Cardioplegic Solution Research Articles

Custodiol versus extracellular crystalloid cardioplegia in mitral valve replacement in patients with low ejection fraction

Background The use of cardioplegia solution is aimed to avoid myocardial muscle damage, leading to poor contraction and abnormal increased release of cardiac biomarkers enzymes during cardiac arrest. It remains the primary method for myocardial protection against ischemia–reperfusion injury during cardiac surgery. Cardioplegia was first presented as an agent for hypothermic hyperkalemic arrest. Blood was then introduced as a vehicle to convey potassium to the heart. Histidine–tryptophan–ketoglutarate solution is safe and used as a single dose that can last for up to 3 h. Comparison between custodiol cardioplegia and cold blood cardioplegia still remains a big debate till now. Objective To compare the clinical outcomes of custodiol solution with cold blood cardioplegia in mitral valve replacement (MVR) with cardiac ejection fraction less than 45%. Patients and methods This single‑center randomized prospective study was carried out from January 2018 till June 2019 at Ain Shams University hospitals. Overall, 65 patients with poor left ventricular function undergoing mitral valve replacement were divided randomly according to type of myocardial protection into two groups: group A included 30 patients who received custodiol cardioplegia, and group B included 35 patients who received cold blood cardioplegia. Data from each group were collected and compared with each other. Results Baseline demographic and intraoperative data showed no significant difference between the two groups. The need for inotropic support, length of mechanical ventilation, and ICU stay were statistically nonsignificant between the two groups. There was a statistically significant difference regarding the rhythm upon declamping [ventricular fibrillation (VF) in 17 (56.7%) cases in group A and nine (25.7%) cases in group B (P=0.016)], and also there was a significant difference in times of defibrillation cardioversion (DC) shock given after declamping (P=0.005). Overall mortality shows a statistically nonsignificant difference. There is a significant difference in postoperative echo assessment for both groups [ejection fraction in group A: 53.17±7.73 compared with 49.06±7.170 in group B (P=0.031)], and there is also a difference in hemoglobin postoperatively, with 10.35±0.843 in group A compared with 10.88±0.798 in group B (P=0.013). Conclusion Cardiac arrest using custodiol cardioplegia is a good choice in mitral valve replacement with the advantage of giving only one dose of cardioplegia without interruption of the operation, and also it gives good postoperative echo results than cold blood cardioplegia. Its disadvantages are lower hemoglobin levels postoperatively and hyponatremia during bypass in comparison with cold blood cardioplegia.

Adipose stem cell secretome markedly improves rodent heart and human induced pluripotent stem cell-derived cardiomyocyte recovery from cardioplegic transport solution exposure.

Heart transplantation is a life-saving therapy for end-stage organ failure. Organ deterioration during transportation limits storage to 4 hours, limiting hearts available. Approaches ameliorating organ damage could increase the number of hearts acceptable for transplantation. Prior studies show that adipose-derived stem/stromal cell secretome (ASC-S) rescues tissues from postischemic damage in vivo. This study tested whether ASC-S preserved the function of mouse hearts and human induced pluripotent stem cell-derived cardiomyocytes (iCM) exposed to organ transportation and transplantation conditions. Hearts were subjected to cold University of Wisconsin (UW) cardioplegic solution ± ASC-S for 6 hours followed by analysis using the Langendorff technique. In parallel, the effects of ASC-S on the recovery of iCM from UW solution were examined when provided either during or after cold cardioplegia. Exposure of hearts and iCM to UW deteriorated contractile activity and caused cell apoptosis, worsening in iCM as a function of exposure time; these were ameliorated by augmenting with ASC-S. Silencing of superoxide dismutase 3 and catalase expression prior to secretome generation compromised the ASC-S cardiomyocyte-protective effects. In this study, a novel in vitro iCM model was developed to complement a rodent heart model in assessing efficacy of approaches to improve cardiac preservation. ASC-S displays strong cardioprotective activity on iCM either with or following cold cardioplegia. This effect is associated with ASC-S-mediated cellular clearance of reactive oxygen species. The effect of ASC-S on the temporal recovery of iCM function supports the possibility of lengthening heart storage by augmenting cardioplegic transport solution with ASC-S, expanding the pool of hearts for transplantation.

Investigation of myocardial protection during pediatric CPB: Practical experience in 100 Chinese hospitals.

