Long-term transplant outcomes of donor hearts with left ventricular dysfunction.

OBJECTIVE: Despite small single-center reports demonstrating acceptable outcomes using donor hearts with left ventricular dysfunction, 19% of potential donor hearts are currently unused exclusively because of left ventricular dysfunction. We investigated modern long-term survival of transplanted donor hearts with left ventricular dysfunction using a large, diverse cohort. METHODS: Using the United Network for Organ Sharing database, we reviewed all adult heart transplants between January 2000 and March 2016. Baseline and postoperative characteristics and Kaplan-Meier survival curves were compared. A covariates-adjusted Cox regression model was developed to estimate post-transplant mortality. To address observed variation in patient profile across donor ejection fraction, a propensity score was built using Cox predictors as covariates in a generalized multiple linear regression model. All the variables in the original Cox model were included. For each recipient, a predicted donor ejection fraction was generated and exported as a new balancing score that was used in a subsequent Cox model. Cubic spline analysis suggested that at most 3 and perhaps no ejection fraction categories were appropriate. Therefore, in 1 Cox model we added donor ejection fraction as a grouped variable (using the spline-directed categories) and in the other as a continuous variable. RESULTS: A total of 31,712 donor hearts were transplanted during the study period. A total of 742 donor hearts were excluded for no recorded left ventricular ejection fraction, and 20 donor hearts were excluded for left ventricular ejection fraction less than 20%. Donor hearts with reduced left ventricular ejection fraction were from younger donors, more commonly male donors, and donors with lower body mass index than normal donor hearts. Recipients of donor hearts with reduced left ventricular ejection fraction were more likely to be on mechanical ventilation. Kaplan-Meier curves revealed no significant differences in recipient survival up to 15 years of follow-up (P = .694 log-rank test). Cox regression analysis showed that after adjustment for propensity variation, transplant year, and region, ejection fraction had no statistically significant impact on mortality when analyzed as a categoric or continuous variable. Left ventricular ejection fraction at approximately 1 year after transplantation was normal for all groups. CONCLUSIONS: Carefully selected donor hearts with even markedly diminished left ventricular ejection fraction can be transplanted with long-term survival equivalent to normal donor hearts and therefore should not be excluded from consideration on the basis of depressed left ventricular ejection fraction alone. Functional recovery of even the most impaired donor hearts in this study suggests that studies of left ventricular function in the setting of brain death should be interpreted cautiously.

Debranching of Supra-aortic Vessels via Femoral Artery Inflow for Late Ascending Aortic Rupture.

A 56-year-old man with a history of Marfan's syndrome, total arch replacement, descending thoracic endovascular aortic repair, and twice redo sternotomy for pseudoaneurysm repair, presented with a pulsatile chest mass secondary to a contained rupture of the ascending aorta. The patient underwent supra-aortic debranching via the superficial femoral artery and ascending thoracic stent-graft placement under continuous transesophageal echocardiography. Completion angiography demonstrated successful exclusion of the contained rupture. Postoperatively, the patient was neurologically intact, the pulsatile mass resolved, and the bypass grafts remained patent. Chronic respiratory failure and multidrug-resistant pneumonia led to late mortality. This case demonstrates that hybrid repair is effective in the emergent setting of ascending aortic rupture. Debranching of the ascending arch using the superficial femoral artery as inflow is feasible and provides adequate cerebral perfusion despite the length of the bypass. The use of transesophageal echocardiography during stent-graft deployment allows precise device placement in the high-risk area of the ascending aorta proximal to the innominate artery.

Subaortic Stenosis Resection in Children: Emphasis on Recurrence and the Fate of the Aortic Valve.

