The Potential Neurological Impact of Intraoperative Hyponatremia Using Histidine-Tryptophan-Ketoglutarate Cardioplegia Infusion in Adult Cardiac Surgery.

Background and Objectives: The relationship between histidine-tryptophan-ketoglutarate (HTK)-induced hyponatremia and brain injury in adult cardiac surgery patients is unclear. This study analyzed postoperative neurological outcomes after intraoperative HTK cardioplegia infusion. Materials and Methods: A prospective cohort study was conducted on 60 adult patients who underwent cardiac surgery with cardiopulmonary bypass. Of these patients, 13 and 47 received HTK infusion and conventional hyperkalemic cardioplegia, respectively. The patients' baseline characteristics, intraoperative data, brain injury markers, Mini-Mental State Examination (MMSE) scores, and quantitative electroencephalography (qEEG) data were collected. Electrolyte changes during cardiopulmonary bypass, the degree of hyponatremia, and any associated brain insults were evaluated. Results: The HTK group presented with acute hyponatremia during cardiopulmonary bypass, which was intraoperatively corrected through ultrafiltration and normal saline administration. Postoperative sodium levels were higher in the HTK group than in the conventional cardioplegia group. The change in neuron-specific enolase levels after cardiopulmonary bypass was significantly higher in the HTK group (p = 0.043). The changes showed no significant differences using case-control matching. qEEG analysis revealed a significant increase in relative delta power in the HTK group on postoperative day (POD) 7 (p = 0.018); however, no significant changes were noted on POD 60. The MMSE scores were not significantly different between the two groups on POD 7 and POD 60. Conclusions: HTK-induced acute hyponatremia and rapid correction with normal saline during adult cardiac surgeries were associated with a potential short-term but not long-term neurological impact. Further studies are required to determine the necessity of correction for HTK-induced hyponatremia.

Cardioplegia Application with A Hand-Squeezed Cardioplegia Bag. Is It Safe?

OBJECTIVES: Cardioplegia solutions have a role not only in arresting the heart but also in protecting the myocardium from ischemia. While antegrade cardioplegia is given by the heart-lung machine in many centers, it is given by a hand-squeezed bag in very few centers. The pressure of cardioplegia given antegrade from the heart-lung machine is certain (60-90 mmHg). The pressure applied in the cardioplegia method, which is given antegrade with a hand-squeezed bag, is uncertain and variable. We compared the antegrade cardioplegia method applied with a hand-squeezed bag with the antegrade cardioplegia method applied with a roller pump from the heart-lung machine in terms of protecting the myocardium from ischemia. METHODS: Seventy-six patients who did not have an acute myocardial infarction, had normal preoperative cardiac marker (troponin and CK-MB) values, did not undergo redo open heart surgery, had an ejection fraction of 50% and above, and underwent elective two or three-vessel isolated coronary artery bypass surgery were evaluated. While tepid (30-32°C) blood cardioplegia was administered antegrade to 33 patients (Group A) with a hand-squeezed bag, the other 34 patients (Group B) received tepid (30-32°C) antegrade blood cardioplegia from the heart-lung machine. The perioperative and postoperative data of the patients were recorded and compared. To evaluate myocardial damage, postoperative cardiac markers and echocardiography data were evaluated and compared at the fourth hour after the cross-clamp was removed in both groups. RESULTS: When evaluated in terms of preoperative demographic data, preoperative mean EF values and intraoperative data, there was no statistical difference between both groups. When we evaluated in terms of myocardial protection, the mean TnT level was 4.31 ± 1.95 at the 4th hour in Group A and 3.91 ± 1.69 in Group B. Mean 4th hour CK-MB level was 40.84 ± 9.07 in Group A and 38.56 ± 8.07 in Group B. Mean change in EF (%) was -4.09 ± 4.41 in Group A and 3.53 ± 4.53 in Group B. In line with the current data when we evaluated in terms of myocardial protection, we found that there is no statistical difference between the two groups (P = 0.373; P = 0.158; P = 0.523). There was no statistical difference between both groups, in terms of postoperative arrhythmias. None of the patients died, and no patients required an intra-aortic balloon pump. RESULTS: As a result of our study, cardioplegia administration with a certain constant pressure from the roller pump and hand-squeezed bag with uncertain pressure does not make a difference, in terms of myocardial protection. We think that the content and amount of cardioplegia and the preferred time for repeated cardioplegia applications are more important for the protection of the myocardium. METHODS: 76 patients who did not have an acute myocardial infarction, had normal preoperative cardiac marker (troponin and CK-MB) values, did not undergo redo open heart surgery, had an ejection fraction of 50% and above, and underwent elective two or three-vessel isolated coronary artery bypass surgery were evaluated. While tepid(30-32 ° C) blood cardioplegia was administered antegrade to 33 patients(Group A) with a hand-squeezed bag, the other 34 patients(Group B) received tepid(30-32 °C) antegrade blood cardioplegia from the heart-lung machine. The perioperative and postoperative data of the patients were recorded and compared. To evaluate myocardial damage, postoperative cardiac markers and echocardiography data were evaluated and compared at the fourth hour after the cross-clamp was removed in both groups. RESULTS: When evaluated in terms of preoperative demographic data, preoperative mean EF values and intraoperative data there was no statistical difference between both groups. When we evaluated in terms of myocardial protection, the mean TnT level was 4.31 ± 1.95 at the 4th hour in group A and 3.91 ± 1.69 in group B. Mean 4th hour CK-MB level was 40.84 ± 9.07 in group A and 38.56 ± 8.07 in group B. Mean change in EF (%) was -4.09 ± 4.41 in group A and 3.53 ± 4.53 in group B. In line with the current data when we evaluated in terms of myocardial protection; we found that there is no statistical difference between the two groups (p = 0.373; p = 0.158; p = 0.523). There was no statistical difference between both groups in terms of postoperative arrhythmia's. None of the patients died and none of the patients required an intra-aortic balloon pump.

