A Novel Case of Marfan Syndrome in an Infant With Hypoplastic Left Heart Syndrome

This report describes a case of hypoplastic left heart syndrome (HLHS) and Marfan syndrome presenting in conjunction, and highlights how a connective tissue disorder may alter medical and surgical management of newborns with HLHS.

Self-reported functional health status following interrupted aortic arch repair: A Congenital Heart Surgeons' Society Study

OBJECTIVES

Improved survival after congenital heart surgery has led to interest in functional health status. We sought to identify factors associated with self-reported functional health status in adolescents and young adults with repaired interrupted aortic arch.

METHODS

Follow-up of survivors (aged 13-24 years) from a 1987 to 1997 inception cohort of neonates included completion of functional health status questionnaires (Child Health Questionnaire-CF87 [age <18 years, n = 51] or the Short Form [SF]-36 [age ≥18 years, n = 66]) and another about 22q11 deletion syndrome (22q11DS) features (n = 141). Factors associated with functional health status domains were determined using multivariable linear regression analysis.

RESULTS

Domain scores of respondents were significantly greater than norms in 2 of 9 Child Health Questionnaire-CF87 and 4 of 10 SF-36 domains and only lower in the physical functioning domain of the SF-36. Factors most commonly associated with lower scores included those suggestive of 22q11DS (low calcium levels, recurrent childhood infections, genetic testing/diagnosis, abnormal facial features, hearing deficits), the presence of self-reported behavioral and mental health problems, and a greater number of procedures. Factors explained between 10% and 70% of domain score variability (R² = 0.10-0.70, adj-R² = 0.09-0.66). Of note, morphology and repair type had a minor contribution.

CONCLUSIONS

Morbidities associated with 22q11DS, psychosocial issues, and recurrent medical issues affect functional health status more than initial morphology and repair in this population. Nonetheless, these patients largely perceive themselves as better than their peers. This demonstrates the chronic nature of interrupted aortic arch and suggests the need for strategies to decrease reinterventions and for evaluation of mental health and genetic issues to manage associated deteriorations.

Quality of Life for Historic Cavopulmonary Shunt Survivors

BACKGROUND

Beginning with Dr William Glenn in 1958, 90 patients with congenital heart lesions underwent cavopulmonary (Glenn) shunts over a 30-year period. In 2015, the follow-up data on this original cohort were reported. The study focuses on the current quality of life of this cohort.

METHODS

Of the original 91 cavopulmonary shunt survivors, 14 (ages: 26-59; average length of postsurgical follow-up: 38.4 years) completed the Rand 36-Item Short-Form Health Survey, volume 2 (SF-36v2) quality-of-life survey at clinical office visits, over the phone or via regular mail. Diagnoses included tricuspid atresia (n = 9), double inlet left ventricle (n = 1), d-transposition of great arteries (n = 1), Ebstein's anomaly (n = 1), tetralogy of Fallot (n = 1), and pulmonary atresia with hypoplastic right ventricle (n = 1). Norm-based comparison of cavopulmonary shunt survivors to the general population was performed using a one-sample t test.

RESULTS

The 36-question health survey, SF-36v2, provided physical and mental health summary measures standardized to achieve a mean of 50. The 14 survivors' physical composite score was 47.18 (standard deviation [SD]: 8.24; P = .22) and mental composite score was 52.71 (SD: 5.64; P = .095).

CONCLUSION

The cavopulmonary shunt is now a widely used surgical palliation for single-ventricle patients and can be associated with physical and mental health outcomes similar to the general US population. Cavopulmonary shunt survivors' SF-36v2 survey results do not demonstrate a statistically significant difference from the general US population in physical or mental health measures. The results of this study contribute to the discussion of quality of life for patients with congenital heart disease by following up with the oldest known survivors.

Anomalous Origins of Coronary Arteries From the Pulmonary Artery: A Comprehensive Review of Literature and Surgical Options

Anomalous origins of coronary arteries from the pulmonary artery are rare malformations in which the coronary arteries originate from pulmonary artery sinuses or branches. The consequences are variable although, in most cases, these anomalies lead to severe coronary hypoperfusion and ventricular dysfunction. Surgical correction is indicated once the diagnosis is established due to high early mortality associated with the disease. In nearly all cases, the anomalous artery can be excised from its pulmonary origin, mobilized, and reimplanted directly into the ascending aorta using different surgical techniques. In rare circumstances, technical modifications must be used to restore a normal dual coronary perfusion. The emphasis of this article is to provide a collective review of surgical options published in the literature.

Persistent Pulmonary Hypertension in a Neonate With Transposition of Great Arteries and Intact Ventricular Septum

Transposition of the great arteries (TGA) with intact ventricular septum (IVS) has very favorable short- and long-term surgical outcome. Although rare, when associated with persistent pulmonary hypertension (PPH), it exhibits significant mortality risk and management challenges. We report the case of a neonate with TGA with IVS and PPH who underwent successful early surgical repair with emphasis on clinical management and review of the literature.

Repair of Anomalous Aortic Origin of a Coronary Artery in 113 Patients

Background:

Anomalous aortic origin of a coronary artery (AAOCA) encompasses a wide morphologic spectrum, which has impeded consensus regarding indications for the diverse repair strategies. We constructed a profile of current surgical techniques and explore their application to morphologic variants.

Methods:

Patients <30 years old (n = 113) with isolated AAOCA who underwent operations at 29 Congenital Heart Surgeons Society (CHSS) institutions from 1998 to 2012 were identified from the CHSS AAOCA Registry. Operative findings were related to surgical techniques at index repairs by cross-tabulation.

Results:

Anomalous origin of the left main or left anterior descending coronary artery was present in 33 (29%) patients and of the right coronary artery in 78 (69%) patients; 2 arteries originated directly above the commissure between the left and right sinuses. There were 101 (89%) interarterial and intramural (IA/IM) arteries, 10 (9%) were interarterial but not intramural (IA/NIM) and 2 (2%) were neither interarterial nor intramural. Intramural arteries were unroofed in 100 (88%) operations, usually with intimal tacking after incision (n = 47) or excision (n = 25) of the common wall. Coronary reimplantation (n = 11), pulmonary artery relocation (n = 7; 5 for IA/NIM), simple ostioplasty (without unroofing; n = 3), coronary artery bypass grafting (n = 2), and ostial window (n = 1) were less common. In 37 (33%) operations, a valvar commissure was taken down; 33 were resuspended.

Conclusion:

Current surgical repair of AAOCA is individualized to morphology, particularly the presence of intramural and/or interarterial segments. This report is foundational for future planned CHSS studies that will examine interventional and noninterventional outcomes and ultimately guide management of AAOCA.