BACKGROUND: Recurrence after surgical resection of discrete subvalvar aortic stenosis in children often requires repeat operation. Risk factors for recurrence are poorly understood. We sought to determine potential risk factors for recurrence and postoperative comorbidities in the long term. METHODS: Retrospective chart review was performed on all pediatric patients who underwent surgical resection of discrete subaortic stenosis at our institution. Demographics, perioperative findings, and clinical data were analyzed for predisposing factors. RESULTS: From 1991 to 2015, a total of 104 patients underwent primary surgical resection of discrete subaortic stenosis. There were no postoperative deaths. Three (2.9%) patients required pacemaker implantation. Nine (8.4%) patients required repeat resection for recurrence of subaortic membrane over a median follow-up of 8.5 years (interquartile range: 5.9-13.5 years). Actuarial freedom from repeat resection was 100%, 94%, and 82% at one, five, and ten years, respectively. Repeat resection occurred more frequently in patients with genetic disease (37.5% vs 10.7%; P = .033) and preoperative mitral regurgitation (MR; 25% vs 1.2%; P < .001). Postoperative aortic insufficiency (AI) that was moderate or worse was associated with older age at the time of first resection (relative risk [RR]: 1.54, P < .05), moderate or severe preoperative AI (RR: 1.84, P = .002), and repeat resection of subaortic stenosis (RR: 1.90, P < .001). CONCLUSION: The majority of children who undergo surgical resection of subaortic stenosis will not experience recurrence in childhood and those who do require repeat resection may have a higher incidence of genetic disease and preoperative MR. Postoperative AI is associated with repeat resection, older age at the time of surgery, and degree of preoperative AI.

Short-term hypoxia improves early cardiac progenitor cell function in vitro.

The use of cardiovascular progenitor cells (CPCs) to repair damaged myocardium has been the focus of intense research. Previous reports have shown that pretreatments, including hypoxia, improve cell function. However, the age-dependent effects of short-term hypoxia on CPCs, and the role of signaling in these effects, are unknown. Cloned neonatal and adult CPCs expressing Isl1, c-Kit, KDR, PDGFRA, and CXCR4, were preconditioned using hypoxia (1% O2 for six hours). Intracellular signaling pathway changes were modeled using Ingenuity Pathway Analysis (IPA), while qRT-PCR, flow cytometry, and immunoblotting were used to measure pathway activation. Cellular function, including survival, cell cycle, and invasion, were evaluated using a TUNEL assay, flow cytometry, and a Transwell® invasion assay, respectively. IPA predicted, and RT-PCR and flow cytometry confirmed, that the PI3K/AKT pathway was activated following short-term hypoxia. Heat shock protein (HSP) 40 expression increased significantly in both age groups, while HSP70 expression increased only in neonatal CPCs. Neonatal CPC invasion and survival improved after hypoxia pre-treatment, while no effect was observed in cell cycling and developmental status. Prostaglandin receptor expression was enhanced in neonatal cells. Prior to transplantation, hypoxic preconditioning enhances CPC function, including invasion ability and pro-survival pathway activation.

Effect of left ventricular dysfunction on utilization of donor hearts.

BACKGROUND: In this study we investigated modern, non-utilization rates of potential cardiac donors with left ventricular dysfunction (LVD) to clarify this phenomenon's magnitude and the impact of recent studies suggesting these organs can be safely transplanted. METHODS: Using the United Network for Organ Sharing transplant database, we reviewed all donors evaluated between January 1, 2007 and June 30, 2014. Exclusion criteria included lack of consent and age <13 or >59 years. The number of hearts not transplanted due to non-cardiac causes, structural disease, "other" (previous cardiac surgery, donation after cardiac death, etc.) and isolated LVD was determined and a covariates-adjusted Poisson regression model with robust standard errors was developed to estimate non-utilization relative risk (RR) with 95% confidence interval (CI) for LVD. Heart disposition for potential donor hearts was determined separately for 2 previous eras (1990 to 1999 and 2000 to 2006), and trends were evaluated. RESULTS: There were 60,789 donors assessed. Of the 44,829 organs meeting the inclusion criteria, 15,654 (34.92%) were transplanted and 29,175 (65.08%) were not. Of the non-utilized hearts, 15,512 (34.60%) were declined for non-cardiac reasons, 1,051 (2.34%) for structural disease, 4,073 (9.09%) for "other" and 8,539 (19.05%) exclusively for LVD. Of this last category, 4,950 (11.04%) lacked documented evidence of LVD. Covariates-adjusted RR for non-utilization showed that, for every 10% increase in LV ejection fraction, the risk of non-utilization decreased by 20% (RR = 0.80, 95% CI 0.79 to 0.81). Analysis of era-effect demonstrated significantly decreased overall utilization of donor hearts, with increases in the number of hearts not transplanted across all categories over time (p < 0.001). CONCLUSIONS: Roughly 20% of potential cardiac donors are excluded due to LVD. This figure has not been impacted by recent studies indicating that these hearts may be used safely. More complete data are required to understand why 11.04% of hearts that met inclusion criteria were refused for "poor function" without documented evidence.