Many measures have been proposed for myocardial protection in pediatric congenital heart surgeries, but little data is available for China. This study investigates myocardial protection strategies in pediatric cardiopulmonary bypass (CPB) throughout China. Online questionnaires were delivered to 100 hospitals in 27 provinces. The number of yearly on-pump pediatric cardiovascular surgeries in these hospitals varied greatly. About 91.0% of respondents believe that each surgery should have at least two perfusionists, while only 64.0% of hospitals actually met this requirement. For pediatric patients, crystalloid cardioplegia was more prevalent than blood-based cardioplegia. Histidine-tryptophan-ketoglutarate solution and St. Thomas crystalloid solution were dominant among crystalloid cardioplegia. Del Nido cardioplegia and St. Thomas blood-based cardioplegia ranked the top two in the popularity of blood-based cardioplegia. Dosages varied among different kinds of cardioplegia. In the choice of different cardioplegia, perfusionists mainly focused on myocardial protective effect and cost. Hypothermia of cardioplegia solution was maintained by ice buckets in 3/4 of the hospitals in this survey. In conclusion, the essence of myocardial protection management during pediatric CPB was cardiac arrest induced by cardioplegia under systemic hypothermia. However, there is no uniform standard for the type of cardioplegia, or dosages. Therefore, well-designed multicenter randomized controlled trials are warranted to provide tangible evidence for myocardial protection of cardioplegia in pediatric CPB.

Myocardial Protection by Retrograde Application of HTK Solution Compare with Cold Blood Cardioplegic Solution during Heart Valve Surgery

Objective: Cardioplegic solution is one important principle for adequate myocardial protection in cardiac surgery. Bretschneider’s histidine-tryptophan-ketoglutarate (HTK) solution is an intracellular solution while blood cardioplegia solution is an extracellular solution. Both have been used to preserve the myocardium. The present study compared between the two cardioplegic solutions for incidence of ventricular fibrillation after aortic clamp removal in double valve replacement (DVR) and tricuspid annuloplasty (TVA) to assess the effectiveness for myocardial protection. Materials and Methods: A retrospective study was conducted among patients who underwent DVR with TVA operations between January 1, 2013 and June 30, 2017 and divided in two groups at Queen Sirikit Heart Center of the Northeast. The medical records were searched for detailed demographics, preoperative status, operative technique, and post-operative hospital course. Results: Thirty-six patients were included in the present study, 18 patients received HTK solution, the others received blood cardioplegia. The demographic data presented no statistical difference between the two groups. Incidence of ventricular fibrillation after aortic clamp removal occurred in 10 patients (55.6%) in the HTK group, which was more than the cold blood group [five patients (27.78%)]. Cardiopulmonary bypass (CPB) and aortic cross clamp time in the cold blood group was significantly longer than in the HTK group (p<0.001). The peak of Trop-T and CK-MB within six hours after surgery tended to be downward after 24 hours and was not related to perioperative myocardial ischemia in the HTK group. No statistically difference was observed in postoperative outcome, ICU stay, or hospital stay. Conclusion: The use of HTK solution has no significant different outcome compared to conventional cold blood cardioplegia via retrograde route in DVR with TVA operation. There was no significantly different incidence of ventricular fibrillation and there was no evidence of postoperative myocardial infarction. CPB and aortic cross clamp time in the HTK group were shorter than in the cold blood cardioplegia significantly. Keywords: Cardioplegia, HTK, Custodiol, Ventricular fibrillation

Comparison of del Nido and histidine-tryptophan-ketoglutarate cardioplegic solutions in minimally invasive cardiac surgery

ObjectiveWe examined the safety and efficacy of del Nido cardioplegic solution compared with histidine-tryptophan-ketoglutarate cardioplegic solution in minimally invasive cardiac surgery. MethodsPatients who underwent minimally invasive cardiac surgery using del Nido or histidine-tryptophan-ketoglutarate from 2015 to 2019 were enrolled. Various clinical outcomes were compared between the groups. Postoperative laboratory findings including the levels of electrolytes, cardiac enzymes (creatine kinase-MB and troponin I), and serial blood lactate were also measured and compared. Based on 28 baseline covariates, propensity score matching was performed to reduce selection bias. ResultsAmong 766 patients, del Nido and histidine-tryptophan-ketoglutarate were used in 330 patients (43.1%) and 436 patients (56.9%), respectively. There were no significant intergroup differences in postoperative clinical outcomes and early adverse outcomes among 228 pairs of propensity score–matched patients. Immediate postoperative sodium levels were within the normal range in both groups without a significant difference (P = .50). However, peak creatine kinase-MB (median, 31.9 vs 37.7 ng/mL, P = .026) and troponin I (6.9 vs 9.1 ng/mL, P = .014) levels were significantly lower in the del Nido group. Linear regression analysis revealed a significant association between the peak cardiac enzyme levels and the cardiac ischemic time depending on the cardioplegia type, with lower cardiac isoenzymes for del Nido over histidine-tryptophan-ketoglutarate (P < .001) until the crossover point at the cardiac ischemic time over 100 minutes. ConclusionsIn comparison with histidine-tryptophan-ketoglutarate solution, del Nido solution seems to have acceptable safety and efficacy with good myocardial protection in minimally invasive cardiac surgery. Further studies focusing on complex surgeries requiring longer cardiac ischemic time are needed.