Abstract 69: Diminished T-Tubule Density in Newborn Human Ventricular Cells Is Associated with Heterogeneity of Calcium Transients

For children with congenital heart disease (CHD), therapies developed for adults may have different effects on immature myocardium. Thus, it is critical to understand calcium handling in the young human ventricle.

Methods: Human ventricular cells were isolated from tissue removed as part of the surgical repair for CHDs from two age groups: newborns (<1 week old) and infants (2-12 months old). Developmental changes in t-tubules were examined in live cells with Di-8 ANEPPS which highlights the cell membrane. We measured the T-index (percent of cell interior occupied by t-tubules), averaged for at least 3 confocal z-sections per cell. Changes in calcium transients were measured by confocal line scans in cells loaded with Fluo-4 and field stimulated (37°C).

Results: Newborn human myocytes have very few t-tubules whereas infant myocytes have a range of t-tubule densities. The T-index in newborn myocytes was significantly less than in infant myocytes (4.4±0.2%, n=8 cells, 3 newborns vs. 9.1±0.9%, n=55 cells, 7 infants). Furthermore, there was sizable heterogeneity in the T-index for each patient in the infant group, in which some cells had few t-tubules and others had many t-tubules. We calculated the coefficient of variation (CV=SD/mean*100) for each patient and compared CV values for newborns vs. infants. CV was significantly greater in infants compared to newborns (46.5±7.4%, n=7, vs. 9.4±1.9%, n=3, p<0.02). In addition, calcium transients from newborn cells had a ‘U’ shaped wavefront with calcium first increasing at the outer edge of the cell then propagating toward the center. In contrast, infant cells had a homogenous calcium wavefront. The delay of peak calcium from the edge to center was significantly longer in newborns compared to infants (61.7±8.9 ms, n=8 cells, 3 newborns vs. 10.6±1.6 ms, n=6 cells, 4 infants, p<0.001).

Conclusions: There are heterogeneous calcium transients in newborn human myocytes that correspond to a lack of t-tubules. Furthermore, t-tubule development occurs in a heterogeneous manner throughout the first year of life with cells from the same patient exhibiting different degrees of t-tubule development. This is the first study to examine t-tubule development and calcium transients in the very young human ventricular myocardium.

Intermediate-term mortality and cardiac transplantation in infants with single-ventricle lesions: risk factors and their interaction with shunt type

OBJECTIVE

The study objective was to identify factors associated with death and cardiac transplantation in infants undergoing the Norwood procedure and to determine differences in associations that might favor the modified Blalock-Taussig shunt or a right ventricle-to-pulmonary artery shunt.

METHODS

We used competing risks methodology to analyze death without transplantation, cardiac transplantation, and survival without transplantation. Parametric time-to-event modeling and bootstrapping were used to identify independent predictors.

RESULTS

Data from 549 subjects (follow-up, 2.7 ± 0.9 years) were analyzed. Mortality risk was characterized by early and constant phases; transplant was characterized by only a constant phase. Early phase factors associated with death included lower socioeconomic status (P = .01), obstructed pulmonary venous return (P < .001), smaller ascending aorta (P = .02), and anatomic subtype. Constant phase factors associated with death included genetic syndrome (P < .001) and lower gestational age (P < .001). The right ventricle-to-pulmonary artery shunt demonstrated better survival in the 51% of subjects who were full term with aortic atresia (P < .001). The modified Blalock-Taussig shunt was better among the 4% of subjects who were preterm with a patent aortic valve (P = .003). Lower pre-Norwood right ventricular fractional area change, pre-Norwood surgery, and anatomy other than hypoplastic left heart syndrome were independently associated with transplantation (all P < .03), but shunt type was not (P = .43).

CONCLUSIONS

Independent risk factors for intermediate-term mortality include lower socioeconomic status, anatomy, genetic syndrome, and lower gestational age. Term infants with aortic atresia benefited from a right ventricle-to-pulmonary artery shunt, and preterm infants with a patent aortic valve benefited from a modified Blalock-Taussig shunt. Right ventricular function and anatomy, but not shunt type, were associated with transplantation.

Association of feeding modality with interstage mortality after single-ventricle palliation

OBJECTIVE

Interstage mortality has been reported in 10% to 25% of hospital survivors after single-ventricle palliation. The purpose of this study was to examine the impact of feeding modality at discharge after single-ventricle palliation on interstage mortality.

METHODS

We conducted a retrospective review of all neonates undergoing single-ventricle palliation from January 2003 to January 2010. A total of 334 patients (90%) survived to hospital discharge, comprising the study group. Preoperative, operative, and postoperative variables were examined, including feeding method at discharge. Multivariate Poisson regression models were constructed to estimate the relative risk of interstage mortality.

RESULTS

Of 334 patients, 56 (17%) underwent gastrostomy tube ± Nissen. There was a statistically significant increase in interstage mortality for patients who underwent gastrostomy tube ± Nissen compared with patients who did not (relative risk, 2.38; 95% confidence interval, 1.05-5.40; P = .04]). Of the 278 patients who were not fed via a gastrostomy tube ± Nissen, 190 (68%) were fed with nasogastric feedings and 88 (32%) were fed entirely by mouth. There was no difference in interstage mortality between these 2 groups (relative risk, 0.92; 95% confidence interval, 0.31-2.73; P = .89).

CONCLUSIONS

Neonates undergoing single-ventricle palliation who require gastrostomy tube ± Nissen are at an increased risk of interstage mortality. The need for gastrostomy tube ± Nissen in this population may be a marker for other unmeasured comorbidities that place them at an increased risk of interstage mortality. Discharge with nasogastric feeds does not increase the risk of interstage mortality.

Neurodevelopmental outcomes in children with Down syndrome and congenital heart defects

Trisomy 21, the chromosomal condition responsible for Down syndrome (DS, OMIM #190685), is the most common identifiable genetic cause of intellectual disability. Approximately half of all children with DS are born with a significant congenital heart defect (CHD), the most common of which is an atrioventricular septal defect (AVSD). As children with comorbid DS and CHD increasingly survive cardiac surgery, characterization of their early developmental trajectories is critical for designing early interventions to maximize individual potential. Herein, the developmental domains (cognitive, language, and motor) of children with DS and AVSD (DS + AVSD, n = 12) were compared to children with DS and a structurally normal heart (DS - CHD, n = 17) using the Bayley Scales of Infant and Toddler Development III. The DS + AVSD cohort mean age was relatively the same as controls with DS - CHD, 14.5 ± 7.3 months compared with 14.1 ± 8.4 months, respectively. Although the motor domain was the only domain that showed a statistically significant difference between groups (P < 0.05), both cognitive standard scores (P = 0.63) and language composite standard scores (P = 0.10) were lower in the DS + AVSD cases compared with the DS - CHD controls although it is not statistically significant. Since this is the first study to examine the early developmental outcomes of children with DS + AVSD, the findings may be useful for clinicians in providing anticipatory guidance.