A Hyper-Crosslinked Carbohydrate Polymer Scaffold Facilitates Lineage Commitment and Maintains a Reserve Pool of Proliferating Cardiovascular Progenitors.

BACKGROUND: Cardiovascular progenitor cells (CPCs) have been cultured on various scaffolds to resolve the challenge of cell retention after transplantation and to improve functional outcome after cell-based cardiac therapy. Previous studies have reported successful culture of fully differentiated cardiomyocytes on scaffolds of various types, and ongoing efforts are focused on optimizing the mix of cardiomyocytes and endothelial cells as well as on the identification of a source of progenitors capable of reversing cardiovascular damage. A scaffold culture that fosters cell differentiation into cardiomyocytes and endothelial cells while maintaining a progenitor reserve would benefit allogeneic cell transplantation. METHODS: Isl-1 + c-Kit + CPCs were isolated as clonal populations from human and sheep heart tissue. After hyper-crosslinked carbohydrate polymer scaffold culture, cells were assessed for differentiation, intracellular signaling, cell cycling, and growth factor/chemokine expression using real time polymerase chain reaction, flow cytometry, immunohistochemistry, and calcium staining. RESULTS: Insulin-like growth factor 1, hepatocyte growth factor, and stromal cell derived factor 1α paracrine factors were induced, protein kinase B signaling was activated, extracellular signal-regulated kinase phosphorylation was reduced and differentiation into both cardiomyocytes and endothelial cells was induced by scaffold-based cell culture. Interestingly, movement of CPCs out of the G1 phase of the cell cycle and increased expression of pluripotency genes PLOU5F1 (Oct4) and T (Brachyury) within a portion of the cultured population occurred, which suggests the maintenance of a progenitor population. Two-color immunostaining and 3-color fluorescence-activated cell sorting analysis confirmed the presence of both Isl-1 expressing undifferentiated cells and differentiated cells identified by troponin T and von Willebrand factor expression. Ki-67 labeling verified the presence of proliferating cells that remained in situ alongside the differentiated functional derivatives. CONCLUSIONS: Cloned Isl-1 + c-kit + CPCs maintained on a hyper-cross linked polymer scaffold retain dual potential for proliferation and differentiation, providing a scaffold-based stem cell source for transplantation of committed and proliferating cardiovascular progenitors for functional testing in preclinical models of cell-based repair.

Atrial fibrillation and flutter following coronary artery bypass graft surgery: A retrospective study and review.

INTRODUCTION AND OBJECTIVES: Atrial fibrillation is a common arrhythmia following coronary artery bypass graft surgery. Its incidence can range from 10 to 60% of patients undergoing coronary artery bypass graft. This rhythm can result in shorter or longer intervals between beats. METHODS: Medical records of 143 patients from the Queen's Medical Center, Kuakini Medical Center, Saint Francis Medical Center, and Straub Hospital and Clinic, all of which are located in Honolulu, Hawaii were reviewed. An additional 39 records of patients who did not develop these complications were also reviewed as a control group. Patients were selected according to the ICD codes for atrial fibrillation/flutter and coronary artery bypass graft. Both anomalies can lead to increased health care costs, morbidity, and mortality. In this study, possible predisposing factors to these complications were investigated. The time of onset, weight gain, elapsed time, fluid status (in/out), hematocrit, and drug regimens were compared between the two groups. RESULTS: The differences in weight gain, fluid status, and hematocrit between the groups were not significant. There were a total of 17 different drugs prescribed to the group as a whole but not every patient received the same regimen. CONCLUSIONS: Atrial fibrillation and flutter were found to be more common in males, particularly between the ages of 60 and 69 years. There were no other significant findings.