Use of del Nido Cardioplegia for Adult Heart Surgery: How Long Is Not Too Long?

The most apparent practical advantage of del Nido cardioplegia (DNC) is that it allows the surgeon a longer arrest period before a subsequent dose is needed, as opposed to the conventional St. Thomas' cardioplegia solution where the recommended ischemic time is ∼15-20 minutes. In this study, we explored the incidence of arrhythmia after cross-clamp removal as a surrogate for a safe myocardial ischemic time with the use of DNC in adult heart surgery. A total of 113 patients who had undergone heart valve repair and/or replacement surgery at the National University Hospital, Singapore, were investigated. This single-center retrospective study was conducted on a population where DNC had been used for myocardial protection between January 2017 and April 2019. Cardioplegia ischemic time interval groups were not significant predictors of postoperative arrhythmia, defibrillation, and intraoperative intra-aortic balloon pump usage. Crude comparison of postoperative outcomes showed no significant differences in any other postoperative variables, including mortality and total hospital stay. From the results of the present study, it appears that there is no optimal ischemic time interval for the administration of DNC within a 120-minute time period. It is likely that DNC has a redosing interval of, and may provide adequate myocardial protection, for up to 120 minutes.

Long-Term Protective Effects of Single-Dose Cardioplegic Solutions in Cell Culture Models.

Despite the popularity of single-dose cardioplegic techniques, the time window and targeted population for successful reperfusion remain unclear. We tested currently available techniques based on cell viability and integrity to demonstrate long-term cardioprotection and clarify whether these solutions were performed on neonatal/adult endothelium and myocardium by examining different cell lines. Cell viability with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test proliferation assay and membrane integrity with the lactic dehydrogenase (LDH) cytotoxicity test were documented in a cell culture/microscopy setting on adult (human umbilical vein endothelium [HUVEC]), neonatal (H9C2-cardiomyocytes), and myofibroblast (L929) cell lines. Apoptotic cell activity and necrosis were evaluated by acridine orange/propidium iodide (AO/PI) staining. Twenty-four hours after seeding, cells were incubated in control (Dulbecco's modified Eagle), St. Thomas and blood cardioplegia (4:1), histidine-tryptophan-ketoglutarate (HTK), and del Nido solutions at 32°C followed by an additional 6, 24, and 48 hours in standard conditions (37°C, 5% CO2). Experiments were repeated eight times. In MTT cell viability analysis, HTK protection was significantly better than the control medium in L929 cell lines at 48th hours follow-up and acted markedly better on the HUVEC cell line at 24th and 48th hours. del Nido and HTK provided significantly better protection on H9C2 (at 24th and 48th hours). Apoptotic and necrotic cell scoring as a result of AO/PI staining was found consistent with MTT results. The LDH test demonstrated that the level of cell disruption was significantly higher for St. Thomas and blood cardioplegia in H9c2 cells. Experimental studies on cardioplegia aimed at assessing myocardial protection use time-consuming and often expensive approaches that are unrealistic in clinical practice. We have focused on identifying the most effective cell types and the direct consequences of different cardioplegia solutions to document long-term effects that we believe are the most underestimated ones in the cardioplegia literature.

