Long-term outcomes following mitral valve replacement in children at heart center Leipzig: a 20-year analysis.

BACKGROUND: Although mitral valve repair is the preferred surgical strategy in children with mitral valve disease, there are cases of irreparable severe dysplastic valves that require mitral valve replacement. The aim of this study is to analyze long-term outcomes following mitral valve replacement in children in a tertiary referral center. METHODS: A total of 41 consecutive patients underwent mitral valve replacement between February 2001 and February 2021. The study data was prospectively collected and retrospectively analyzed. Primary outcomes were in-hospital mortality, long-term survival, and long-term freedom from reoperation. RESULTS: Median age at operation was 23 months (IQR 5-93), median weight was 11.3 kg (IQR 4.8-19.4 kg). One (2.4%) patient died within the first 30 postoperative days. In-hospital mortality was 4.9%. Four (9.8%) patients required re-exploration for bleeding, and 2 (4.9%) patients needed extracorporeal life support. Median follow-up was 11 years (IQR 11 months - 16 years). Long-term freedom from re-operation after 1, 5, 10 and 15 years was 97.1%, 93.7%, 61.8% and 42.5%, respectively. Long-term survival after 1, 5, 10 and 15 years was 89.9%, 87%, 87% and 80.8%, respectively. CONCLUSION: If MV repair is not feasible, MV replacement offers a good surgical alternative for pediatric patients with MV disease. It provides good early- and long-term outcomes.

[Pulmonary hypertension in adults with congenital heart disease in light of the 2022-ESC-PAH guidelines - Part II: Supportive therapy, special situations (pregnancy, contraception, non-cardiac surgery), targeted pharmacotherapy, organ transplantation, special management (shunt lesions, left ventricular disorders, univentricular hearts), interventions, intensive care, follow-up, future perspectives]. / Pulmonale Hypertonie bei Erwachsenen mit angeborenen Herzfehlern im Lichte der 2022-ESC-PAH-Leitlinien.

The number of adults with congenital heart defects (CHD) is steadily rising and amounts to approximately 360,000 in Germany. CHD is often associated with pulmonary hypertension (PH), which may develop early in untreated CHD. Despite timely treatment of CHD, PH not infrequently persists or recurs in older age and is associated with significant morbidity and mortality.The revised European Society of Cardiology/European Respiratory Society 2022 guidelines for the diagnosis and treatment of PH represent a significant contribution to the optimized care of those affected. However, the topic of "adults with congenital heart disease" is addressed only relatively superficial in these guidelines. Therefore, in the present article, this topic is commented in detail from the perspective of congenital cardiology.

"Quality of life" analysis in the long-term follow-up after "Fontan" palliation for CHDs-a single-centre experience.

BACKGROUND: Complex CHDs are life threatening, and surgical treatment is needed for survival. Fontan palliation led to a significant increase in survival rates during the last decades. Consequently, quality of life became more essential. While a reduced quality of life compared to healthy children has been reported, detailed knowledge about individual quality of life and particular areas is lacking. Furthermore, the effect of different risk factors on quality of life is only rarely evaluated. METHOD AND RESULTS: Database of the department for pediatric cardiology, Heart Center Leipzig, was screened for children after total cavopulmonary connection palliation. n = 39 patients were included in the study, the outcome after total cavopulmonary connection was analysed in detail and quality of life data were collected and analysed using the standardised questionnaire "Pediatric quality of life inventory", version 4.0. We compared the total health score of our patients to the mean score of healthy children in the literature. The mean follow-up time was 6.4 ± 3.2 years, the overall survival was 100% after maximal follow-up time of 11.1 years. We could not find any age or gender dependence, nor an influence of age at total cavopulmonary connection on the later quality of life. Yet, patients with three-staged surgery exhibited a worse quality of life than patients with two-staged palliation. Late complications might influence quality of life, but patient number is too small, to find universal results. CONCLUSION: The total cavopulmonary connection palliation affects physical and psychological quality of life as well as cardiac health independently from age and gender. More patients and longer observation should be examined to confirm the results.

Long-Term Results Following Combined Repair of Atrioventricular Septal Defect with Tetralogy of Fallot.