Transitioning to Del Nido cardioplegia for all-comers: the next switching gear?

BACKGROUND: Exclusive use of Del Nido cardioplegia administration in all adult patients undergoing cardiac surgery has been studied for operative, postoperative and myocardial protection outcomes. METHODS: From November 2016 to October 2017, Del Nido cardioplegia was used in 131 consecutive patients (DN group). Using a propensity score, DN group was compared to 251 patients having received intermittent cold blood cardioplegia (CB group). RESULTS: Preoperative characteristics were similar in DN and CB groups. Operative outcomes were statistically different (p < 0.0001): cardiopulmonary bypass (CPB) time (DN 105.9 ± 46.5, CB 131.2 ± 38.8); aortic cross-clamp time (DN 80.8 ± 35.5, CB 102.2 ± 31.3); operative time (DN 203.1 ± 65.0, CB 241.5 ± 54.7); total cardioplegia volume (DN 1328 ± 879, CB 3773 ± 1226); and peak glycemia on CPB (DN 8.2 ± 2.3, CB 9.0 ± 1.8). No statistical differences were noted in intensive care unit stay, hospital stay and hospital death. Myocardial protection outcomes were similar: discharge left ventricular ejection fraction (DN 52 ± 11, CB 51 ± 10); Troponin levels at the end of the surgery (DN 871 ± 1623, CB 1958 ± 854), day 1 (DN 853 ± 1139, CB 993 ± 8234) and day 4 (DN 442 ± 540, CB 463 ± 317). CONCLUSION: Del Nido cardioplegia use in all adult cardiac surgeries is associated with improved surgical efficiency. The design of larger trials including adults combined cardiac procedures and emergencies is needed.

Microplegia versus Cardioplexol® in Coronary Artery Bypass Surgery with Minimal Extracorporeal Circulation: Comparison of Two Cardioplegia Concepts.

BACKGROUND: The aim of this study is to compare the combined use of the Myocardial Protection System and our microplegia (Basel Microplegia Protocol) with Cardioplexol® in coronary artery bypass grafting using the minimal extracorporeal circulation. METHODS: The analysis focused on propensity score matched pairs of patients in whom microplegia or Cardioplexol® was used. Primary efficacy endpoints were high-sensitivity cardiac troponin-T on postoperative day 1 and peak values during hospitalization. Furthermore, we assessed creatine kinase and creatinine kinase-myocardial type, as well as safety endpoints. RESULTS: A total of 56 patients who received microplegia and 155 patients who received Cardioplexol® were included. The use of the microplegia was associated with significantly lower geometric mean (confidence interval) peak values of high-sensitivity cardiac troponin-T (233 ng/L [194-280 ng/L] vs. 362 ng/L [315-416 ng/L]; p = 0.001), creatinine kinase (539 U/L [458-633 U/L] vs. 719 U/L [645-801 U/L]; p = 0.011), and creatinine kinase-myocardial type (13.8 µg/L [9.6-19.9 µg/L] vs. 21.6 µg/L [18.9-24.6 µg/L]; p = 0.026), and a shorter length of stay on the intensive care unit (1.5 days [1.2-1.8 days] vs. 1.9 days [1.7-2.1 days]; p = 0.011). Major adverse cardiac and cerebrovascular events occurred with roughly equal frequency (1.8 vs. 5.2%; p = 0.331). CONCLUSIONS: The use of the Basel Microplegia Protocol was associated with lower peak values of high-sensitivity cardiac troponin-T, creatinine kinase, and creatinine kinase-myocardial type and with a shorter length of stay on the intensive care unit, as compared with the use of Cardioplexol® in isolated coronary artery bypass surgery using minimal extracorporeal circulation.