Long-Term Protective Effects of Single-Dose Cardioplegic Solutions in Cell Culture Models

Despite the popularity of single-dose cardioplegic techniques, the time window and targeted population for successful reperfusion remain unclear. We tested currently available techniques based on cell viability and integrity to demonstrate long-term cardioprotection and clarify whether these solutions were performed on neonatal/adult endothelium and myocardium by examining different cell lines. Cell viability with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test proliferation assay and membrane integrity with the lactic dehydrogenase (LDH) cytotoxicity test were documented in a cell culture/microscopy setting on adult (human umbilical vein endothelium [HUVEC]), neonatal (H9C2-cardiomyocytes), and myofibroblast (L929) cell lines. Apoptotic cell activity and necrosis were evaluated by acridine orange/propidium iodide (AO/PI) staining. Twenty-four hours after seeding, cells were incubated in control (Dulbecco’s modified Eagle), St. Thomas and blood cardioplegia (4:1), histidine–tryptophan–ketoglutarate (HTK), and del Nido solutions at 32°C followed by an additional 6, 24, and 48 hours in standard conditions (37°C, 5% CO2). Experiments were repeated eight times. In MTT cell viability analysis, HTK protection was significantly better than the control medium in L929 cell lines at 48th hours follow-up and acted markedly better on the HUVEC cell line at 24th and 48th hours. del Nido and HTK provided significantly better protection on H9C2 (at 24th and 48th hours). Apoptotic and necrotic cell scoring as a result of AO/PI staining was found consistent with MTT results. The LDH test demonstrated that the level of cell disruption was significantly higher for St. Thomas and blood cardioplegia in H9c2 cells. Experimental studies on cardioplegia aimed at assessing myocardial protection use time-consuming and often expensive approaches that are unrealistic in clinical practice. We have focused on identifying the most effective cell types and the direct consequences of different cardioplegia solutions to document long-term effects that we believe are the most underestimated ones in the cardioplegia literature.

Hypothermic preservation of rat hearts using antifreeze glycoprotein.

Antifreeze proteins are an effective additive for low-temperature preservation of solid organs. Here, we compared static hypothermic preservation with and without antifreeze glycoprotein (AFGP), followed by nonfreezing cryopreservation of rat hearts. The heart was surgically extracted and immersed in one of the cardioplegia solutions after cardiac arrest. Control rat hearts (n=6) were immersed in University of Wisconsin (UW) solution whereas AFGP-treated hearts (AFGP group) (n=6) were immersed in UW solution containing 500 ?g/ml AFGP. After static hypothermic preservation, a Langendorff apparatus was used to reperfuse the coronary arteries with oxygenated Krebs-Henseleit solution. After 30, 60, 90, and 120 min, the heart rate (HR), coronary flow (CF), cardiac contractile force (max dP/dt), and cardiac diastolic force (min dP/dt) were measured. Tissue water content (TWC) and tissue adenosine triphosphate (ATP) levels in the reperfused preserved hearts were also assessed. All the parameters were compared between the control and AFGP groups. Compared with the control group, the AFGP group had significantly (p<0.05) higher values of the following parameters: HR at 60, 90, and 120 min; CF at all four time points; max dP/dt at 90 min; min dP/dt at 90 and 120 min; and tissue ATP levels at 120 min. TWC did not differ significantly between the groups. The higher HR, CF, max dP/dt, min dP/dt, and tissue ATP levels in the AFGP compared with those in control hearts suggested that AFGP conferred superior hemodynamic and metabolic functions. Thus, AFGP might be a useful additive for the static/nonfreezing hypothermic preservation of hearts.

Does pediatric heart transplant survival differwith variouscardiac preservation solutions?

Few studies directly compare outcomes between the most commonly used preservation solutions in pediatric heart transplantation in a large cohort of recipients. The purpose of this study is to investigate the effect of cardiac preservation solution on survival in pediatric heart transplant recipients. The United Network for Organ Sharing (UNOS) database was retrospectively reviewed from 01/2004-03/2018 for pediatric donor hearts. Saline, University of Wisconsin (UW), "cardioplegia," Celsior, and Custodiol preservation solutions were evaluated. The primary endpoints wererecipient survival at 30days, 1year, and long term. Afterexclusion criteria, 3012 recipients had preservation solution data available. The most common preservation solution used was UW in 1203 patients (40%), followed by Celsior in 542 (18%), cardioplegia in 461 (15%), saline in 408 (14%), and Custodiol in 398 (13%). Survival of recipients whose donor hearts were procured with UW was as follows: 97%-30day, 92%-1year; Celsior: 97%-30day, 92%-1year; cardioplegia: 97%-30day, 91%-1year; saline: 97%-30day, 91%-1year; and Custodiol: 96%-30day and 92%-1year. Analysis of Cox models for 30-day and long-term survival revealed no statistical differences when comparing UW to Celsior (p=.333), cardioplegia (p=.914), saline (p=.980), or Custodiol (p=.642) in adjusted models. There were no significant differences in 30-day or 1-year survival detected between commonly used preservation solutions in the pediatric heart transplant population.