Atrioventricular septal defect (AVSD) in association with tetralogy of Fallot (TOF) is a rare and complex congenital cardiac malformation. We report our institutional experience and outcomes following surgical correction over a 20-year period. Patients who underwent combined surgical AVSD and TOF correction between October 2001 and February 2020 were included for analysis. All patients underwent primary repair. The study data were prospectively collected and retrospectively analyzed. Primary outcomes were in-hospital mortality and long-term freedom from reoperation. During the study period, a total of 10 consecutive patients underwent combined surgical AVSD and TOF correction. Median age at operation was 307 days (IQR 228-457) and median weight was 7.7 kg (IQR 6.7-9.5). Down Syndrome was present in six of the patients. In-hospital mortality was 0%. One patient required re-exploration due to bleeding. Median follow-up was 11 years (IQR 11 months -16 years). There was one case of reoperation due to significant residual ventricular septal defect after 2 months. None of the patients died during follow-up. Combined primary AVSD and TOF repair can be performed with low early mortality and morbidity, as well as a high long-term freedom from reoperation.

Long-term results following atrioventricular septal defect repair.

BACKGROUND: Atrioventricular septal defects (AVSD) represent 4-7% of congenital cardiac malformations. Definitive early repair is favored over prior pulmonary artery banding and delayed definitive repair in many centers. The aim of this study was to analyze long-term outcomes following AVSD repair over a 21-year period. METHODS: A total of 202 consecutive patients underwent surgical AVSD correction between June 1999 and December 2020. Surgery was performed using the double-patch technique. The study data were prospectively collected and retrospectively analyzed. Primary outcomes were In-hospital mortality and overall long-term freedom from reoperation. RESULTS: Median age at operation was 120 days (IQR 94-150), median weight was 5.0 kg (4.2-5.3). None of the patients died within the first 30 postoperative days. In-hospital mortality was 0.5% (1/202 patients). Median follow-up was 57 months (11-121). Overall freedom from reoperation at 5, 10 and 15 years was 91.8%, 86.9% and 86.9%, respectively. CONCLUSION: AVSD repair with the double-patch technique is a safe and effective procedure with good early postoperative outcomes and low long-term reoperation rates.

Influence of growth and metabolic markers on hs-troponin T and NT-proBNP levels in healthy children.

Background and objectives: As part of the LIFE Child study, we previously described the associations between N-terminal-pro-hormone brain natriuretic peptide (NT-proBNP) and hs-troponin T (hs-TnT) levels and an individual's sex, age and pubertal status, as well as with body mass index (BMI) and serum lipid levels. For NT-proBNP, we found inverse associations with advancing puberty, increasing BMI and serum lipid levels. These findings led us to further question the putative influences of the developing individual's metabolic and growth status as represented by levels of insulin-like growth factor-1 (IGF-1) and IGF-1-binding protein-3 (IGF-BP3) as well as hemoglobin A1c (HbA1c) and Cystatin C (CysC). Material and methods: Serum values, medical history and anthropometric data provided by 2522 children aged 0.25-18 years were collected and analyzed as per study protocol. Results: A strong negative association between NT-proBNP values and IGF-1, IGF-BP3 and HbA1c levels was identified. For IGF-BP3, this interaction was modulated by sex and age, for HbA1c only by age. For hs-TnT, a positive association was found with IGF-BP3, IGF-1 and CysC. The association between hs-TnT and IGF-1 was sex dependent. The association between CysC and hs-TnT was stronger in girls, but the interaction with age was only seen in boys. Between hs-TnT and HbA1c, the association was significantly negative and modulated by age. Conclusion: Based on our large pediatric cohort, we could identify age- and sex-dependent interactions between the metabolic status represented by IGF-1, IGF-BP3, CysC and HbA1c levels and the cardiac markers NT-proBNP and hs-TnT.

The association of bicuspid aortic valve on long-term outcome following one-stage repair of aortic arch obstruction associated with ventricular septal defect.