Left thoracotomy: an ideal approach for mitral valve replacement in patient with severe chest wall deformity.

We report a 65-year-old woman with chronic diastolic congestive heart failure, pulmonary hypertension, and severe mitral valve regurgitation. She was not a candidate for percutaneous mitral valve repair and was turned down for an open heart operation by 2 institutions based on her severe pectus excavatum deformity. A left posterior lateral thoracotomy approach provided excellent exposure for central cannulation and replacement of the mitral valve.

A rare case of hepatic duct injury from blunt abdominal trauma.

BACKGROUND: A 25 year-old male was brought to the emergency room following an apparent suicide attempt by jumping from the fourth floor. CASE REPORT: Patient had a large abdominal laceration in the right upper quadrant (RUQ). CT scan showed a sub-scapular hematoma of the liver. Due to the repeated episodes of hypotension, a laporotomy was performed and the left hepatic artery was ligated while the ductal injury was managed with a Roux-en-Y left hepatic jejunostomy and stent. Bile leakage was resolved post-operatively by day 5 and the patient was discharged home on day 13 after clearance from psychiatry. CONCLUSIONS: While non-iatrogenic extrahepatic biliary trauma is rare, a high degree of suspicion is essential, especially in cases like the one discussed in this report. Diagnosis can be difficult in patients undergoing observation.

Blake drains: a novel method of chest drainage after extracardiac fontan operation with autologous pericardium.

BACKGROUND: Pleural effusions after Fontan palliation remain a cause of increased length of stay, cost, and morbidity. We report our experience with Blake drains (BDs) and the outpatient pediatric pleural drain pathway after Fontan operation. METHODS: A retrospective chart review was performed on all patients who underwent extracardiac lateral tunnel (ECLT) Fontan operation with pedicled autologous pericardium. Patients with prolonged pleural drainage were analyzed for predisposing factors. RESULTS: From March 1995 to December 2009, 162 patients (92 male, 56.8%) underwent ECLT Fontan operation. The median age at the time of Fontan operation was 30.9 months; the median weight was 12.9 kg. The median hospital stay was 4 days, and the median pleural drain requirement was 13 days. Prolonged pleural effusions occurred in 59 patients (36.4%), with prolonged cardiopulmonary bypass time identified as the only significant risk factor (p=0.04). Sixty patients (37%) were readmitted within 30 days of operation, with effusion requiring additional pleural drainage (n=41, 68.3%), infection (n=8, 13.3%), or a combination of the two (n=3, 5%) being the most common reason. There were two early deaths, neither of which was associated with BD malfunction. The BD clinical pathway for ECLT Fontan operation reduced our institutional cost to about $38,000 per patient, which represents a significant savings compared with traditional management with extended hospital stay after Fontan operation. CONCLUSIONS: Silicone BDs are safe and effective after ECLT Fontan operation. Hospital length of stay and cost can be significantly decreased when these drains are used with appropriate family involvement and close outpatient surveillance.

Amelioration of ischemia-reperfusion injury in an isolated rabbit lung model using OXANOH.