Microplegia in cardiac surgery: Systematic review and meta-analysis.

BACKGROUND: Consensus on the optimum choice of cardioplegia remains elusive. One possibility that has been suggested to have beneficial properties is microplegia, a cardioplegia of reduced crystalloid volume. The aim of this meta-analysis is to comprehensively investigate microplegia against a range of clinical outcomes. METHODS: To identify potential studies, systematic searches were carried out in four databases (eg, Pubmed, EMBASE). The search strategy included the key concepts of "microplegia" OR "mini-cardioplegia" OR "miniplegia" AND "cardiac surgery." This was followed by a meta-analysis investigating: mortality, crystalloid volume; cardiopulmonary bypass time; cross-clamp time; intra-aortic balloon pump use; spontaneous heartbeat recovery; inotropic support; low cardiac output syndrome; myocardial infarction; acute renal failure; atrial fibrillation, reoperation for bleeding; creatine kinase myocardial band (CK-MB); intensive care unit (ICU) time and hospital stay. RESULTS: Eleven studies comprising 5798 participants were analyzed. Microplegia used a lower volume of crystalloids and led to a higher spontaneous return of heartbeat, odds ratio (OR) 4.271 (95% confidence intervals [CIs]: 1.935, 9.423; I2 = 76.57%; P < .001) and a lower requirement for inotropic support, OR: 0.665 (95% CI: 0.47, 0.941; I2 = 3.53%; P = .021). Microplegia was also associated with a lower CK-MB release, mean difference (MD) -6.448 ng/mL (95% CI: -9.386, -3.511; I2 = 0%; P < .001) and a shorter ICU stay, MD: -0.411 days (95% CI: -0.812, -0.009; I2 = 17.65%; P = .045). All other comparisons were nonsignificant. CONCLUSIONS: Microplegia has similar effects to other types of cardioplegia and is beneficial with regard to spontaneous return of heartbeat, inotropic support, ICU stay, and CK-MB release.

The Use of del Nido Cardioplegia for Myocardial Protection in Isolated Coronary Artery Bypass Surgery.

BACKGROUND: The del Nido (DN) cardioplegia solution has been widely used in paediatric open-heart surgery for years; however, its application in adult open-heart surgery has not yet gained sufficient popularity. We investigated the safety and efficiency of the DN cardioplegia solution versus the traditional crystalloid cardioplegia solution [St. Thomas' Hospital (STH) cardioplegia solution] in adult patients undergoing coronary artery bypass grafting (CABG). METHODS: A retrospective comparative analysis of 200 consecutive patients undergoing isolated on-pump CABG between April 2016 and September 2017 was performed. Patients were divided into two groups: DN group (n = 100) and STH group (n = 100). Groups were compared with regard to perioperative clinical outcomes, and the safety and efficiency of the DN cardioplegia solution in CABG surgery were evaluated. RESULTS: In the DN group, mean aortic cross-clamp, cardiopulmonary bypass, and total operation times were significantly shorter than in the STH group. After the release of the aortic cross-clamp, the requirement for intraoperative defibrillation was significantly less in the DN group. There were no significant differences between the groups in terms of the levels of perioperative cardiac biomarkers (including creatine kinase-myocardial band and troponin I), major postoperative adverse events, and in-hospital mortality. CONCLUSIONS: This study revealed that the use of the DN cardioplegia solution in adult patients undergoing isolated CABG provides significantly shorter aortic cross-clamp, cardiopulmonary bypass, and total operation times compared with the traditional cardioplegias solution. The DN solution could be used as a safe and efficient alternative to the traditional cardioplegia solutions in CABG surgery.

Impact of Crystalloid or Albumin Priming of the Heart-Lung Machine on Inhospital Outcome after Coronary Artery Bypass Surgery.

