, mean age 47.4 +/- 12.6 years) were reviewed. Patients were divided into two groups: group A (73 patients) included recipients of high-risk grafts (at least two of the following: age >45; female sex; high preretrieval inotropic support, viz. dobutamine or dopamine >10 microg/kg per minute and/or infusion of norepinephrine regardless of its dosage; size mismatch >20%; ischemia time >180 min) and group B (127 patients) included recipients of standard grafts. Quality of preservation was assessed through enzyme release, echocardiographic evaluation, the need for inotropic support or pacemaker, and histology of biopsy samples. Hospital and 1-year mortality were also evaluated. Comparisons between the two groups were made through univariate analysis. Study groups proved homogeneous as to recipient age, pretransplant cardiomyopathy, status at transplantation, mean panel reactive antibodies, and redo cardiac surgery. Hospital mortality was 8% (11% vs 6.3%, P = 0.18) while 1-year mortality reached 12% (15.1% vs 10.2%, P = 0.6) without significant difference between groups. Graft performance as described by the need for inotropic support and/or pacemaker as well as echocardiography (left and right ventricular ejection fraction) proved comparable. There were no significant differences as to histology findings and patterns of enzyme release. Celsior provides optimal myocardial preservation in both standard and high-risk procedures. Such advances help to enhance donor pool expansion.

A peroxynitrite decomposition catalyst: FeTPPS confers cardioprotection during reperfusion after cardioplegic arrest in a working isolated rat heart model

Heart transplant is considered to be an extremely severe ischemia-reperfusion sequence. Post-ischemic dysfunction triggers multiple processes especially oxidative stress, but the mechanisms remain unclear. Free radical interactions lead to peroxynitrite generation, which seems to be involved in early post-transplant heart failure. The aim of this study was to evaluate the potential impact of a peroxynitrite decomposition catalyst: FeTPPS (5,10,15,20-tetrakis-[4-sulfonatophenyl]-porphyrinato-fer[III]) and pyruvate on myocardial functional recovery after cardioplegic arrest using an experimental protocol in rat hearts. Isolated working rat hearts were subjected to ischemia (4 h at 4 degrees C in cardioplegic solutions), followed by 45 min of reperfusion. Four groups were constituted: control, pyruvate: (2 mm) added to cardioplegic and Ringer-lactate solutions, FeTPPS: (10 microm) perfused during the reperfusion, and a combination of both treatments. Lactate dehydrogenase (LDH) activity was assessed during the reperfusion to evaluate the level of cardiac injury. Oxidative stress was evaluated on heart slices using a fluorescent probe: dihydroethidium, and the collagen content was assessed using picro-Sirius coloration. Global post-ischemic recovery in the control group was about 35% of pre-ischemic values. Results showed that addition of pyruvate led to an increase in myocardial function and to a decrease in LDH activity released during the reperfusion. FeTPPS protected against injury after cardioplegic arrest during reperfusion. No additive effect of the two treatments (pyruvate + FeTPPS) was observed. The collagen content was better preserved in the FeTPPS group than in the control and pyruvate groups. In conclusion, this study shows that peroxynitrite plays an important role in the functional and cellular alterations associated with cardiac ischemia-reperfusion sequences and confirms that pyruvate helped to preserve myocardial function. The use of the peroxynitrite decomposition catalyst (FeTPPS) may help to improve myocardial preservation during a prolonged ischemia sequence.

A Comparative Study of Cardiac Preservation with Celsior or University of Wisconsin Solution with or without Prior Administration of Cardioplegia

BACKGROUND

We have previously reported the cardiac functional and metabolic benefits of administration of extracellular-type cardioplegia before preservation with University of Wisconsin solution. Celsior solution was designed to be used both as an arresting solution and a storage solution for heart transplantation. The objective of the present study is to compare cardiac function of hearts arrested and preserved with Celsior solution to hearts arrested with cardioplegia followed by preservation with UW solution.