OBJECTIVE: Acute respiratory distress syndrome (ARDS) remains a major cause of morbidity and mortality. Oxygen-free radicals (OFRs) produced during ischemia and reperfusion (IR) have been implicated as the final common pathway in the pathogenesis of this syndrome. Spin traps have been shown to decrease IR injury in several animal lung models. The hydroxylamine, OXANOH (2-ethyl-2,5,5-trimethyl-3-oxazolidine) has been proposed as an ideal spin trap that would trap extra- and intracellular OFRs producing the stable radical, OXANO• (2-ethyl-2,5,5-trimethyl-3-oxazolidinoxyl). Electron microscopy was used to investigate whether OXANOH would protect against IR injury in the rabbit lung. METHODS: OXANOH was obtained by hydrogenation of its stable radical, OXANO• using a safe laboratory technique. Several doses of OXANOH were tested to identify a nontoxic dose. Two quantitative methods were used based on the average surface area of the alveoli and average number of alveoli per unit surface area using scanning electron microscopy (SEM). A total of 20 animals were subjected to 2 hours of ischemia followed by 4 hours of reperfusion. On reperfusion, the 4 groups (N = 5) received no treatment, OXANOH, superoxide dismutase (SOD)/catalase, or oxypurinol. RESULTS: A therapeutic dose of 250 µmol/L of OXANO• was suggested in this in vitro model. All the 3 treatments showed significantly less injury compared to the control group and that SOD/catalase was significantly different from OXANOH and oxypurinol (P < .008). CONCLUSION: OXANOH ameliorated IR injury in the isolated rabbit lung, almost as effectively as SOD/catalase and oxypurinol.

In situ pericardial extracardiac lateral tunnel Fontan operation: fifteen-year experience.

BACKGROUND: The study purpose is to evaluate the long-term outcome of the in situ pericardial extracardiac lateral tunnel Fontan operation. METHODS: From June 1994 to August 2009, 160 patients with single ventricle (boys, n = 96, 60%, median age = 39 months, mean weight 15.5 kg) underwent the pedicled pericardial extracardiac lateral tunnel operation. Patients' charts were reviewed for perioperative and long-term follow-up data, outcome, and mortality. The potential growth of these tunnels was evaluated. RESULTS: The main diagnoses included tricuspid atresia (n = 44, 27%); double-outlet right ventricle (n = 29, 18%), and hypoplastic left heart syndrome (n = 26, 16%). The mean follow-up was 6.5 ± 3.7 years (range: 0.1-15 years). There were 2 (1.3%) operative and 6 (3.7%) late deaths. Actuarial survival at 14 years was 93%. Early complications included prolonged effusions (n = 35, 22%), chylothorax (n = 5, 3.1%), readmissions (n = 35, 22%), cerebrovascular accidents (n = 8, 5%), contralateral phrenic nerve palsy (n = 1, 0.8%), and transient arrhythmias (n = 5, 3.1%). No pacemaker was needed. Late complications included tunnel stenosis (n = 3, 1.8%) managed with balloon dilatation and stenting in 2 patients and surgical revision in 1; tunnel thrombosis (n = 2, 1.2%) causing death in both patients; and protein losing-enteropathy (n = 4, 2.5%). Follow-up echocardiography of 10 patients showed laminar flow, no turbulence/gradient at the inferior vena cava and mid-tunnel levels. The diameter indexed to body surface area showed growth, reduction, or no change depending on flow demands. CONCLUSIONS: The construction of the extracardiac lateral tunnel Fontan conduit using viable pedicled pericardium is a relatively simple, durable, and safe operation. Long-term follow-up confirms low morbidity and mortality. Fenestration is unnecessary in most patients. This viable tunnel adapts to physiologic flow demands.

Mortality reduction with beta-blockers in ischemic cardiomyopathy patients undergoing coronary artery bypass grafting.

Coronary artery bypass grafting (CABG) in patients with systolic heart failure (HF) carries high morbidity and mortality rates. Reducing perioperative mortality with beta-blockers (BBs) may help improve outcomes. Analysis of 4903 patients who underwent isolated CABG surgery was performed. In-hospital mortality of systolic HF patients who received BBs was 2.03%; systolic HF patients who did not receive BBs had a mortality of 5.20%. Thirty-day mortality was 2.98% in the patients with systolic HF who received BBs and 6.16% in the patients who did not. beta-Blockade did not affect the mortality in patients with preserved systolic function. Cardiogenic shock was a predictor of increased mortality in patients with systolic HF, while BBs reduced mortality. BBs are associated with decreased in-hospital and 30-day mortality in patients with systolic HF. BB therapy should be considered in patients with systolic HF who are undergoing CABG.