BACKGROUND: Crystalloid priming is a cost-effective, free from immunological reactions, and independent from human plasma delivery. However, there is some debate on the negative impact of low plasma colloid pressure and higher incidence of systemic inflammatory response syndrome (SIRS). The aim of the study was to rule out any adverse effects of crystalloid priming on the postoperative outcome. METHODS: We investigated 520 consecutive patients, including emergencies, who had isolated on-pump coronary artery bypass grafting in 2009 by retrospective analysis in our clinic. Crystalloid priming (n = 294) was introduced as an alternative to albumin (n = 226). Reviewing patient charts and IT-based data generated a dataset of perioperative parameters. RESULTS: There were no differences with respect to demographical data and preexisting comorbidities between both groups. Despite equal perfusion times, more volume had to be substituted during extracorporeal circulation following crystalloid priming. However, this did not influence the inhospital outcomes. According to the definition of the "Sepsis-3 Guidelines," the incidence of SIRS was similar. There was no difference in the need for a vasopressor treatment, and only transient higher serum lactate levels were found in the crystalloid group. The incidence of neurologic and organ-related adverse events, as well as 30-day mortality was comparable. CONCLUSION: The use of crystalloid priming is safe in coronary artery bypass grafting surgery in adults. However, there might be a greater need for crystalloid fluids during surgery.

Low-Volume Cardioplegia and Myocardial Protection in Coronary Artery Bypass Graft Surgery.

We studied myocardial protection during coronary artery bypass graft surgery using low-volume cardioplegia (Cardioplexol) and minimal extracorporeal circulation (MECC) for different types of coronary artery diseases. In total, 426 consecutive patients were included and divided into four groups: those with left main stem stenosis (n = 45), those with three-vessel disease (n = 200), those with both (n = 141), and those with neither (n = 40). The peak postoperative myocardial markers and 30-day mortality were analyzed. Both myocardial markers and 30-day mortality were significantly elevated in patients with isolated main stem stenosis. We conclude that the use of low-volume cardioplegia and MECC is safe. However, patients with underlying isolated left main stem stenosis might be less protected.

Myocardial Protection in Minimally Invasive Mitral Valve Surgery: Retrograde Cardioplegia Alone Using Endovascular Coronary Sinus Catheter Compared With Combined Antegrade and Retrograde Cardioplegia.

OBJECTIVE: To compare myocardial protection with retrograde cardioplegia alone with antegrade and retrograde cardioplegia in minimally invasive mitral valve surgery (MIMS). DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: The authors studied 97 MIMS patients using retrograde cardioplegia alone and 118 MIMS patients using antegrade and retrograde cardioplegia. INTERVENTIONS: The data from patients admitted for MIMS using retrograde cardioplegia (MIMS retro) between 2009 to 2012 were compared with the data from patients undergoing MIMS with antegrade and retrograde cardioplegia (MIMS ante-retro) between 2006 and 2010 (control group). Cardioplegia in the MIMS retro group was delivered solely through an endovascular coronary sinus (CS) catheter positioned under echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia was used in the MIMS ante-retro group. Data regarding myocardial infarction (MI; creatine kinase Mb, troponin T, electrocardiogram), myocardial function, and hemodynamic stability were collected for comparison. MEASUREMENTS AND MAIN RESULTS: Adequate cardioplegia administration (CS pressure >30 mmHg and asystole) was attained in 74.2% of the patients with retrograde cardioplegia alone. In 23.7% of the patients, the addition of an antegrade cardioplegia was necessary. No difference was observed in the incidence of MI (0 MIMS retro v 1 for MIMS ante-retro, p = 0.3623), difficult separation from cardiopulmonary bypass, and postoperative malignant arrhythmia. No difference was found for maximal creatine kinase Mb (39.1 [28.0-49.1] v 37.9 [28.6-50.9]; p = 0.8299) and for maximal troponin T levels (0.39 [0.27-0.70] v 0.47 [0.32-0.79]; p = 0.1231) for MIMS retro and MIMS ante-retro, respectively. However, lactate levels in the MIMS retro group were significantly lower than in the MIMS ante-retro group (2.1 [1.4-3.05] v 2.4 [1.8-3.3], respectively; p = 0.0453). No difference was observed in duration of intensive care unit stay and death. MIMS retro patients had a shorter hospital stay (7.0 [6.0-8.0] v 8.0 [7.0-9.0] days; p = 0.0003). CONCLUSION: Retrograde cardioplegia administration alone provided comparable myocardial protection to antegrade and retrograde cardioplegia during MIMS, but was not sufficient to achieve asystole in one-fifth of patients.