Bloodstream infections increased after delayed sternal closure: cause or coincidence

BACKGROUND

Infants who undergo major cardiac operations are at risk for developing bloodstream infections which contribute to the morbidity, mortality, and cost of treatment. Determining what factors are associated with this increased risk of infection may aid in prevention. We sought to evaluate the practice of delayed sternal closure after neonatal cardiac surgery to determine its role as a risk factor for postoperative bloodstream infection.

METHODS

We reviewed 110 consecutive patients with hypoplastic left heart syndrome after stage 1 Norwood procedure at Children's Healthcare of Atlanta. The rates of bloodstream infections were determined and risks analyzed with regard to postoperative status of sternal closure; primary versus delayed.

RESULTS

Delayed sternal closure was utilized in 67 of 110 patients (61%), while 43 patients had primary sternal closure in the operating room. Overall rate of bloodstream infection was 22% (24 of 110), with 83% (20 of 24) of infections occurring in the delayed closure group. Among infants with delayed closure, 30% developed bloodstream infection, as compared with 9% of patients with primary closure (p = 0.017). Patients with delayed closure had a fourfold increased risk (odds ratio 3.9, p = 0.03) of developing bloodstream infection in-hospital. Predominant organisms were coagulase negative Staphylococcus species; there was one case of mediastinitis.

CONCLUSIONS

Delayed sternal closure is associated with an increased likelihood of bloodstream infection and should be recognized as a risk factor after neonatal cardiac operations.

Short-term outcomes in premature neonates adhering to the philosophy of supportive care allowing for weight gain and organ maturation prior to cardiac surgery

BACKGROUND

Prematurity is a recognized risk factor for morbidity and mortality following cardiac surgery. The purpose of this study was to examine short-term outcomes following cardiac surgery in premature neonates adhering to our institutional philosophy of supportive care allowing for weight gain and organ maturation.

METHODS

Retrospective review of all neonates undergoing cardiac surgery from January 2002 to May 2008. A total of 810 neonates (<30 days of age) were identified. Prematurity defined as less than 36 weeks of gestation. Neonates undergoing ductus arteriosus ligation alone were excluded. In all, 63 neonates comprised the premature group. Term group comprised 244 randomly selected term neonates in a 1:4 ratio. Outcome variables were compared between the 2 groups.

RESULTS

Median gestation 34 weeks, range 24 to 35 weeks. Defects: 2 ventricle, normal arch (41% premature vs 44% term; P = .7), 2 ventricle, abnormal arch (24% vs 22%; P = .8), single ventricle, normal arch (21% vs 15%; P = .2), single ventricle, abnormal arch (14% vs 19%; P = .4). Premature neonates were older and smaller at surgery. Cardiopulmonary bypass procedures were performed less frequently in premature neonates (49% vs 69%; P = .004). Length of mechanical ventilation at our institution (6 days [0.5-54) vs 4 days [0.5-49); P = .06); postoperative hospital stay at our institution (17 days [1-161) vs 15 days [0-153); P = .06); and mortality (16% vs 11%; P = .2) was not different between the 2 groups.

CONCLUSION

Early outcome seems independent of weight, prematurity, cardiopulmonary bypass, and type of first intervention. Importantly, there was no statistical difference in mortality between the 2 groups, regardless of how they were treated. Further long-term follow-up is needed in this patient population.

Early and delayed atrioventricular conduction block after routine surgery for congenital heart disease

OBJECTIVES

Patients undergoing surgical closure of ventricular septal defects are at risk for immediate or delayed atrioventricular conduction block. Our goal was to better define the incidence of delayed atrioventricular conduction block.

METHODS

A retrospective review was conducted of hospital records and pacemaker database for ventricular septal defect, atrioventricular canal, and tetralogy of Fallot repairs between 1999 and 2004. A total of 922 patients were identified (atrioventricular canal in 197, tetralogy of Fallot in 222, and ventricular septal defect in 503). Median follow-up was 4.1 years.

RESULTS

There were 472 male and 450 female patients, median age 6 months (0-444 months) and median weight 5.8 kg (1.3-116 kg) at surgery. Postoperative atrioventricular conduction block developed in 21 (2.3%) of the 922, being transient, with return of conduction 3 days (1-14 days) after surgery, in 13 (1.4%) and permanent, with pacemakers implanted 10 days (6-20 days) after surgery, in 8 (0.9%). Of the 905 patients at risk for delayed atrioventricular conduction block, 3 (0.3%) had second- or third-degree block at 2, 8, and 16 months after surgery. Two of these 3 had transient postoperative block. For isolated ventricular septal defects, the incidence was 1 (0.2%) of 496. There were 8 late deaths at 31 months (7-45 months) after surgery. Five had normal conduction at death, but for 3 patients the conduction status at death could not be determined. Including these 3 patients as possible cases of delayed atrioventricular block yields an incidence of 0.3% to 0.7%.

CONCLUSIONS

The incidence of early atrioventricular conduction block requiring a pacemaker was 0.9% and that of delayed atrioventricular conduction block was 0.3% to 0.7%. Transient atrioventricular conduction block may be a marker for increased risk of delayed block. These data may be useful for evaluation of new techniques.

Do neonates with genetic abnormalities have an increased morbidity and mortality following cardiac surgery?

INTRODUCTION

Genetic abnormalities occur in approximately 20% of children with congenital heart disease. The purpose of this study was to evaluate the effect of genetic abnormalities on short-term outcomes following neonatal cardiac surgery.

METHODS

Retrospective review of all neonates (n = 609) undergoing cardiac surgery from January 2003 to December 2006. Genetic abnormalities were identified in 93 neonates (15%). Genetic abnormalities identified were 22q11.2 deletion (23), chromosomal abnormalities including various monosomies, trisomies, deletions, duplications, and inversions (17), dysmorphic undefined syndrome without recognized chromosomal abnormality (27), Down syndrome (9), laterality sequences (9), recognixed syndromes and genetic etiology including Mendelian (i.e. Alagille, CHARGE) (8).

RESULTS

Neonates with genetic abnormalities had lower birth weights and were older at time of surgery. There was no difference in operative variables, duration of mechanical ventilation or ICU length of stay between the two groups. There was an increase in total hospital length of stay and postoperative complications in the neonates with genetic abnormalities. Importantly, in hospital mortality was not different.

CONCLUSION

Neonates with genetic abnormalities have a higher risk of postoperative complications and a longer hospital length of stay. However, there is no increase in hospital mortality. This information may aid in patient management decisions and parental counseling. Longer-term studies are needed for understanding the total impact of genetic abnormalities on neonates with congenital heart disease.