DelNido cardioplegia versus St Thomas cardioplegia solution in double valve replacement: a single centre experience.

The role of cardioplegia cannot be underrated in cardiac surgery. St Thomas solution is the most widely used cardioplegic, but needs repeated dosing. Del Nido solution provides long duration of asystole with adequate protection; but has been used mainly in paediatric patients. This study was aimed to compare Del Nido cardioplegia with St Thomas cardioplegia in adult cardiac surgeries, requiring double valve replacement and compare the outcomes. This retrospective, observational, descriptive study was conducted over a time period spanning from January 2016 to December 2019. A total of 209 patients were included and were separated in two groups DC group (n = 114) and BC group (n = 95) on the basis of cardioplegic solution used. Del Nido solution was administered as single dose. Parameters noted were CPB time, cross clamp time, wean off bypass time, DC shocks given, inotropic support required, ventilation duration, duration of ICU and hospital stay. There was significantly shorter aortic cross clamp time (72.6 ± 10.2 vs. 98.2 ± 9.2), CPB time (92.1 ± 12.3 vs.129.5 ± 11) and wean off bypass time (19.4 ± 5.9 vs. 31.3 ± 7.6) and less requirement of DC shocks (21.2% vs. 65.9%) in DC group. Inotropic requirement in immediate post-operative period was significantly less in DC group both on day of surgery (5.35 ± 1.44 vs. 7.52 ± 3.8) and 24 hours later (3.4 ± 2.12 vs. 2.18 ± 0.72). There was no significant difference in duration of ventilation, ICU and hospital stay. Del Nido can be used safely in long duration adult cardiac surgeries and in a single dose with better intra operative and immediate post-operative outcomes as compared to St Thomas solution.

St. Thomas and del Nido cardioplegia are superior to Custodiol cardioplegia in a rat model of donor heart

Objectives Cardiac transplantation is an effective treatment for advanced heart disease and protection of the donor organ is directly associated with post-transplantation outcomes. Cardioplegic strategies intend to protect the donor heart against ischemic injury during transplantation procedures. In our study, the effects of three different cardioplegia solutions were evaluated in a rat heart donor model in terms of cellular base. Design. Cardioplegia solutions as St. Thomas, del Nido or Custodiol were administered to male Wistar albino rats until cardiac arrest. Arrested hearts were excised and incubated in cold cardioplegia solutions for 4 h. Organ bath experiments were performed using the right ventricular free wall strips of the heart tissues. ATP, sialic acid, TNF-α levels and MMP-9 activities were measured in heart tissues. Incubation media were also used to measure TNF-α and troponin-I levels following organ baths experiments. Results. Custodiol administration led to reduced myocardial contraction (p < .05), decreased ATP levels (p < .001) and increased both TNF-α levels (p < .05), and MMP-9 activity (p < .05). Additionally, troponin-I and TNF-α levels in media were significantly increased (p < .05), TNF-α levels were positively correlated with MMP-9 activities (r = .93, p = .007) and negatively correlated with ATP levels (r = −.91, p = .01) in the Custodiol group. Also, MMP-9 activities were negatively correlated with ATP levels (r = −.90, p = .01) Conclusion. Custodiol cardioplegia cannot prevent functional and cellular damage in donor heart tissue. St. Thomas or del Nido cardioplegia could result in superior functional and biochemical improvement during transplantation procedures. In this respect, these cardioplegic solutions may be more advantageous as cellular and functional.

COMPARISON STUDY: INTERMITTENT ANTIGRADE WARM CARDIOPLEGIA VERSUS ANTIGRADE COLD INTERMITTENT BLOOD CARDIOPLEGIA FOR MYOCARDIAL PROTECTION DURING ELECTIVE ON PUMP CORONARY ARTERY BYPASS GRAFTING IN EARLY POST-OPERATIVE PERIOD