METHODS

Rabbit hearts were divided into 4 groups: in the Celsior group, hearts were arrested and preserved with Celsior solution; in the C-Celsior group, hearts were arrested by an extracellular-type cardioplegia and preserved with Celsior solution; in the UW group, hearts were arrested and stored in University of Wisconsin solution; and, in the C-UW group, hearts were arrested with extracellular-type cardioplegia and stored in University of Wisconsin solution. After 6 hours of preservation, cardiac function was measured using modified Frank-Starling curves in the isolated blood-perfused working heart.

RESULTS

Cardiac function in the Celsior group was inferior to that in both the C-UW group and UW group. The C-Celsior group demonstrated inferior cardiac function compared with the Celsior group (p < 0.01), whereas no significant difference was observed between the C-UW and UW groups.

CONCLUSIONS

Celsior solution did not surpass UW solution regardless of the use of cardioplegia. Further studies are required to develop optimal solution for use as both an arresting solution and a storage solution.

Low-Dose Histidine-Tryptophan-Ketoglutarate Solution for Myocardial Protection

The effect of histidine-tryptophan-ketoglutarate (HTK) solution for myocardial protection has been shown in experimental and clinical studies using long ischemic times and high dosages. In our study we compared myocardial protection in isolated coronary bypass with a short period of ischemia using low dosage HTK and cold crystalloid cardioplegia. Each group contained 21 coronary artery disease patients. Cardioplegic solutions were administered antegrade in 10 to 15 mL/kg in one shot. This dosage of HTK was lower than that mentioned in the literature. We measured malondialdehyde, lactate, creatine kinase, creatine kinase-MB, and troponin-I levels. Aortic clamping time in the HTK group 33.9 +/- 8.2 minutes, versus 36.2 +/- 11.3 minutes in the crystalloid cardioplegia group (P > .05). Levels of creatine kinase and malondialdehyde were lower in HTK group at 24 hours and 2 minutes, respectively. Lactate levels were lower in the crystalloid cardioplegia group at 2 minutes in the coronary sinus serum sample, but there were no statistically differences among ischemic serum markers in both groups. Only intervals between aortic clamping and cardiac arrest were statistically meaningful (HTK 63.3 +/- 14.7 seconds versus crystalloid cardioplegia 53.6 +/- 15.6 seconds, P = .044). Our study shows that use of low-dose HTK for short clamping time operations is as successful for myocardial protection as crystalloid cardioplegia. Longer times for fibrillation can be explained with the low levels of potassium in HTK solution, but this length did not cause a biochemical or clinical difference.

Cell Preservation in Reparative and Regenerative Medicine: Evolution of Individualized Solution Composition

The expanding complexity of biologics banked for therapeutic applications necessitates the development of improved preservation technologies for support of the emerging fields of reparative and regenerative medicine. Currently, a number of media or "solutions" are utilized for the preservation of biologics. Given the diversity of cell systems utilized in the regenerative medicine arena, we hypothesized that the development of unique (individualized) preservation solutions designed to meet the distinct molecular biological requirements of individual systems would provide for enhanced and extended preservation. To evaluate this hypothesis, coronary artery smooth muscle cells (CASMCs), coronary artery endothelial cells (CAECs), hepatic cells (C3A), and skeletal muscle cells (SKMCs) were hypothermically preserved for 2 to 7 days at 4 degrees C in either cell culture medium, University of Wisconsin Solution (UW or ViaSpan), or HypoThermosol (HTS) variants. Cells were then assayed for viability, using the alamarBlue assay as well as calcein-AM, subsequent to their return to normothermic (37 degrees C) temperatures for up to 5 days. CASMC viability was best maintained when preserved in HTS plus Trolox/EDTA, CAEC viability was highest when preserved in HTS plus Trolox, SKMCs stored in HTS plus Trolox/RGD demonstrated enhanced viability, and C3A cells were best preserved in HTS plus FK041. The data suggest that solution compositions that address the differences in cell death mechanisms limiting preservation efficacy can result in targeted improvement matched to specific cell types. These observations support the custom solution hypothesis of cell and tissue preservation.