Force frequency relationship of the human ventricle increases during early postnatal development

Understanding developmental changes in contractility is critical to improving therapies for young cardiac patients. Isometric developed force was measured in human ventricular muscle strips from two age groups: newborns (<2 wk) and infants (3-14 mo) undergoing repair for congenital heart defects. Muscle strips were paced at several cycle lengths (CLs) to determine the force frequency response (FFR). Changes in Na/Ca exchanger (NCX), sarcoplasmic reticulum Ca-ATPase (SERCA), and phospholamban (PLB) were characterized. At CL 2000 ms, developed force was similar in the two groups. Decreasing CL increased developed force in the infant group to 131 +/- 8% (CL 1000 ms) and 157 +/- 18% (CL 500 ms) demonstrating a positive FFR. The FFR in the newborn group was flat. NCX mRNA and protein levels were significantly larger in the newborn than infant group whereas SERCA levels were unchanged. PLB mRNA levels and PLB/SERCA ratio increased with age. Immunostaining for NCX in isolated newborn cells showed peripheral staining. In infant cells, NCX was also found in T-tubules. SERCA staining was regular and striated in both groups. This study shows for the first time that the newborn human ventricle has a flat FFR, which increases with age and may be caused by developmental changes in calcium handling.

Hemodynamic Effects and Safety of Nesiritide in Neonates with Heart Failure

Objective: Evaluate effects and safety of nesiritide (Natrecor, Scios Inc) human B-type natriuretic peptide, in neonates with heart failure.

Methods: Seventeen neonates, not responding to conventional therapy, treated with nesiritide were retrospectively reviewed.

Results: Average age 16 + 8 days; weight 3.2 + 0.6 kg. Fifteen treated with concomitant inotropic therapy; all with diuretics. Twelve received loading dose; followed by continuous infusions of 0.005 mcg/kg/min (2); 0.01 mcg/kg/min (12); 0.02 mcg/kg/min (3). Length of therapy 5 + 4 days. No change in heart rate or blood pressure between baseline, 1 hour or 24 hours of nesiritide infusion. Decrease central venous pressure (CVP) 24 hours after infusion (p = 0.03). Ins-out ratio improved in 29%. No difference in pre and post therapy BUN and creatinine (Cr). 18% had hypotension requiring intervention.

Conclusions: Nesiritide use in neonates may improve hemodynamics as demonstrated by reduction in CVP. All patients tolerated bolus dosing, however, transient hypotension occurred in 18% of neonates with continuous infusion.

Feeding difficulty in newborns following congenital heart surgery

OBJECTIVE

Following neonatal congenital heart surgery, one of the factors impacting patient recovery is feeding difficulty. The aim of this study is to identify the risk factors.

METHODS

Patients who underwent surgery for congenital heart defects within the first 15 days of life were reviewed. Endpoints for feeding difficulty included: (1) a prolonged time to reach goal feeds; (2) a prolonged transition to oral feeds requiring tube feeds at discharge; and (3) additional procedures to facilitate feeding. Preoperative, operative, and postoperative data were examined to identify risk factors for feeding difficulty.

RESULTS

A total of 83 records were reviewed and showed the following feeding difficulties: 9 patients (10.8%) had a prolonged time to reach goal feeds, 37 (44.6%) had a prolonged time to transition to oral feeds, and 8 (9.6%) required subsequent procedures to facilitate feeding. Significant risk factors for all endpoints included an increased risk adjusted congenital heart surgery (RACHS) score and prolonged intubation. Significant risk factors for individual endpoints included return to the intensive care unit with an open chest for endpoint 1, and a single functional ventricle and the presence of a shunt for endpoint 3. The remaining factors (gestational age, weight at the time of surgery, being intubated at the time of surgery, underlying disease, utilization and time of cardiopulmonary bypass, utilization of trans-esophageal echocardiography, and surgical proximity to the aortic arch) had no significant effect on postoperative feeding.

CONCLUSIONS

Feeding difficulties are not uncommon following surgery for the correction of congenital heart defects, especially in the neonate. The most important risk factors appear to be an increased RACHS score and prolonged postoperative intubation. Hopefully, by defining the risk factors, proactive management strategies can be developed to minimize these problems following neonatal congenital heart surgery.

The endothelin-1 G5665T polymorphism impacts transplant-free survival for single ventricle patients

BACKGROUND

Early survival for children with single-ventricle congenital heart disease has improved, but late attrition remains a serious problem. The endothelin-1 G5665T single nucleotide polymorphism has been linked to increased vascular reactivity and hypertension. The goal of this study was to determine whether this single nucleotide polymorphism alters transplant-free survival for children with single-ventricle congenital heart disease.

METHODS

DNA was isolated from 165 children with single-ventricle congenital heart disease born between January 1980 and December 2006. The endothelin-1 G5665T single nucleotide polymorphism genotype was determined by using real-time polymerase chain reaction. Kaplan-Meier survival curves were generated with a combined end point of death or transplantation. The Cox proportional hazard method was used to evaluate potential covariates.

RESULTS

The endothelin-1 G5665T genotype was significantly associated with transplant-free survival for the group as a whole (P = .002), with the greatest effect in children with hypoplastic left heart syndrome (n = 64, P = .0002) as opposed to patients with other types of single-ventricle anatomy (n = 101, P = .1). Cox proportional hazard modeling revealed 3 independent predictors of poor outcome: endothelin G5665T genotype (T/T genotype, P = .001), prematurity (gestational age <37 weeks, P = .02), and era of surgical intervention (1990s vs other decades, P = .02).

CONCLUSIONS

Long-term survival of single-ventricle patients is dependent on many factors. These data suggest that genetic variability involving vascular resistance modifiers, such as endothelin-1, might play an important role, particularly in patients with hypoplastic left heart syndrome. Future studies should include evaluation of the relationship between endothelin genotype and plasma endothelin levels and possibly therapeutic trials of endothelin blockers in high-risk patients.

Risk adjustment for congenital heart surgery (RACHS): is it useful in a single-center series of newborns as a predictor of outcome in a high-risk population?

OBJECTIVE

Risk adjustment for congenital heart surgery (RACHS) was developed to compare outcome data for pediatric patients undergoing cardiac surgery. RACHS stratifies anatomic diversity into 6 categories based on age, type of surgery performed, and similar in-hospital mortality. The purpose of this retrospective review was to evaluate the use of RACHS in a single-center series as a predictor of outcome in a high-risk newborn population.