OBJECTIVE: The aim of this study was to evaluate the association of bicuspid aortic valve on contemporary outcomes, including reoperation rates, after one-stage correction for interrupted aortic arch with ventricular septal defect or for aortic coarctation with hypoplastic aortic arch and ventricular septal defect. METHODS: Seventy-four consecutive patients (35 boys, 47% and 39 girls, 53%) with interrupted aortic arch (n = 41, 55%) or aortic coarctation with hypoplastic aortic arch (n = 33, 45%) with ventricular septal defect underwent early one-stage correction. Twenty (27%) patients had bicuspid aortic valve, and the remaining 54 (73%) had a tricuspid aortic valve. The median aortic valve annulus diameter was 6.0 mm (IQR: 2.0). Patients' median age was 7 ± 29 days (range, 2-150); median weight was 3.3 ± 0.7 kg (range, 1.5-6.0), with 21 (28%) patients <3.0 kg. Selective brain perfusion through the innominate artery and selective coronary perfusion through the aortic root during aortic arch reconstruction were used in all patients. Statistical analysis was performed using SPSS version 20.0 software (SPSS Inc., Chicago, IL, USA). RESULTS: The early mortality was 1.3%. One premature neonate died in the hospital with extracorporeal membrane oxygenation after aortic coarctation plus ventricular septal defect repair. There was no further mortality. Median follow-up was 5.7 years (IQR: 10.48). Reinterventions occurred in 36 (49%) patients: balloon angioplasty in 18 (24%) patients, reoperations in 4 (5%) patients, and both in 14 (19%) patients. A total of 86 follow-up procedures were required in these 36 (49%) patients: aortic valve valvulopasty (n = 6, 8%), stent implantation (n = 8, 11%), balloon dilatation (n = 39, 53%), and reoperation (n = 33, 45%). The median time to reinterventions was 9.094 years (SE 0.890). A potential risk factor for reintervention after interrupted aortic arch and aortic coarctation with ventricular septal defect repair was bicuspid aortic valve (p = 0.019, Chi2 (1) = 5.457). In addition, a multivariate Cox analysis with backward selection and significance level <0.015 was applied to all variables that showed significant effects in univariable analyzes. This regression confirmed that bicuspid aortic valve (HR = 0.381, p = .016), and interrupted aortic arch (HR = 0.412, p = 0.043) were predictors of late reintervention. All patients had no obvious neurologic impairment in routine examinations at last follow-up. CONCLUSION: Bicuspid aortic valve was a significant risk factor for valve-related reintervention after one-stage repair for aortic arch obstruction with ventricular septal defect due to later development of stenosis associated with higher late morbidity and mortality. Particularly neonates with bicuspid aortic valve will possibly require reintervention in the future. Regular lifelong cardiac follow-up is recommended.

Prospective multicenter study of the breakable babystent for treatment of aortic coarctation in newborns and infants.

To assess the efficacy and safety of a breakable BabyStent to treat complex aortic coarctation (CoA) in early childhood. Although recommended in several guidelines, there is no approved aortic stent for young infants, because of the dilemma between two mandatory requirements: expandable up to adult size on the one hand, and small enough to fit through a baby's femoral artery on the other. Prospective interventional, multi-center clinical trial with the breakable Osypka BabyStent® (OBS). The OBS is a low-profile, 15-mm long cobalt-chromium stent, pre-mounted on a 6 mm balloon and inserted via a 4 Fr sheath. After implantation, its diameter is adjustable from 6 to 12 mm by balloon dilation. Further dilation opens predefined joints enabling unrestricted growth. Nineteen patients (9 male), median age 112 days (range: 7-539), median body weight 5.6 kg (range: 2.4-8.4) were deemed high risk and underwent stent implantation. Of those, 74% suffered from re-CoA following surgery, 53% had additional cardiac and 21% noncardiac malformations. Our primary combined endpoint was fulfilled: All stents were implanted in the desired region, and a >50% intrastenotic diameter-extension was achieved in 15 patients (78.9%, 80% confidence interval [62.2; 90.5], 95% confidence interval [54.4; 93.9]). Secondary endpoint confirmed that the OBS fits the baby's femoral vessel diameter. All children survived the procedure and 12-month follow-up. This stent enables percutaneous stenting of complex aortic coarctation to treat high-risk newborns and infants.

Pulmonary valve prostheses: patient's lifetime procedure load and durability. Evaluation of the German National Register for Congenital Heart Defects.