Myocardial protection with complementary dose of modified Del Nido cardioplegia during heart transplantation.

Myocardial protection during heart transplantation is achieved by a first dose of heart preservation solution during donor heart harvesting, while there is no consensus about the management of complementary doses during implantation in the recipient. We describe a preliminary case series where modified Del Nido Cardioplegia was used as complementary dose at the time of donor heart implantation.

Myocardial protection and clinical outcomes in Tetralogy of Fallot patients undergoing intracardiac repair: a randomized study of two cardioplegic techniques.

BACKGROUND: Myocardial protection in Tetralogy of Fallot patients undergoing intracardiac repair is suboptimal due to hypertrophied right ventricle. Hypertrophied myocardium is more susceptible to poor myocardial preservation because of inadequate capillary density as compared to the myocytes. There is a capillary to myocyte ratio mismatch. But del Nido Cardioplegia owing to its less viscosity is able to get more evenly distributed under hypothermic cardiopulmonary bypass as opposed to blood Cardioplegia. We hypothesized that the del Nido Cardioplegia technique, would be beneficial in myocardial protection because of its composition and method of delivery, leading into better early and late clinical outcomes in patients undergoing Tetralogy of Fallot repair as compared to blood cardioplegia reconstituted using St Thomas Cardioplegia solution. The objective of the study was to identify a better technique of myocardial preservation in Tetralogy of Fallot patient. METHODS: In total, 56 Tetralogy of Fallot patients undergoing intracardiac repair under mild hypothermic cardiopulmonary bypass were randomly allocated to receive antegrade Cardioplegia with either standard blood Cardioplegia (Group I) or del Nido Cardioplegia (Group II). Preoperative as well as postoperative data including echocardiographic parameters for right ventricle functions, creatine kinase MB level, inotropic requirement, mechanical ventilation duration, intensive care unit stay and hospital mortality were evaluated. RESULTS: Inotropic score in the first 24 hours postoperatively was significantly lower in Group II compared to Group I (13.4 ± 7.2 vs. 21.2 ± 9.6, p = 0.003). Creatine kinase MB level (ng/mL) was comparable between the groups. Echocardiographic parameters for right ventricle functions were also comparable between the groups during early as well as after 3 to 6 months postoperatively. CONCLUSION: Del Nido Cardioplegia is equally efficacious in providing myocardial protection during intracardiac repair under mild hypothermic cardiopulmonary bypass in Tetralogy of Fallot patients as compared to blood Cardioplegia solution with the added benefit of reducing inotropic requirement in first 24 hours postoperative period.

Myocardial Protection by Glucose-Insulin-Potassium in Moderate- to High-Risk Patients Undergoing Elective On-Pump Cardiac Surgery: A Randomized Controlled Trial.

BACKGROUND: Low cardiac output syndrome is a main cause of death after cardiac surgery. We sought to assess the impact of glucose-insulin-potassium (GIK) to enhance myocardial protection in moderate- to high-risk patients undergoing on-pump heart surgery. METHODS: A randomized controlled trial was performed in adult patients (Bernstein-Parsonnet score >7) scheduled for elective aortic valve replacement and/or coronary artery bypass surgery. Patients were randomized to GIK (20 IU of insulin, 10 mEq of potassium chloride in 50 mL of glucose 40%) or saline infusion given over 60 minutes on anesthetic induction. The primary end point was postcardiotomy ventricular dysfunction (PCVD), defined as new/worsening left ventricular dysfunction requiring inotropic support (≥120 minutes). Secondary end points were the intraoperative changes in left ventricular function as assessed by transoesophageal echocardiography, postoperative troponin levels, cardiovascular and respiratory complications, and intensive care unit and hospital length of stay. RESULTS: From 224 randomized patients, 222 were analyzed (112 and 110 in the placebo and GIK groups, respectively). GIK pretreatment was associated with a reduced occurrence of PCVD (risk ratio [RR], 0.41; 95% confidence interval [CI], 0.25-0.66). In GIK-treated patients, the left systolic ventricular function was better preserved after weaning from bypass, plasma troponin levels were lower on the first postoperative day (2.9 ng·mL(-) [interquartile range {IQR}, 1.5-6.6] vs 4.3 ng·mL(-) [IQR, 2.4-8.2]), and cardiovascular (RR, 0.69; 95% CI, 0.50-0.89) and respiratory complications (RR, 0.5; 95% CI, 0.38-0.74) were reduced, along with a shorter length of stay in intensive care unit (3 days [IQR, 2-4] vs 3.5 days [IQR, 2-7]) and in hospital (14 days [IQR, 11-18.5] vs 16 days [IQR, 12.5-23.5]), compared with placebo-treated patients. CONCLUSIONS: GIK pretreatment was shown to attenuate PCVD and to improve clinical outcome in moderate- to high-risk patients undergoing on-pump cardiac surgery.