METHODS

In 2003, 793 pediatric cardiac surgical operations (584 open; 209 closed) were performed at our institution. Mortality was 2.1%. Of the 793 operations, 114 were in newborns less than 15 days of age. These 114 newborns were stratified according to RACHS. Two patients could not be stratified and were excluded from analysis. Preoperative, operative, and postoperative variables were compared between the RACHS stratified newborns.

RESULTS

Unexpectedly, newborns in RACHS category 4 had lower birth weights (3.0 +/- 0.5 kg vs. 3.5 +/- 0.5 kg; P < .05) and a trend toward increased postoperative inotropic score (19 +/- 7 vs. 16 +/- 4), increased postoperative lactic acid (72 +/- 48 vs. 63 +/- 25), increased length of mechanical ventilation (23 +/- 72 days vs. 8 +/- 6 days), increased length of stay (34 +/- 72 days vs. 31 +/- 17 days), and increased mortality (16% vs. 11%) compared with newborns in RACHS category 6.

CONCLUSION

Limitations of risk assessment using RACHS in a single-center series of high-risk newborns include the lack of consideration of confounding variables. Further risk adjustments that include such confounding variables are warranted.

Pre-hospital discharge car safety seat testing in infants following congenital heart surgery

The purpose of this study was to expand the American Academy of Pediatrics' (AAP) car safety seat testing recommendation to include high-risk infants following cardiac surgery. Car safety seat testing (< or =4 days prior to discharge) was retrospectively reviewed for 66 postoperative infants. Car safety seat testing was performed according to AAP guidelines. Failure of the test was defined as the occurrence of apnea, bradycardia, or oxygen desaturation. Average birth weight was 3.1 +/- 0.5 kg. Two patients were born <37 weeks of gestation. Surgical procedures included modified Blalock-Taussig shunt (15), arterial switch operation (12), Norwood-Sano modification (11), coarctation repair (8), repair of tetralogy of Fallot (6), repair of truncus arteriosus (4), repair of total anomalous pulmonary venous return (3), pacemaker (2), repair of interrupted aortic arch and ventricular septal defect (VSD) (1), repair of coarctation/VSD (1), orthotopic heart transplant (1), repair of VSD (1), and patent ductus arteriosus ligation (1). Average age at discharge was 28 +/- 21 days. Four patients (6%) failed car safety seat testing secondary to a decrease in oxygen saturation. One of four passed on retesting after parental education; three of 4 (75%) were discharged home in a supine car safety seat. There was no relationship between the type of surgery and car safety seat test failure. It may be beneficial to extend the AAP recommendations for car safety seat testing to include this high-risk patient population.

Prehospital discharge car safety seat testing of infants after congenital heart surgery

BACKGROUND

This study aimed to expand the American Academy of Pediatrics (AAP) car safety seat testing recommendation to include high-risk infants after cardiac surgery.

METHODS

Car safety seat testing (< or =4 days before discharge), performed according to AAP guidelines, was retrospectively reviewed for 66 postoperative infants. Failure was defined as apnea, bradycardia, or oxygen desaturation.

RESULTS

The average birth weight of the study infants was 3.1 +/- 0.5 kg. Two patients were born at less than 37 weeks gestation. Surgical procedures included modified Blalock-Taussig shunt technique (n = 15), arterial switch operation (n = 12), Norwood Sano modification (n = 11), coarctation repair (n = 8), repair of tetralogy of Fallot (n = 6), repair of truncus arteriosus (n = 4), repair of total anomalous pulmonary venous return (n = 3), pacemaker placement (n = 2), repair of interrupted aortic arch and ventriculoseptal defect (VSD) (n = 1), repair of coarctation and VSD (n = 1), orthotopic heart transplant (n = 1), repair of VSD (n = 1), and patent ductus arteriosus ligation (n = 1). The average age at discharge was 28 +/- 21 days. Four patients (6%) failed car safety seat testing because of a fall in oxygen saturation. One of the four patients passed on retesting after parental education, whereas three of the four (75%) were discharged home in a supine car safety seat. There was no relationship between the type of surgery and car safety seat test failure.

CONCLUSION

It may be beneficial to extend the AAP recommendations for car safety seat testing to include high-risk infants after cardiac surgery.

Routine Immunizations and Adverse Events in Infants With Single-Ventricle Physiology

BACKGROUND

Infants with single-ventricle congenital heart defects are at risk of sudden unexpected death. In an effort to decrease the risk of sudden death, some centers have advocated that routine immunizations be deferred in this population. However, it is not known if an association exists between immunizations and adverse events.

METHODS

The present study examined the relationship of routine immunizations with adverse events, which were defined as sudden death or hospital readmission. The diphtheria-tetanus-acellular pertussis (DTaP) vaccine was considered in the analysis. The patient population consisted of infants younger than 9 months old who resided locally and had not yet undergone bidirectional cavopulmonary anastomosis (BCPA). Immunization data were obtained from a mandatory statewide database.

RESULTS

During a 35-month period, 137 patients with single-ventricle physiology were discharged home after neonatal surgery or directly from the newborn nursery. Hypoplastic left heart syndrome (HLHS) was the diagnosis in 58 patients (42%) and was the most common. In the entire cohort, there were four sudden deaths (3%), and 53 patients (38%) had at least one interval hospital admission. Immunization within 48 hours was not associated with adverse events (odds ratio, 1.48; 95% confidence interval, 0.73 to 2.90; p = 0.31). No sudden death events occurred within 48 hours of immunization.

CONCLUSIONS

No association could be identified between routine immunizations and adverse events in infants with single-ventricle physiology. As such, the proposal to alter the immunization regimen in this population does not appear justified.

What is the Optimal Management of Infants With Coarctation and Ventricular Septal Defect?

BACKGROUND

The management of patients with aortic coarctation and ventricular septal defect (VSD) remains controversial. We reviewed our experience with coarctation and VSD from 2002 to 2006.

METHODS

Three approaches were used to manage 36 consecutive infants with coarctation and VSD. Group I had staged coarctation repair with or without pulmonary artery banding, followed by VSD closure with two separate operations (two-stage, n = 11); Group II had coarctation repair and VSD closure on cardiopulmonary bypass (CPB) with circulatory arrest or regional perfusion during coarctation repair (one-stage, one-incision, n = 10); Group III had coarctation repair without CPB through a thoracotomy, followed by VSD closure during the same operation (one-stage, two-incisions, n = 15).