Optimizing Donor Heart Outcome After Prolonged Storage With Endothelial Function Analysis and Continuous Perfusion

BACKGROUND

By minimizing tissue ischemia, continuous perfusion (CP) during organ transport may increase the safety of "marginal donors." My colleagues and I investigated whether an analysis of donor heart viability predicts recovery of grafts challenged with a 24-hour preservation interval.

METHODS

Dog hearts underwent cold static storage (CS) for 8 hours (n = 8) or 24 hours (n = 2) or CP for 24 hours with cold asanguinous, oxygenated solution (n = 8). Myocardial systolic and diastolic function and oxygen and lactate consumption were assessed at base line, during CP, and after Langendorff blood reperfusion. Base line endothelial function was evaluated by the percentage transcoronary change ([coronary sinus - aorta]/aorta) in myeloperoxidase and by platelet function and coronary flow reserve after 20 seconds of coronary artery occlusion. During CP, the endothelium was assessed by transcoronary protein release and coronary resistance. Edema was assessed by weight gain and histology.

RESULTS

Base line systolic and metabolic functions showed no relation to post-Langendorff function. Compared with CS, CP resulted in a greater recovery in systolic function (87% +/- 35% vs 65% +/- 15% of baseline; p = 0.05) and a shorter interval required for lactate consumption to exceed production (7.0 +/- 6.8 minutes vs 15.0 +/- 8.9 minutes; p = 0.06). Endothelial function was heterogeneous: coronary flow reserve, 2.7 +/- 0.7; percentage change in myeloperoxidase, -8.4% +/- 6.8%; and change in platelet function, 4.3% +/- 3.5%, as determined by thromboelastography angle at base line. Protein release during CP for 24 hours was 8.3 +/- 7.1 g. Two factors predicted more than 75% systolic pressure generation recovery: use of CP and normal endothelial function (p = 0.05; Fisher's exact test). However, CP led to edema according to histology, weight gain (72 +/- 29 g), and impaired diastolic function versus CS (end-diastolic pressure-volume relationship, 1.4 +/- 0.4 mm Hg/mL vs 0.8 +/- 0.3 mm Hg/mL; p = 0.08).

CONCLUSIONS

Better systolic function despite 16 hours' more preservation than cold storage corroborates the idea that CP supports aerobic metabolism at physiologically important levels. Viability analysis focused on endothelial function and identified organs that were able to tolerate this 24-hour preservation interval.

Monitoring of water content and water distribution in ischemic hearts

We determined water content and water distribution by fitting dielectric spectra of ischemic canine hearts between 5 MHz and 3 GHz with a newly developed model which describes heart cells and subcellular organelles as rotational ellipsoids filled with electrolyte enclosed by an isolating membrane. The fraction of dry material is modelled by spherical particles with a small dielectric permittivity. Free model parameters were water content, cell volume fraction, and the conductivity of the electrolytes. Resulting model parameters were compared to data from tissue desiccation and to conductivity changes produced by protons and lactate ions. We investigated hearts in two states: during ischemia after interruption of blood flow (pure ischemia, PI, n=5) and during ischemia after resuscitation with Tyrode's solution (IAR, n=14). The difference between water content determined by tissue desiccation and by dielectric spectroscopy was less than 0.5%. During 360 min of ischemia, water content in IAR decreased from 85+/-1.6% to 83+/-2.2% and in PI from 80+/-0.8% to 78+/-1.5%. Cellular volume fraction in IAR increased from 0.47+/-0.045 to 0.63+/-0.031 and in PI from 0.62+/-0.014 to 0.73+/-0.013, which is consistent with published morphometric data. After 180 min of ischemia, the increase of the cytosolic conductivity was 0.14+/-0.02 S/m as calculated from the dielectric spectrum and was similar to the conductivity increase which was roughly estimated on the basis of tissue lactate concentration. In conclusion, dielectric spectroscopy combined with our model analysis facilitates the monitoring of water content and distribution by means of nondestructive surface probes.