OBJECTIVES: We evaluated 4384 procedures performed between 1957 and 2018, collected in the National Register for Congenital Heart Defects, conducted on 997 patients with 1823 pulmonary valve replacements (PVRs), including 226 implanted via catheter [transcatheter valve (TCV)]. Main study targets are as follows: TCV benefit, valve type durability, decade-wise treatment changes and procedure frequencies over the lifetime of a PVR patient. METHODS: We studied TCV impact on surgical valve replacement (via Kaplan-Meier); pulmonary valve type-specific performance (Kaplan-Meier and Cox regressions with age group as stratification or ordinary variable); procedure interval changes over the decades (Kaplan-Meier); procedure load, i.e. frequency of any procedure/surgical PVR/interventional or surgical PVR by patient age (multistate analyses). RESULTS: TCV performance was equivalent to surgical PVRs and extended durability significantly. Homografts were most durable; Contegras lasted comparably less in older; and Hancock devices lasted less in younger patients. Matrix P-valves showed poorer performance. Age group stratification improves the precision of valve-specific explantation hazard estimations. The current median interval between procedures is 2.6 years; it became significantly shorter in most age groups below 40 years. At 30 years, 80% of patients had undergone ≥3 procedures, 20% ≥3 surgical PVRs and 42% ≥3 surgical or interventional PVRs. CONCLUSIONS: TCVs doubled freedom from explantation of conventional valves. Homografts' age group-specific explantation hazard ratio was lowest; Matrix P's hazard ratio was highest. Age-stratified Cox regressions improve the precision of prosthesis durability evaluations. The median time between procedures for PVR patients shortened significantly to 2.6 years. At 30 years, 42% had ≥3 PVRs.

Evaluation of Clinical Course and Maintenance Drug Treatment of Supraventricular Tachycardia in Children During the First Years of Life. A Cohort Study from Eastern Germany.

Supraventricular tachycardia (SVT) is considered the most common cause of arrhythmia in children and infants. Regarding the likelihood of a spontaneous resolution of SVTs during the first years of life, drug treatment aims to bridge the time until children 'grow out' out of the arrhythmia. The choice of antiarrhythmic agents and the planning of maintenance therapy are mainly based on clinical experience and retrospective single- and multi-institutional analyses and databases from all over the world approaching differently to this topic. The current study aimed to evaluate the clinical course, pharmacological treatment strategies, and constellations of risk for recurrences in the management of SVTs in children aged 3 < years. The database of the Heart Center Leipzig, Department of Pediatric cardiology, was searched for pediatric patients aged < 3 years with a clinically documented SVT between 2000 and 2019 that received pharmacologic treatment. Patients with complex congenital heart disease or arrhythmias following cardiac surgery were excluded. 69 patients were included. Pharmacologic treatment, follow-up schedule, recurrences, outcomes, and risk factors for complicated courses are reported. Drug therapy of SVTs in young children remains a controversial topic with heterogeneous treatment and follow-up strategies applied. Risk factors for recurrences and/or stubborn clinical courses are difficult rhythm control with 3 or more antiarrhythmic drugs, ectopic atrial tachycardias, and a first occurrence of the SVT in the fetal period. Prospective studies are needed to sufficiently evaluate optimal treatment strategies.

Physiologic effects and functional outcome after treatment of dysfunctional right ventricular outflow tract in congenital heart disease using a two-stage intervention.

BACKGROUND: Pathophysiological differences in relief of pulmonary stenosis (PS) as opposed to pulmonary regurgitation (PR) by percutaneous pulmonary valve implantation (PPVI) remain elusive, but might impact current assessment of procedural success and ultimately indications. METHODS: Invasive pressure measurements, cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed before pre-stenting (BMS), after BMS and after PPVI in patients with either PS or PR. RESULTS: In PS (n = 14), BMS reduced the right ventricular (RV) to systemic pressure ratio (0.8 ± 0.2 vs. 0.4 ± 0.1%; p < .01), improved RF EF (53 ± 14 vs. 59 ± 12%; p = .01) but introduced free PR (PR fraction post 39 ± 12%; p < .01) with no changes in effective RV stroke volume (SV). PPVI eliminated PR (PR fraction 5 ± 3%; p < .01) and improved effective RV SV (p < .01) with no changes in RV EF (p = .47). Peak VO2 improved significantly after BMS, with no changes following PPVI (26 ± 9 vs. 30 ± 11 vs. 31 ± 10 ml/kg*min). In PR (n = 14), BMS exaggerated PR (PR fraction post 47 ± 10) with reduction in effective RV SV (pre 43 ± 9 vs. post 38 ± 8 ml/m2; p = .01), which improved after PPVI (post PPVI 49 ± 9 ml/m2; p < .01), secondary to elimination of PR (PR fraction 5 ± 4%; p < .01). RV EF (pre 53 ± 11 vs. post 53 ± 9 vs. post PPVI 50 ± 9%) and Peak VO2 (pre 22 ± 7 vs. post 21 ± 7 vs. post PPVI 23 ± 7 ml/kg*min) remained unchanged. CONCLUSIONS: Exercise capacity in patients with right ventricular outflow tract dysfunction is primarily afterload-dependent.