RESULTS

No patients died. One recoarctation occurred in group II. Group II had significantly longer times for CPB (135.6 +/- 31.8 versus 94.3 +/- 29.8 minutes for group I; 67.6 +/- 16.7 minutes for group III; p < 0.001) and combined regional perfusion/circulatory arrest (30.0 +/- 17.0 versus 5.3 +/- 11.9 minutes for group I, 1.1 +/- 4.4 minutes for group III, p < 0.0001). Group III compared with group II had significantly shorter lengths of stay in the intensive care unit (119.5 +/- 64.8 versus 220.8 +/- 198.8 hours, p = 0.04) and hospital (8.4 +/- 3.8 versus 24.4 +/- 24.4 days, p = 0.01). Combining values for the two hospitalizations in the group I infants, lengths of stay in the intensive care unit (178.8 +/- 70.8 hours) and hospital (20.5 +/- 11.6 days) were intermediate between groups II and III.

CONCLUSIONS

Primary repair of infants with coarctation and VSD using a one-stage approach through separate incisions affords excellent clinical results. One can avoid prolonged aortic cross-clamping, CPB, and circulatory arrest/regional perfusion. Compared with the group undergoing combined coarctation and VSD repair simultaneously by sternotomy, total lengths of stay in the intensive care unit and hospital were significantly decreased.

What is the optimal time to repair atrioventricular septal defect and common atrioventricular valvar orifice?

OBJECTIVE

With improvements in technology and surgical technique, paediatric cardiologists are challenging surgeons to repair balanced atrioventricular septal defects in smaller patients. Early repair minimizes aggressive medical therapy to prevent heart failure, maintains growth, and limits exposure to elevated pulmonary pressures. We compare the outcomes of repair among different-sized children.

METHODS

From December 2002 to July 2005, 92 patients underwent repair of an atrioventricular septal defect with common atrioventricular valvar orifice and balanced ventricles. We reviewed operative and postoperative data. We excluded patients weighing more than 10 kilograms, but included those who underwent concomitant closure of a patent oval foramen or atrial septal defect, or ligation of a patent arterial duct. Those requiring other concomitant procedures were excluded from the analysis.

RESULTS

The median weight at repair was 4.9 kilograms, with a range from 2.93 to 7.9 kilograms, and the median age was 5.1 months, with a range from 0.39 to 9.6 months. Operative data included the time required for cardiopulmonary bypass, aortic cross-clamping, and the overall procedure. These times were not significantly affected by decreasing weight. Postoperative continuous data included duration of ventilation and length of intensive care unit and hospital stay. Stay in intensive care (p = 0.006) and hospital (p = 0.007) both increased significantly with decreasing weight. Postoperative categorical data included presence of residual ventricular septal defects, regurgitation across the left atrioventricular valve, and complications. While there was no difference in residual defects (p = 0.166) or valvar regurgitation (p = 0.729), there was a significantly higher presence of complications with decreasing weight (p = 0.0043). There was no mortality, and no persistent heart block requiring placement of a permanent pacemaker.

CONCLUSIONS

Our data shows that, with the exception of a slightly longer and more complicated postoperative course, early surgery for symptomatic patients with atrioventricular septal defects and common atrioventricular valvar orifice can be undertaken safely and effectively in smaller children with excellent outcomes.

Late cardiopulmonary and musculoskeletal exercise performance after repair for total anomalous pulmonary venous connection during infancy

OBJECTIVES

We evaluated cardiopulmonary function at rest and during exercise in children after surgical repair for total anomalous pulmonary venous connection.

BACKGROUND

Long-term assessment of cardiopulmonary function during exercise in children after repair for total anomalous pulmonary venous connection during infancy is limited.

METHODS

Resting lung function and cardiopulmonary function during maximal ramp cycle ergometry were evaluated in 27 patients (age = 11 +/- 4 years, 20 were male). Peak oxygen consumption, ventilatory anaerobic threshold, and physical working capacity were compared with normal reference values. Neurologic assessment included neuromuscular function, inattentiveness, and hyperactivity. Patient- and procedure-related variables were assessed for association with peak oxygen consumption, ventilatory anaerobic threshold, and physical working capacity.

RESULTS

Compared with healthy children, peak oxygen consumption (88% +/- 16% of predicted) and ventilatory anaerobic threshold (91% +/- 21% of predicted) were mildly reduced. Chronotropic impairment was observed in 7 patients (32%). Patients with impaired resting lung mechanics were more likely to have impairment in peak oxygen consumption (P < .05). Breathing reserve was normal. Specific anatomy and all operative factors did not have a significant impact on overall exercise performance. Composite score for fine and gross motor function was associated with lower ventilatory anaerobic threshold (P < .05).

CONCLUSIONS

Exercise performance is mildly impaired at long-term follow-up after total anomalous pulmonary venous connection repair during infancy. Residual pulmonary abnormalities are common and associated with lower exercise performance. Neurologic abnormalities are evident in a subgroup, but the impact on late exercise performance is inconclusive.

Does preoperative mechanical ventilation affect outcomes in neonates undergoing cardiac surgery?

OBJECTIVE

To review, in retrospective fashion, the effect of preoperative mechanical ventilation on neonatal outcomes after cardiac surgery.

METHODS

We studied 114 newborns less than 15 days old admitted to the cardiac intensive care unit for cardiac surgery. Of the newborns, 71 (62%) were mechanically ventilated at the referring hospital before transport to our institution. Of the 71 ventilated patients, 14 were extubated and breathing spontaneously before cardiac surgery. We compared variable haemodynamics and outcomes between the 57 patients mechanically ventilated at time of cardiac surgery, and the 57 patients breathing spontaneously at this time.

RESULTS

Newborns mechanically ventilated before cardiac surgery had increased preoperative haemodynamic compromise, increased postoperative sepsis (p equal to 0.02) and mortality (p equal to 0.005) compared with those breathing spontaneously before cardiac surgery.

CONCLUSION

Newborns requiring preoperative mechanical ventilation had greater risk of postoperative morbidity and mortality. Heightened vigilance is warranted in this population of patients at high risk.

Long-term noninvasive arrhythmia assessment after total anomalous pulmonary venous connection repair

BACKGROUND

Pediatric patients with a history of atrial surgery are at risk for the development of sinus node dysfunction and atrial arrhythmias. However, there has been no comprehensive, long-term, electrophysiologic study of patients who have undergone repair of total anomalous pulmonary venous connection.

METHODS

We evaluated school-aged and adolescent survivors of isolated total anomalous pulmonary venous connection repair from January 1983 to December 1996 to assess for sinus node dysfunction, atrioventricular block, and atrial and ventricular arrhythmias. Assessment was limited to an electrocardiogram, 24-hour Holter monitor, and exercise stress test.

RESULTS

Twenty-nine children were evaluated 11.2 +/- 3.6 years after their initial operative repair. The mean age at repair was 36.0 +/- 43.0 days. Electrophysiologic studies revealed evidence of sinus node dysfunction, including sinus bradycardia, sinus pauses, and chronotropic impairment, in most of the patients. Twenty-nine percent of patients showed chronotropic impairment on exercise testing. Atrioventricular conduction abnormalities occurred in 2 patients. Single atrial and ventricular premature complexes were frequent, but complex tachyarrhythmias were less common. There was 1 patient who had nonsustained supraventricular tachycardia and 2 patients who had nonsustained ventricular tachycardia. No statistically significant relationships were found between hypothesized variables and arrhythmia outcomes.