Modification of ventricular-to-pulmonary shunt to minimize proximal conduit obstruction after stage I Norwood reconstruction.

The use of right ventricle-to-pulmonary artery conduit improved postoperative hemodynamics and survival in hypoplastic left heart syndrome patients. Proximal conduit anastomosis obstruction prompts hypercyanosis and early bidirectional Glenn connection. We describe modification of the proximal right ventricle-to-pulmonary artery conduit anastomosis to eliminate this complication. Outcomes after Norwood operation using standard Sano (group II) versus modified (group I) right ventricle-to-pulmonary artery conduit anastomosis were evaluated. Group II patients had more hospital readmissions for cyanosis (19 vs 1; p < or = 0.05), the Glenn operation at younger age (4.4 vs 5.6 months), and more proximal stenosis (3 [20%] vs zero; p < or = 0.05) than group I. This modification may eliminate progressive proximal stenosis.

Improving outcomes through the use of surgical sealants for anastomotic sealing during cardiovascular surgery.

The continued need to minimize blood product usage both during and after cardiac surgical procedures has been challenged by a changing patient population, and most recently by the withdrawal of the antifibrinolytic aprotinin (Trasylol, Bayer Pharmaceuticals, West Haven, CT, USA) from the market. To meet these challenges, a variety of topical hemostatic tools have continued to emerge in the surgical armamentarium. These include hemostatic agents, adhesives, and sealants designed to control perioperative bleeding and decrease blood product utilization. Optimal application of novel topical adjuncts can be limited due to the lack of clarity on how to differentiate between these adjunctive hemostatic products and their appropriate uses. This paper will review the classes of these products, how and where such products can be used during cardiovascular surgery for achieving hemostasis, and the potential for improved outcomes through the appropriate selection and use of these agents.

Pediatric transplantation using hearts refused on the basis of donor quality.

BACKGROUND: There is always more demand than supply of organs in pediatric heart transplantation. Yet, potential donor organs are regularly declined for a variety of reasons, among them donor organ quality as determined by United Network for Organ Sharing (UNOS) refusal code 830 or its equivalent. METHODS: For the study group institutional and UNOS databases (July 2000 to December 2008) were reviewed to examine outcomes of pediatric heart transplantation using donor hearts that had been previously refused one or more times because of organ quality. Variation between outcomes of this cohort and recipients who received primarily offered heart grafts in a single institution was analyzed. RESULTS: In 29 recipients, transplantation or retransplantation was with heart grafts previously declined on the basis of quality. Recovery distances (p < 0.002) and graft cold ischemic times (p < 0.001) were significantly longer for declined hearts. Operative survival was 93% +/- 5.0% (27 of 29). Seven-year actuarial survival was 74% +/- 10.5%. At the present time, 24 of the 29 recipients (83%) are alive. These results do not vary statistically from those experienced by 84 recipients of 86 primarily offered donor organs during the same time. CONCLUSIONS: Despite longer distance recovery (ie, longer graft cold ischemic times), outcomes of pediatric heart transplantation using donor heart grafts refused on the basis of organ quality are highly competitive. Pediatric donor hearts should seldom be declined on the basis of organ quality (UNOS code 830).

Ischemia-reperfusion injury in the lung: quantitation using electron microscopy.