Background: Defending the heart against potential damage during cross-clamping is the most important and vital step to ensuring a successful surgical outcome(1). The creation of cardioplegia solutions was one of the major advances in cardiac surgery that allowed surgeons to conduct complicated surgical procedures to avoid myocardial injury (14). Treating cardioplegia at a cool temperature would be a significant factor in lowering myocardial metabolism. However, the reduction in myocardial metabolism due to hypothermia, compared with that achieved by diastolic arrest, is usually very negligible. Since Normothermias enzymatic and cellular processes work better (7). Owing to the propensity of the heart to resume electrical operation during normothermia, however, this must be administered consistently or only with short interruptions (4). Terminal warm blood cardioplegia (hot shot) is normally done just before the elimination of the aortic cross-clamp since it has been demonstrated that myocardial metabolism is increasing (23). Methods: A prospective controlled randomised study (200 hundred patients aged 40 to 65 years of both sexes underwent elective CABG pump surgery) will be included. They will be divided into three groups of patients: Group I:includes 100 Patients who received intermittent cold blood cardioplegia. Group II:includes 100 Patients who received intermittent warm blood cardioplegia with controlled reperfusion for 3 minutes before aortic unclamping. Study made from January, 2019 to August, 2020, at National Heart Institute.All patients were thoroughly evaluated preoperatively, intraoperatively, and postoperatively. Results: We hypothesized that in our patient cohort, warm blood cardioplegia could be as successful as or even better than the conventional antegrade cold blood cardioplegia. Patients were randomised into two similar blocks, each of which consisted of 100 patients, each of whom obtained one of the two cardioplegic solutions. Our analysis did not indicate a statistically important difference in the post-operative release of myocardial biomarkers (Troponin I) &amp; CK in both classes. This finding did not significantly reflect the clinical outcome of our patient, which may indicate similar myocardial protection in primary low-risk CABG patients for both cold and warm blood cardioplegia. Conclusion: During the time of cardiac arrest, both methods tend to enable an equal and adequate approach for myocardial defence. To attain improved myocardial defence, warm blood cardioplegia needs a shorter administration interval. Therefore, the choice between one type of cardioplegia and the other remains at the discretion of the surgeon. The statistically minor variation found in the release of myocardial enzymes did not translate into distinct clinical results.

Assessment of the right ventricle in donation after circulatory death hearts

In donation after circulatory death heart transplantation, the donor heart is exposed to circulatory load. The right ventricle, due to its structure, has high compliance for volume load but is particularly vulnerable to increased pressure load. This study used a porcine model to conduct a functional assessment of the hemodynamics of the heart, with a focus on the right ventricle. Six pigs weighing 24.6±1.4kg were used. Circulatory death was induced by asphyxiation after median sternotomy. After 30minutes in the state of global warm ischemia, the ascending aorta was clamped, followed by a 20-minute reperfusion of the heart with a 20°C blood cardioplegia solution. Systemic circulation was established by cardiopulmonary bypass after aortic cross-clamping. After initial reperfusion, the blood cardioplegia solution was replaced with blood. The blood was then rewarmed while the heart was still in a non-working state. Cardiac function was assessed twice in situ, first by the thermodilution method, and then, by the pressure-volume measurement both at preischemia and at three hours after initiation of reperfusion. The recovery rate of cardiac output was 75%. End-systolic elastance (P=.02) and pulmonary arterial elastance significantly increased (P=.03), but the ratio of arterial elastance to end-systolic elastance was preserved (P=.91) in the right ventricle. Despite a decrease in cardiac output after reperfusion from warm ischemia, the right ventricle had a potential to respond the elevated afterload. It is important that donations after circulatory death heart transplantation should be performed with attention to avoiding right ventricular distension.

The Effect of Supplemental Cardioplegia Infusion before Anastomosis in Patients Undergoing Heart Transplantation with Long Ischemic Times.

BackgroundProlonged ischemic time is a risk factor for primary graft dysfunction in patients who undergo heart transplantation. We investigated the effect of a supplemental cardioplegia infusion before anastomosis in patients with long ischemic times.MethodsWe identified 236 consecutive patients who underwent orthotopic heart transplantation between February 2010 and December 2014. Among them, the patients with total ischemic times of longer than 3 hours (n=59) were categorized based on whether they were administered a complementary cardioplegia solution (CPS) immediately before implantation (CPS+, n=30; CPS−, n=29).ResultsThe mean total ischemic times in the CPS+ and CPS− groups were 238.1±30.1 minutes and 230.1±28.2 minutes, respectively (p=0.3). The incidence of left ventricular primary graft dysfunction (CPS+, n=6 [20.0%]; CPS−, n=5 [17.2%]; p=0.79) was comparable between the groups. In the Kaplan-Meier survival analysis, no significant difference in overall survival at 5 years was observed between the CPS+ and CPS− groups (83.1%±6.9% vs. 89.7%±5.7%, respectively; log-rank p=0.7). No inter-group differences in early mortality (CPS+, n=0; CPS−, n=1 [3.4%]; p=0.98) or complications were observed.ConclusionThe additional infusion of a cardioplegia solution immediately before implantation in patients with longer ischemic times is a simple, reproducible, and safe procedure. However, we did not observe benefits of this strategy in the present study.