Buckberg versus Calafiore Cardioplegia in Patients with Acute Coronary Syndromes.

BACKGROUND: Choice of cardioplegic solution plays a pivotal role in special subgroups of patients referred for on-pump cardiac surgery. This retrospective analysis aimed to assess the impact of intermittent warm (Calafiore, Cala) versus intermittent cold blood cardioplegia (Buckberg, Buck) in patients referred to coronary artery bypass graft (CABG) surgery due to acute coronary syndromes (ACS). METHODS: From 2008 to 2015, all consecutive patients undergoing urgent on-pump CABG surgery due to ACS (n = 950) were retrospectively analyzed. Intraoperative cardiac arrest was achieved using Buck (n = 273) or Cala (n = 677). Patients were compared regarding clinical outcomes and perioperative myocardial injury (PMI). Propensity score matching was performed to control for differences in preoperative patient characteristics. RESULTS: Prevalences of left main stenosis >50%, COPD, and advanced New York Heart Association (NYHA) class were higher for intermittent warm blood cardioplegia (IWC)-patients while more Buck-patients had preoperative intra-aortic balloon pump (IABP) and redo procedures. Buck-patients needed more intraoperative defibrillations and showed longer cardiopulmonary bypass (CPB) and aortic clamping times. 30-day all-cause mortality (10.6 versus 9.3%), major adverse cardiac events (MACE) (52.7 versus 48.6%), and PMI (50.5 versus 55.7%; all p > 0.05) rates were comparable for Buck- and Cala-patients. Propensity score matching resulted in equal group sizes (n = 212 each) and balanced distribution of preoperative covariates. Although more Buck-patients still needed inotropic support >24 hours postoperatively (25.7 versus 14.7%; p = 0.005) compared with Cala-group, outcome variables of interest did not differ between treatment groups (30-day mortality: 7.5 versus 9.0%; MACE: 49.5 versus 40.6%; PMI: 48.1 versus 37.3%; all p > 0.05). CONCLUSION: Buckberg and Calafiore cardioplegia offer comparable myocardial protection and similar postoperative results in patients undergoing CABG surgery due to ACS.

Bretschneider and del Nido solutions: Are they safe for coronary artery bypass grafting? If so, how should we use them?

A variety of cardioplegic solutions are being used widely today to arrest the heart during coronary artery bypass grafting (CABG) and other cardiac operations. To minimize interruptions during the surgery for intermittent dosing of the cardioplegia and to facilitate less invasive cardiac procedures, single-shot solutions, including Bretschneider and del Nido solutions, have been introduced. This review examines the evidence regarding the safety and efficacy of Bretschneider and del Nido cardioplegia during CABG. The findings support their use in routine low-risk CABG, but finds insufficient evidence to support their safety in high-risk surgeries.

The practicalities of establishing a porcine isolated heart model.

BACKGROUND: The isolated heart apparatus is over 100 years old, but remains a useful research tool today. While designs of many large animal systems have been described in the literature, trouble-shooting and refining such a model to yield a stable, workable system has not been previously described. This paper outlines the issues, in tabular form, that our group encountered in developing our own porcine isolated heart rig with the aim of assisting other workers in the field planning similar work. The paper also highlights some of the modern applications of the isolated heart apparatus. Methods Landrace pigs (50-80 kg) were used in a pilot project to develop the model. The model was then used in a study examining the effects of various cardioplegic solutions on function after reanimation of porcine hearts. During the two projects, non-protocol issues were documented as well as their solutions. These were aggregated in this paper. RESULTS: Issues faced by the group without explicit literature solutions included pig size selection, animal acclimatisation, porcine transoesophageal echocardiography, cannulation and phlebotomy for cross-clamping, cardioplegia delivery, heart suspension and rig tuning. CONCLUSION: Prior recognition of issues and possible solutions faced by workers establishing a porcine isolated heart system will speed progress towards a useable system for research. The isolated heart apparatus remains applicable in transplant, ischaemia reperfusion, heart failure and organ preservation research.