Qualification, knowledge, tasks and responsibilities of the clinical perfusionist in Germany.

Consensus paper of the German Society of Cardiovascular Engineering, the German Society for Thoracic and Cardiovascular Surgery, the German Society of Cardiology, the German Society of Pediatric Cardiology, the German Society of Anesthesiology and Intensive Care Medicine, the German Interdisciplinary Association of Intensive Care Medicine and Emergency Medicine and the German Society of Medical Intensive Care and Emergency Medicine.

Anti-oxidative or anti-inflammatory additives reduce ischemia/reperfusions injury in an animal model of cardiopulmonary bypass.

Severe inborn cardiac malformations are typically corrected in cardioplegia, with a cardio-pulmonary bypass (CPB) taking over body circulation. During the operation the arrested hearts are subjected to a global ischemia/reperfusion injury. Although the applied cardioplegic solutions have a certain protective effect, application of additional substances to reduce cardiac damage are of interest.18 domestic piglets (10-15 kg) were subjected to a 90 min CPB and a 120 min reperfusion phase without or with the application of epigallocatechin-3-gallate (10 mg/kg body weight) or minocycline (4 mg/kg body weight), with both drugs given before and after CPB. 18 additional sham-operated piglets without or with epigallocatechin-3-gallate or minocycline served as controls. In total 36 piglets were analyzed (3 CPB-groups and 3 control groups without or with epigallocatechin-3-gallate or minocycline respectively; 6 piglets per group). Hemodynamic and blood parameters and ATP-measurements were assessed. Moreover, a histological evaluation of the heart muscle was performed. RESULTS: Piglets of the CPB-group needed more catecholamine support to achieve sufficient blood pressure. Ejection fraction and cardiac output were not different between the 6 groups. However, cardiac ATP-levels and blood lactate were significantly lower and creatine kinase was significantly higher in the three CPB-groups. Markers of apoptosis, hypoxia, nitrosative and oxidative stress were significantly elevated in hearts of the CPB-group. Nevertheless, addition of epigallocatechin-3-gallate or minocycline significantly reduced markers of myocardial damage. Noteworthy, EGCG was more effective in reducing markers of hypoxia, whereas minocycline more efficiently decreased inflammation. CONCLUSIONS: While epigallocatechin-3-gallate or minocycline did not improve cardiac hemodynamics, markers of myocardial damage were significantly lower in the CPB-groups with epigallocatechin-3-gallate or minocycline supplementation.

ChyloBEST: Chylothorax in Infants and Nutrition with Low-Fat Breast Milk.

Chylothorax occurs in 2.8-5% of infants after cardiac surgery and can increase morbidity and mortality. First-line conservative treatment consists of a chest tube drainage and a fat-free and medium-chain triglyceride (MCT)-enriched diet. This typically leads to a discontinuity of breast milk feeding due to high content of long-chain triglycerides within the breast milk. Modified breast milk with low fat content (LFBM) could provide numerous benefits like immunological properties of breast milk even for patients with chylothorax. This study was conducted at Herzzentrum Leipzig comparing clinical and growth outcomes between infants with chylothorax after surgery for congenital heart disease treated with LFBM (n = 13) versus MCT-Formula (n = 10). LFBM was prepared by centrifugation of native breast milk added with MCT-oil and fortifier. There were no differences in volume and duration of chest tube drainage between LFBM and MCT-formula treatment groups. Furthermore, no statistically significant differences with regard to weight and length gains could be observed between both feeding groups. LFBM is an efficient and unharmful treatment for chylothorax following cardiac surgery in young children.

Feasibility, safety and diagnostic impact of endomyocardial biopsies for the diagnosis of myocardial disease in children and adolescents.