Myocardial Protection by Blood-Based Del Nido versus St. Thomas Cardioplegia in Cardiac Surgery for Adults and Children.

St. Thomas (ST) and Del Nido (DN) cardioplegic solutions are widely used for myocardial protection during cardiac surgery. In 2016, our university hospital shifted from modified St. Thomas to Del Nido solution for both adult and pediatric cardiac surgery. This retrospective study was conducted to compare ST and DN solutions regarding surgical workflow and clinical outcome in pediatric and adult patients undergoing cardiac surgery. We reviewed 220 patients who underwent cardiac surgery requiring cardioplegic arrest. Patients were categorized in 2 groups: ST (n = 110) and DN (n = 110). Each group included 60 pediatric and 50 adult patients. Demographic, intraoperative, and postoperative variables were collected. In pediatric patients, no significant difference was found between the 2 groups regarding clamping time, bypass time, need for defibrillation, inotropic score, postoperative ejection fraction (EF), period of mechanical ventilation, intensive care unit stay, or postoperative arrhythmias. One patient in the ST group required mechanical support by extracorporeal membrane oxygenation. We had 5 cases of pediatric mortality (3 in DN and 2 in ST, P = .64). In adult patients, significantly fewer patients in the DN group needed defibrillation than in the ST group. No significant difference was found regarding clamping time, inotropic score, or intraaortic balloon pump use. Mortality in adult patients was 6 cases (4 in ST group and 2 in DN group). DN cardioplegia solution is as safe as ST solution in pediatric and adult cardiac surgery. It has comparable results of myocardial protection and clinical outcome, with superiority regarding uninterrupted surgery and lower rate of defibrillation.

Cardioplegia heat exchangers thermal properties

Cardiac surgeries that involve cardiopulmonary bypass technique require a stable temperature maintenance for oxygenated blood or the cardioplegia solution. For this purpose, the heat exchangers are used. Nowadays, these exchangers consist of stainless steel tubes or bellows in a plastic shell. The blood is then warmed or cooled by water flowing in the shell around these structures. In the paper, the thermal specifications of two commercially used cardioplegia heat exchangers Capiox Cardioplegia and MYOtherm XP were evaluated and compared. For this purpose, a water was used as a substitution for blood. Both components were tested for varying flow rates in the pipes in the range 20-150 l/h and fixed flow rate 700 l/h in the shell. The thermal performances of both devices resulted similarly (up to 2.4 kW) at maximal flow rate. The performance factors for low flow rates approached values close to 0.98 and with increasing flow rate decreased down to 0.50. MYOtherm XP shows lower pressure drop than Capiox Cardioplegia due to more optimal construction. The major difference between the heat exchangers was observed in overall heat transfer coefficients at maximal flow rate and resulted in 2191.3 W/m2K or 1760.2 W/m2K for MYOtherm XP or Capiox Cardioplegia, respectively.

An acute estrogen receptor agonist enhances protective effects of cardioplegia in hearts from aging male and female mice.

The G-protein coupled estrogen receptor (GPER) mediates rapid responses to estrogen. GPER activation may contribute to cardioprotective effects of estrogen in ischemia and reperfusion, although whether it is beneficial in aging myocardium is unclear. We determined whether a GPER agonist (G1) added to standard cardioplegic solution (used to protect hearts from ischemia-reperfusion injury during cardiac surgery) would improve outcomes in isolated hearts from adult and aged mice of both sexes. Hearts from young adult (6-9 mos) and older (22-28 mos) mice were perfused with Krebs-Henseleit buffer for 15min (37°C) followed by cold (6-7°C) St. Thomas'2 cardioplegia with G1 (0.5μM), G1 (0.5μM) plus G15 (GPER antagonist; 1μM) or vehicle for 6min. Hearts were then subjected to global ischemia (90min; 23-24°C) and reperfusion (30min; 37°C). Infarct size was quantified with triphenyltetrazolium chloride. In adult females, left ventricular developed pressure (LVDP) recovered to only 45.1±11.9% of baseline in control hearts in reperfusion, but recovered to 76.5±3.9% with G1 treatment (p<0.05) and this was blocked by G15. Similar results were obtained in older males and females (LVDP=51.5±10.6% vs. 84.8±8.7% and 51.9±5.5% vs. 90.0±6.1% for older males and females, respectively; p<0.05). By contrast, G1 had no effect on recovery of LVDP in hearts from adult males (26.6±8.9% vs. 46.0±14.2%). The rates of pressure development and decay showed a similar pattern of recovery in reperfusion. Infarcts were significantly smaller in G1-treated hearts from all older mice and in younger females, although G1 had no impact on infarct size in adult males (48.1±7.7% for control vs. 32.6±8.0% for G1). G1 enhances cardioprotective properties of a standard cardioplegic solution in the aging myocardium of both sexes. Supplementation of cardioplegic solutions with GPER agonists is a potential translational intervention that may improve cardiac surgery outcomes in older adults.