Common variants associated with changes in levels of circulating free fatty acids after administration of glucose-insulin-potassium (GIK) therapy in the IMMEDIATE trial.

Glucose-insulin-potassium (GIK) therapy may promote a shift from oxygen-wasteful free fatty acid (FFA) metabolism to glycolysis, potentially reducing myocardial damage during ischemia. Genetic variation associated with FFA response to GIK was investigated in an IMMEDIATE (Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency care) sub-study (n=117). In patients with confirmed acute coronary syndromes, associations between 132 634 variants and 12-h circulating FFA response were assessed. Between initial and 6-h measurements, three LINGO2 variants were associated with increased levels of total FFA (P-value for 2 degree of freedom test, P2df ⩽5.51 × 10-7). Lead LINGO2 single-nucleotide polymorphism, rs12003487, was nominally associated with reduced 30-day ejection fraction (P2df=0.03). Several LINGO2 signals were linked to alterations in epigenetic profile and gene expression levels. Between 6 and 12 h, rs7017336 nearest to IMPA1/FABP12 showed an association with decreased saturated FFAs (P2df=5.47 × 10-7). Nearest to DUSP26, rs7464104 was associated with a decrease in unsaturated FFAs (P2df=5.51 × 10-7). Genetic variation may modify FFA response to GIK, potentially conferring less beneficial outcomes.

Effect of 0.9% Saline or Plasma-Lyte 148 as Crystalloid Fluid Therapy in the Intensive Care Unit on Blood Product Use and Postoperative Bleeding After Cardiac Surgery.

OBJECTIVE: To evaluate the effect of Plasma-Lyte 148 (PL-148) compared with 0.9% saline (saline) on blood product use and postoperative bleeding in patients admitted to the intensive care unit (ICU) following cardiac surgery. DESIGN: A post hoc subgroup analysis conducted within a multicenter, double-blind, cluster-randomized, double-crossover study (study 1) and a prospective, single-center nested-cohort study (study 2). SETTING: Tertiary-care hospitals. PARTICIPANTS: Adults admitted to the ICU after cardiac surgery requiring crystalloid fluid therapy as part of the 0.9% saline vs. PL-148 for ICU fluid therapy (SPLIT) trial. INTERVENTIONS: Blinded saline or PL-148 for 4 alternating 7-week blocks. MEASUREMENTS AND MAIN RESULTS: 954 patients were included in study 1; 475 patients received PL-148, and 479 received saline. 128 of 475 patients (26.9%) in the PL-148 group received blood or a blood product compared with 94 of 479 patients (19.6%) in the saline group (OR [95% confidence interval], 1.51 [1.11-2.05]; p = 0.008). In study 2, 131 patients were allocated to PL-148 and 120 patients were allocated to saline. There were no differences between groups in chest drain output from the time of arrival in the ICU until 12 hours postoperatively (geometric mean, 566 mL for the PL-148 group v 547 mL in the saline group; p = 0.60). CONCLUSIONS: The findings did not support the hypothesis that using PL-148 for fluid therapy in ICU following cardiac surgery reduces transfusion requirements compared to saline. The significantly increased proportion of patients receiving blood or blood product with allocation to PL-148 compared to saline was unexpected and requires verification through further research.

Blood Versus Crystalloid Cardioplegia in Pediatric Cardiac Surgery: A Systematic Review and Meta-analysis.

The benefit of blood cardioplegia (BCP) compared to crystalloid cardioplegia (CCP) is still debatable. Our aim was to systematically review and synthesize all available evidence on the use of BCP and CCP to assess if any modality provides superior outcomes in pediatric cardiac surgery. A systematic literature search of the PubMed and Cochrane databases was performed with respect to the PRISMA statement (end-of-search date: January 30th, 2017). We extracted data on study design, demographics, cardioplegia regimens, and perioperative outcomes as well as relevant biochemical markers, namely cardiac troponin I (cTnI), lactate, and ATP levels at baseline, after reperfusion and postoperatively at 1, 4, 12, and 24 h as applicable. Data were appropriately pooled using random and mixed effects models. Our systematic review includes 56 studies reporting on a total of 7711 pediatric patients. A meta-analysis of the 10 eligible studies directly comparing BCP (n = 416) to CCP (n = 281) was also performed. There was no significant difference between the two groups with regard to cTnI and Lac at any measured time point, ATP levels after reperfusion, length of intensive care unit stay (WMD: -0.08, 95% CI -1.52 to 1.36), length of hospital stay (WMD: 0.13, 95% CI -0.85 to 1.12), and 30-day mortality (OR 1.11, 95% CI 0.43-2.88). Only cTnI levels at 4 h postoperatively were significantly lower with BCP (WMD: -1.62, 95% CI -2.07 to -1.18). Based on the available data, neither cardioplegia modality seems to be superior in terms of clinical outcomes, ischemia severity, and overall functional recovery.