AIMS: Endomyocardial biopsies (EMBs) are performed infrequently in children owing to significant past complication rates and controversial discussions about the therapeutic value of results. The objective of this study was to investigate the safety and feasibility of EMBs for suspected myocardial disease in relation to their clinical value. METHODS AND RESULTS: We performed a retrospective multicentre review of the Working Group for Interventional Cardiology of the German Society for Paediatric Cardiology. During three consecutive years, 206 EMBs (84 female/mean age 8.95±6.62 years) were performed and analysed at 15 heart centres. In the majority of cases, biopsies were taken from the right ventricle (RV/89.8%; p<0.001). The overall complication rate was 9.7%, whereas major complications occurred in only 0.97% of cases. Risk factors associated with a higher complication rate were biopsy during the first year of life (20.5%) and from the left ventricle (31.1%) (p<0.05). There was no procedure-related mortality. Treatment was changed in 18.0% of cases based on biopsy results. CONCLUSIONS: Today, endomyocardial biopsies in older children with suspected myocardial disease can be performed safely with a low risk of major complications and mortality, whereas the risk of complications if the biopsy is carried out in the first year of life or taken from the left ventricle remains high.

Bloodless priming of the cardiopulmonary bypass circuit: determinants of successful transfusion-free operation in neonates and infants with a maximum body weight of 7 kg.

We currently perform open-heart procedures using bloodless priming of cardiopulmonary bypass circuits regardless of a patient's body weight. This study presents results of this blood-saving approach in neonates and infants with a body weight of up to 7 kg. It tests with multivariate analysis factors that affect perioperative transfusion. A total of 498 open-heart procedures were carried out in the period 2014-2016 and were analysed. Priming volume ranged from 73 ml for patients weighing up to 2.5 kg to 110 ml for those weighing over 5 kg. Transfusion threshold during cardiopulmonary bypass was 8 g/dl of haemoglobin concentration. Transfusion factors were first analysed individually. Variables with a p-value lower than 0.2 underwent logistic regression. Extracorporeal circulation was conducted without transfusion of blood in 335 procedures - that is, 67% of cases. Transfusion-free operation was achieved in 136 patients (27%) and was more frequently observed after arterial switch operation and ventricular septal defect repair (12/18=66.7%). It was never observed after Norwood procedure (0/33=0%). Lower mortality score (p=0.001), anaesthesia provided by a certain physician (p=0.006), first chest entry (p=0.013), and higher haemoglobin concentration before going on bypass (p=0.013) supported transfusion-free operation. Early postoperative mortality was 4.4% (22/498). It was lower than expected (6.4%: 32/498). In conclusion, by adjusting the circuit, cardiopulmonary bypass could be conducted without donor blood in majority of patients, regardless of body weight. Transfusion-free open-heart surgery in neonates and infants requires team cooperation. It was more often achieved in procedures with lower mortality score.

Epigallocatechin Gallate Reduces Ischemia/Reperfusion Injury in Isolated Perfused Rabbit Hearts.

Cardioplegic arrest during heart operations is often used in cardiac surgery. During cardioplegia, the heart is subjected to a global ischemia/reperfusion-injury. (-)-epigallocatechin gallate (EGCG), one of the main ingredients of green tea, seems to be beneficial in various cardiac diseases. Therefore, the aim of our study was to evaluate EGCG in a rabbit model of cardioplegic arrest. Twenty four mature Chinchilla rabbits were examined. Rabbit hearts were isolated and perfused according to Langendorff. After induction of cardioplegia (without and with 20 µmol/L EGCG, n = 6 each) the hearts maintained arrested for 90-min. Thereafter, the hearts were re-perfused for 60 min. During the entire experiment hemodynamic and functional data were assessed. At the end of each experiment, left ventricular samples were processed for ATP measurements and for histological analysis. Directly after cessation of cardioplegia, all hearts showed the same decline in systolic and diastolic function. However, hearts of the EGCG-group showed a significantly faster and better hemodynamic recovery during reperfusion. In addition, tissue ATP-levels were significantly higher in the EGCG-treated hearts. Histological analysis revealed that markers of nitrosative and oxidative stress were significantly lower in the EGCG group. Thus, addition of EGCG significantly protected the cardiac muscle from ischemia/reperfusion injury.