CONCLUSIONS

Survivors of total anomalous pulmonary venous connection repair appear to have a high incidence of signs of sinus node dysfunction and a low incidence of atrioventricular block in follow-up. Significant atrial and ventricular arrhythmias appear to be uncommon. Despite a favorable overall long-term outcome, these patients warrant ongoing clinical follow-up for arrhythmia surveillance.

Cerebral near infrared spectroscopy is a reliable marker of systemic perfusion in awake single ventricle children

Clinical assessment of systemic perfusion in single ventricle patients with parallel circulation can be difficult in the outpatient setting. Near infrared spectroscopy (NIRS) is a noninvasive measure of cerebral oximetry. We measured vital signs, pulse oximetry, and NIRS in 20 single ventricle patients with parallel circulation prior to routine cardiac catheterization. These variables were evaluated to determine the best noninvasive predictor of the superior vena cava saturation (SVC(sat)) as a marker for the adequacy of systemic oxygen delivery. The mean age was 6.7 months [standard deviation (SD), 8.6] and mean weight was 6.5 kg (SD, 2.2). Diagnoses were hypoplastic left heart syndrome (8), tricuspid or pulmonary atresia (10), and double-outlet right ventricle variants (2), all prior to cavo pulmonary anastomoses or complete repairs. Stepwise multiple regression analysis generated a model in which only NIRS was a significant independent predictor of SVC(sat) (p = 0.009). These results support the conclusion that NIRS can be a useful tool to evaluate awake single ventricle patients in the outpatient setting.

Redo Aortic Valve Replacement in Children

BACKGROUND

Some children who have had an aortic valve replacement (AVR) will need valve re-replacement (redo-AVR). We analyzed our results with 38 redo-AVRs in 30 children.

METHODS

Thirty children, aged 2 months to 20 years (mean, 11.5 +/- 5.4 years), underwent 38 redo-AVRs 1 month to 14 years (mean, 4.6 +/- 4.5 years) after previous AVR. Seven children had a second redo-AVR and one had a third redo-AVR (his fourth AVR). Reoperation indication was primarily stenosis in 19, regurgitation in 12, endocarditis in 3, valve thrombosis-emboli in 3, and ruptured aortic aneurysm in 1. The initial valve was mechanical in 26, homograft in 7, xenograft in 4, or a Ross procedure in 1. Sixteen patients (42%) had a previous Konno procedure.

RESULTS

The new valve was mechanical (28), homograft (5), xenograft (4), or a Ross procedure (1). Twenty-five valves were upsized on re-replacement. The median valve size was 23 mm (median size increase 4 mm). Twenty-seven operations (71%) included annulus enlargement (16 redo-Konno, 8 new Konno, and 3 Manougian). Twelve children (32%) had concomitant operations including mitral valve repair-replacement (4) and right ventricular outflow tract procedure (5). Three of the 4 hospital deaths were with second or third time redo-AVR. The only death in patients with first time redo-AVR was a patient in cardiogenic shock at the time of operation.

CONCLUSIONS

Redo-AVR in children can be performed with reasonable morbidity and mortality. A larger prosthesis can often be placed in these children. Second or third time redo-AVR appears to be riskier. Earlier referral before onset of ventricular dysfunction is warranted.

Failure of surface-modified bypass circuits to improve platelet function during pediatric cardiac surgery

OBJECTIVE

Surface-modified cardiopulmonary bypass circuits have been shown to improve platelet function and decrease postoperative bleeding after heart surgery in adults. Two surface-modified cardiopulmonary bypass circuits are approved and commercially available for pediatric cardiac surgery. There have been few studies demonstrating the efficacy of these modifications for children. We performed a prospective, randomized trial comparing surface-modified cardiopulmonary bypass circuits to a standard unmodified circuit in pediatric cardiac surgery.

METHODS

Sixty-nine children (median 6 months old) undergoing first-time cardiac surgery were enrolled and randomized to an uncoated circuit or one of the two commercially available surface modified circuits for their operation. Blood samples were collected at baseline, on cardiopulmonary bypass, at the end of rewarming, after protamine, and at 18 to 24 postoperative hours. Platelet count, beta-thromboglobulin, and thromboelastography with and without abciximab were measured. Postoperative chest tube outputs and blood product utilization were also analyzed.

RESULTS

The platelet counts, beta-thromboglobulin levels, thromboelastographic measures of platelet function, and postoperative bleeding were not significantly different between the surface-modified cardiopulmonary bypass circuit groups and the control group.

CONCLUSION

Currently available surface-modified cardiopulmonary bypass circuits do not significantly improve platelet function or clinical outcomes after routine pediatric cardiac surgery.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) in pediatric cardiac support

BACKGROUND

Resuscitation extracorporeal membrane oxygenation (R-ECMO) was introduced at our institution in July 2002. We reviewed the use of venoarterial (VA)-ECMO for cardiac diagnoses at our institution.

METHODS

Retrospective analysis of patients on VA-ECMO for cardiac failure was performed. Survival was defined as discharge from hospital.

RESULTS

Twenty-seven patients were supported with VA-ECMO (median age, 27 days; range, 1 to 640 days; median weight, 3.8 kg; range, 1.8 to 11.3 kg). Diagnoses were cardiomyopathy-myocarditis (CMM) in 8 (30%), systemic-to-pulmonary artery shunt-dependent single ventricle (SV) in 12 (44%), postcardiotomy for biventricular repair (BiV) in 6 (22%), and arrhythmia in 1 (4%). Sixteen of 27 patients survived (59%). Seven of 8 CMM patients survived (88%); 6 (75%) bridged to cardiac recovery, 1 to transplant (13%), and 1 death (13%). Seven of 12 SV patients survived (58%). The SV ECMO indications: post-Norwood ventricular dysfunction (n = 3, 2 deaths), postoperative cardiac failure (n = 6, 2 deaths), respiratory failure (n = 1, 1 death), and acute shunt occlusion (n = 2, 0 deaths). One of 6 BiV patients survived (17%). The BiV ECMO indications: failure to wean from CPB (n = 3, 3 deaths), postoperative cardiac failure (n = 2, 2 deaths), and pulmonary hypertension (n = 1, 0 deaths). Fifteen patients (56%) underwent cardiopulmonary resuscitation during ECMO cannulation. Eleven of 15 R-ECMO patients (73%) survived versus 5 of 12 non-R-ECMO patients (42%, p = 0.13). Median duration of R-ECMO: 66 hours (range, 18 to 179) versus 145 hours (range, 43 to 986, p = 0.01) for non-R-ECMO.