BACKGROUND: The primary objectives of this study were to determine the time course of ischemia-reperfusion injury in an isolated rabbit lung model and to quantify this damage using electron microscopic methodology coupled with statistical analyses. MATERIALS AND METHODS: Eight groups of isolated rabbit lungs (n = 5 per group) were subjected to predetermined periods of ischemia-reperfusion. Two hours of ischemia and 4 hours of reperfusion were concluded to be necessary to induce optimal ischemia-reperfusion injury in this model. Four other groups were subjected to 2 hours of ischemia followed by selected periods of reperfusion. These groups were compared to 4 control groups that were perfused for comparable time periods but without the initial ischemia. New quantitative methods were developed based on the average surface area of the alveoli and average number of alveoli per unit surface area, using scanning electron microscopic examination. RESULTS: Ischemia per se caused substantial damage. Restoration of volume and nutrients reversed this damage at 1 hour of reperfusion, but severe damage was evident at 4 hours of reperfusion, as reported by subjective and blinded examination. By using the new quantitative methods, there was a significant difference between the groups (P < .005) according to the time of post-ischemia-reperfusion, which correlated with the subjective evaluation of damage. CONCLUSIONS: These 2 new quantitative techniques provide an objective assessment of damage in the isolated rabbit lung model, suggesting that they warrant further consideration in similar studies of ischemia reperfusion injury.

Late outcomes of pediatric heart transplantation are independent of pre-transplant diagnosis and prior cardiac surgical intervention.

BACKGROUND: An increasing number of children are being referred for cardiac transplantation after (1) failing conventional corrective or palliative surgical reconstruction, (2) after stabilization with mechanical circulatory support devices, and (3) when primary graft failure or advanced cardiac allograft vasculopathy are established. METHODS: The records of 417 infants and children (age range, 0-18 years) who underwent cardiac transplantation from November 1985 through December 2005 at Loma Linda University Children's Hospital were retrospectively reviewed. The pre-transplantation diagnosis was used to divide patients into 3 groups: primary cardiomyopathy (CM), 103; hypoplastic left heart syndrome (HLHS), 154; and other complex congenital heart disease (CCHD), 160. These groups were compared and analyzed for differences in early and late morbidity and mortality. RESULTS: Operative mortality was significantly lower in the CM group compared with the HLHS (p < 0.02;) and CCHD groups (p < 0.01). Long-term actuarial recipient survival, however, was similar for all groups. The 15-year actuarial survival was 59% for the CM Group, 57% for the HLHS Group, and 50% for the CCHD Group. Actuarial survival after retransplantation is not statistically different from that with primary cardiac transplantation. CONCLUSION: Although peri-operative survival was lower in infants and children with HLHS and CCHD compared with those with CM, long-term survival has been the same for all groups. Late survival after retransplantation was not statistically different than among those with primary cardiac transplantation.

Atrial natriuretic peptide protects against ischemia-reperfusion injury in rabbit hearts in vivo.

The aim of this study is to investigate whether atrial natriuretic peptide can mimic preconditioning to protect ischemia or reperfusion injury in rabbit hearts. New Zealand white rabbits were randomized into 3 groups: (1) Controls. Hearts received a 60 minute-occlusion of the left anterior descending artery, followed by a 180 minute-reperfusion. (2) Preconditioning. Two 5-minute periods of ischemia separated by a 10-minute reperfusion, followed by a 60-minute ischemia and a 180-minute reperfusion. (3) Atrial natriuretic peptide treatment. Bolus injection of exogenous atrial natriuretic peptide (2.5 microg/kg) given intravenously at 15 minutes prior to 60 minute-ischemia followed by a 180-minute reperfusion. Myocardial necrotic area and area at risk of necrosis were determined by triphenyltetrazolium chloride staining. Ratio of necrotic area to area at risk was 49.95% +/- 1.15%, 7.95% +/- 0.33%, and 8.36% +/- 0.61% in the controls, preconditioning group, and atrial natriuretic peptide group, respectively. Both preconditioning and atrial natriuretic peptide significantly reduced the size of infarct caused by ischemia (preconditioning vs controls, P < .05; atrial natriuretic peptide vs controls, P < .05). Atrial natriuretic peptide can mimic ischemic preconditioning to protect rabbit hearts from prolonged ischemia and reperfusion injury. It may be involved in the cardioprotective mechanisms of preconditioning.