Olesoxime Inhibits Cardioplegia-Induced Ischemia/Reperfusion Injury. A Study in Langendorff-Perfused Rabbit Hearts.

Objective: During cardioplegia, which is often used in cardiac surgery, the heart is subjected to global ischemia/reperfusion injury, which can result in a post-operative impairment of cardiac function. Mitochondria permeability transition pores (MPTP) play a key role in cardiomyocyte survival after ischemia/reperfusion injury. It was shown in clinical settings that blockers of MPTP like cyclosporine might have a positive influence on cardiac function after cardioplegic arrest. Olesoxime, which is a new drug with MPTP blocking activity, has been introduced as a neuroprotective therapeutic agent. This drug has not been investigated on a possible positive effect in ischemia/reperfusion injury in hearts. Therefore, the aim of our study was to investigate possible effects of olesoxime on cardiac recovery after cardioplegic arrest. Methods: We evaluated 14 mature Chinchilla bastard rabbits of 1,500-2,000 g. Rabbit hearts were isolated and perfused with constant pressure according to Langendorff. After induction of cardioplegic arrest (30 ml 4°C cold Custodiol cardioplegia without and with 5 µmol/L olesoxime, n = 7 each) the hearts maintained arrested for 90-min. Thereafter, the hearts were re-perfused for 60 min. At the end of each experiment left ventricular samples were frozen in liquid nitrogen for ATP measurements. Furthermore, heart slices were embedded in paraffin for histological analysis. During the entire experiment hemodynamic and functional data such as left ventricular pressure (LVP), dp/dt(max) and (min), pressure rate product (PRP), coronary flow, pO2, and pCO2 were also assessed. Results: Histological analysis revealed that despite the same ischemic burden for both groups markers of nitrosative and oxidative stress were significantly lower in the olesoxime group. Moreover, hearts of the olesoxime-group showed a significantly faster and better hemodynamic recovery during reperfusion. In addition, tissue ATP-levels were significantly higher in the olesoxime treated hearts. Conclusions: Olesoxime significantly protected the cardiac muscle from ischemia/reperfusion injury.

Neuroprotective Strategies during Cardiac Surgery with Cardiopulmonary Bypass.

Aortocoronary bypass or valve surgery usually require cardiac arrest using cardioplegic solutions. Although, in principle, in a number of cases beating heart surgery (so-called off-pump technique) is possible, aortic or valve surgery or correction of congenital heart diseases mostly require cardiopulmonary arrest. During this condition, the heart-lung machine also named cardiopulmonary bypass (CPB) has to take over the circulation. It is noteworthy that the invention of a machine bypassing the heart and lungs enabled complex cardiac operations, but possible negative effects of the CPB on other organs, especially the brain, cannot be neglected. Thus, neuroprotection during CPB is still a matter of great interest. In this review, we will describe the impact of CPB on the brain and focus on pharmacological and non-pharmacological strategies to protect the brain.

A Low-Cost Simulation Model for R-Wave Synchronized Atrial Pacing in Pediatric Patients with Postoperative Junctional Ectopic Tachycardia.

BACKGROUND: Postoperative junctional ectopic tachycardia (JET) occurs frequently after pediatric cardiac surgery. R-wave synchronized atrial (AVT) pacing is used to re-establish atrioventricular synchrony. AVT pacing is complex, with technical pitfalls. We sought to establish and to test a low-cost simulation model suitable for training and analysis in AVT pacing. METHODS: A simulation model was developed based on a JET simulator, a simulation doll, a cardiac monitor, and a pacemaker. A computer program simulated electrocardiograms. Ten experienced pediatric cardiologists tested the model. Their performance was analyzed using a testing protocol with 10 working steps. RESULTS: Four testers found the simulation model realistic; 6 found it very realistic. Nine claimed that the trial had improved their skills. All testers considered the model useful in teaching AVT pacing. The simulation test identified 5 working steps in which major mistakes in performance test may impede safe and effective AVT pacing and thus permitted specific training. The components of the model (exclusive monitor and pacemaker) cost less than $50. Assembly and training-session expenses were trivial. CONCLUSIONS: A realistic, low-cost simulation model of AVT pacing is described. The model is suitable for teaching and analyzing AVT pacing technique.