A proposed redosing interval of del Nido cardioplegia solution in adult cardiac surgery: a propensity-matched study.

Recently, del Nido cardioplegia solution (DN) has been utilized in adult cardiac surgery. However, adequate interval of maintenance dose(s) is still unclear. The purpose of this study was to assess the safety and efficacy of our DN protocol by comparing with conventional cold whole blood cardioplegia (CWB). A total of 1003 consecutive patients (DN group, N = 350 vs. CWB group, N = 653) underwent cardiovascular surgery between July 2013 and September 2018 were included in this study. The DN protocol was to administer 1000 to 1200 ml as an initial dose and to add maintenance dose(s) (500 ml each) every 60 minutes when the estimated cross-clamp time was over 90 minutes. CWB was given every 20 minutes, regardless of cross-clamp time. Propensity matching identified 254 matched pairs for analysis. The preoperative and postoperative data were reviewed. Cross-clamp time was significantly shorter in the DN group compared with the CWB group (107 ± 56 minutes vs. 116 ± 49 minutes, p = 0.0458). A retrograde cannula was used in 124 (48.8%) patients in the DN group and 181 (71.3%) patients in the CWB group (p < 0.0001). There were no significant differences in requiring postoperative cardiac supports (inotropes, mechanical circulatory supports) and major complications. In-hospital mortality was similar between two groups (DN group: 3.2% vs. CWB group: 2.4%, p = 0.5872). Short-term clinical outcomes in the patients underwent cardiovascular surgery with the DN protocol including the redosing interval strategy were acceptable. Also, DN protocol was associated with shortened cross-clamp time and less usage of the retrograde cannula.

Specific parameters of operation of the minimized system for cardioplegia in children. Bench test

It is very important to observe all the parameters of cardioplegia when protecting myocardium during cardiac surgery. To perform this task, it is necessary to have clear understanding of properties of the elements of the extracorporeal circuit of cardiopulmonary bypass. The objective : to develop a test model and using it to evaluate technical capabilities of blood cardioplegic system reducing the filling volume of the heat exchange chamber and the system supplying solution to the myocardium. Subjects and methods . A model of a neonatal cardiopulmonary bypass circuit was tested, it included an oxygenator and the cardioplegic system with a 7-ml heat exchange chamber; changes in the pressure and temperature in key nodes of the extracorporeal and cardioplegic circuits were assessed when the pump velocity, ambient temperature and fluid temperature in the main circuit were changed. Results . This modification provides a wide range of liquid volumetric velocities. Maintaining the selected variant of blood cardioplegia and safe pressure within the cardioplegic circuit is ensured at the perfusion rate of up to 350 ml/min. With normothermal circulation and air temperature in the operating room of 23°C, parameters of the cardioplegic circuit and solution delivery system allows maintaining the solution temperature within the range from 16 to 19°C. When the solution is cooled in a heat exchanger down to 4°C, the temperature of the final cardioplegic solution is maintained within 12-17°C; and with normothermal perfusion, air temperature in the operating room of 15°C and the solution temperature in the heat exchange chamber of 4°C, the temperature of the final cardioplegic solution can be within 6‒13°C. With perfusion in the mode of moderate hypothermia (32°C), air temperature in the operating room 15°C and temperature in the heat exchange chamber 4°C, the final cardioplegic solution can be delivered at the temperature from 5 to 9°C. Conclusions . The proposed test model allows investigating aimed to find out additional characteristics of the cardioplegic circuit. Ambient air temperature, cardioplegic pump velocity and main circuit fluid temperature are the main factors influencing the final cardioplegic solution temperature. When using the studied variant of the cardioplegic circuit assembly, the maintenance of the selected variant of blood cardioplegia and safe pressure inside the cardioplegic circuit are ensured at a perfusion rate of up to 350 ml/min.