Del Nido cardioplegia in low risk adults undergoing first time coronary artery bypass surgery.

OBJECTIVES: Single-dose del Nido cardioplegia has been used in the pediatric population for many years. Only a small amount of data exists about its use in adult cardiac surgery. We sought to compare the outcomes of all patients undergoing coronary artery bypass, using our 4:1 blood cardioplegia versus single-dose 1:4 del Nido cardioplegia, at our institution. METHODS: Data were retrospectively reviewed from all patients during 2 consecutive years (2013-2014). We switched our cardioplegia protocol from 4:1 blood cardioplegia to exclusively 1:4 single-dose del Nido cardioplegia in early 2014. A total of 408 patients were evaluated. Two hundred and forty-nine consecutive patients underwent coronary artery bypass using blood cardioplegia and 159 using del Nido Cardioplegia. RESULTS: Cardiopulmonary bypass time, cross-clamp time, in-hospital mortality and length of stay were similar (p>0.05): 63 ± 23 vs. 65 ± 21 min, 50 ± 20 vs. 52 ± 20 min, 0.8% vs. 0.6% and 6.4 ± 3 vs. 5.8 ± 3 days, respectively. For secondary outcomes: patients requiring defibrillation was 105/249 (42%) vs. 13/159 (8%) (p<0.0001), blood transfusion was required in 96/249 (38%) vs. 48/159 (30%) (p<0.085), total volume administered was 1139mL vs. 813 mL per case (p<0.0001), hematocrit change was 11.6% vs. 10.9% (p<0.04) and the mean cost per dose was $157.54 vs $5.74. CONCLUSIONS: Single-dose del Nido cardioplegia is an effective and economic cardioplegia and can be used with good outcomes in coronary surgery. Most patients have spontaneous return of sinus rhythm and there is a trend towards decreased transfusion rate.

Inflammatory cytokine response and cardiac troponin I changes in cardiopulmonary bypass using two cardioplegia solutions; del Nido and modified St. Thomas': a randomized controlled trial.

BACKGROUND: Long intervals of del Nido (DN) solution administration, 90 minutes, may result in rewarming of the myocardial tissue and elevate metabolic demand and hypoxia. This will potentially increase inflammatory response due to ischemia-reperfusion injury. We conducted this study to compare the inflammatory response between patients receiving DN and multi-dose St Thomas' cardioplegia solution (MST) in cardiopulmonary bypass (CPB) surgery for the correction of tetralogy of Fallot (TF). METHODS: Fifty-nine pediatric patients undergoing TF total correction surgery were randomly assigned into two groups: DN and MST. The patients' demographic data, blood chemistry parameters, hemodynamics and other clinical variables were recorded. TNF-a, IL-6, IL-8, IL-10 and cTnI were measured after anesthesia induction (before skin incision), immediately after cross-clamp removal and 24 hours after admission to the intensive care unit (ICU). RESULTS: Thirty-two patients of a mean age of 28.0±16.4 months received DN and 27 patients of a mean age of 24.2±15.9 months received MST. Perioperative clinical parameters were not significantly different between the two groups. Cytokine levels for all patients were significantly increased after surgery. Inter-group comparisons of cytokine levels demonstrated no significant differences in TNF-α, IL-6 and IL-8 cytokines levels. IL-10 level showed a moderately significant increase in the MST group compared to the DN group after surgery (2.94±0.9 vs. 2.46±0.61 log10 pg/mL, respectively; p=0.039). Postoperative lactate level was significantly different between two groups (2.475±1.29 vs 1.63±0.82 mg/dL in DN and MST groups, respectively; p=0.007). CTnI levels increased after surgery and remained constant until 24 hours after surgery. Significant differences between the MST and DN groups, at all times, were not detected. CONCLUSIONS: The anti-inflammatory cytokine response in the MST group is significantly better than in the DN group. This may be due to shorter intervals of the MST cardioplegia solution administration, which prevents rewarming of the myocardium, increased metabolic demand and hypoxia. Decreasing the intervals of DN administration may improve its cardioprotective properties.