CONCLUSIONS

Resuscitation extracorporeal membrane oxygenation is an appropriate application in pediatric patients with cardiac disease. Single ventricle patients experiencing cardiopulmonary collapse and CMM patients have favorable outcomes. Failure to wean from CPB and postoperative ventricular failure are higher risk indications.

Cobalt Chloride Pretreatment Attenuates Myocardial Apoptosis After Hypothermic Circulatory Arrest

BACKGROUND

Deep hypothermic circulatory arrest (DHCA) causes myocyte injury as a consequence of ischemia and reperfusion. Previous studies have shown that hypoxia or hypoxia-mimetic agents (cobalt chloride [CoCl2] or deferoxamine [DFX]) limit myocyte necrosis by upregulating the transcription factor hypoxia-inducible factor. However, it remains unknown whether these agents attenuate myocardial apoptosis after DHCA. This study tested the hypotheses (1) that hypoxia, DFX, or CoCl2 preconditioning attenuates myocardial apoptosis during DHCA; and (2) that the protective mechanism involves the altered expression of apoptosis regulatory proteins pAkt (antiapoptotic), Bcl-2 (antiapoptotic), and Bax (proapoptotic).

METHODS

Anesthetized neonatal piglets were randomly assigned to four groups (n = 6 in a group): control (NaCl injection); hypoxia (pO2 of 30 to 40 mm Hg for 3 hours); DFX injection; or CoCl2 injection. Twenty-four hours later, the animals underwent cardiopulmonary bypass (CPB) and 110 minutes of DHCA. One week after CPB, percentage of apoptotic myocytes (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling [TUNEL] assay) and expression of the pAKT, Bcl-2, and Bax were assessed by Western blot.

RESULTS

Although preconditioning with hypoxia and DFX failed to show a protective benefit, CoCl2 pretreatment significantly attenuated myocardial apoptosis (9.3% +/- 4.1%) versus controls (33.8% +/- 9.7%, p = 0.042). That was associated with increased myocardial pAkt expression (0.19 +/- 0.006 in CoCl2 versus 0.12 +/- 0.008 in control, p < 0.001). The expression of Bcl-2 was also significantly higher in the CoCl2 group (0.15 +/- 0.02) versus control (0.11 +/- 0.01, p = 0.007), whereas Bax expression was lower (0.34 +/- 0.04 versus 0.54 +/- 0.03 for control, p < 0.001).

CONCLUSIONS

Preconditioning with CoCl2 before prolonged DHCA in neonatal piglets attenuates myocardial apoptosis by mechanisms involving phosphorylation of Akt, upregulation of the antiapoptotic protein Bcl-2, and decreased expression of the proapoptotic protein Bax.

Upregulation of hypoxia inducible factor is associated with attenuation of neuronal injury in neonatal piglets undergoing deep hypothermic circulatory arrest

BACKGROUND

Prolonged deep hypothermic circulatory arrest is known to cause neurological injury. Hypoxia inducible factor, a transcription factor that mediates adaptive changes during hypoxia, is neuroprotective in models of ischemic brain injury, in part by upregulating erythropoietin. This study tested the hypothesis that upregulation of hypoxia inducible factor and erythropoietin by preconditioning with hypoxia or the hypoxia-mimetic agents deferoxamine and cobalt chloride would be neuroprotective in a piglet model of deep hypothermic circulatory arrest.

METHODS

Anesthetized neonatal piglets were randomized to 4 preconditioning groups (15 per group): hypoxia, deferoxamine, cobalt chloride, or control (NaCl vehicle). Brain hypoxia inducible factor and erythropoietin contents were assessed by means of Western blotting at 3, 8, and 24 hours after treatment (n = 3 per time point). Twenty-four hours after treatment, 6 to 7 animals per group underwent cardiopulmonary bypass and 110 minutes of deep hypothermic circulatory arrest. After recovery, serial neurobehavioral examinations were conducted for 6 days, after which histopathologic brain injury and neuronal apoptosis (cleaved caspase 3) were assessed.

RESULTS

Erythropoietin expression was not significantly increased by any of the pretreatment strategies. In contrast, there was a significant upregulation of hypoxia inducible factor by pretreatment with deferoxamine and cobalt chloride (P = .002). Neurobehavioral measures revealed no significant differences in time to recovery or extent of injury. Examination of histopathologic brain injury in the hippocampus revealed that pretreatment with deferoxamine (0.4 +/- 0.3) and cobalt chloride (0.5 +/- 0.3) were associated with significantly less neuronal loss than pretreatment with hypoxia or control (2.8 +/- 0.5, P = .004). Finally, cleaved caspase 3 (a marker of apoptotic cell death) was also shown to be diminished in the cobalt and deferoxamine groups, but the difference was not significantly different from the value in the control group.

CONCLUSIONS

In contrast to hypoxia, deferoxamine and cobalt chloride preconditioning upregulated hypoxia inducible factor and were associated with histopathologic neuroprotection after exposure to cardiopulmonary bypass and prolonged deep hypothermic circulatory arrest.

Nesiritide in infants and children with congestive heart failure

OBJECTIVES

Nesiritide (synthetic B-type natriuretic peptide) has been shown to be effective in the management of acute decompensated heart failure in adults. The role of nesiritide in pediatric heart failure has not been examined. In the present study, we reviewed our initial experience with nesiritide in children with primary heart failure or low cardiac output after heart surgery.

METHODS

Nesiritide was administered in an open-label fashion to patients with heart failure who were already receiving inotropic and diuretic therapy. Between July 2003 and August 2004, 30 patients aged 5 days to 16.7 yrs (median age, 4.6 months) received nesiritide therapy. Diagnoses included single-ventricle congenital defect (n = 5), two-ventricle congenital defect (n = 13), heart transplant (n = 5), and dilated cardiomyopathy (n = 7). Sixteen patients were started on nesiritide within 2 wks of corrective or palliative heart surgery. The majority of subjects (n = 24) received an initial bolus dose. Continuous infusion dosage ranged between 0.005 and 0.02 microg.kg.min. Nesiritide was discontinued for possible side effects in two patients (arrhythmia and hypotension). Duration of therapy ranged from 1 to 24 days (median, 4 days).

RESULTS

Administration of nesiritide was associated with improvement in fluid balance from positive 0.8 +/- 1.9 mL.kg.hr at baseline to negative 0.3 +/- 1.8 mL.kg.hr after 24 hrs of therapy (p = .02). There was a nonsignificant trend toward a reduction in right atrial pressure (9.2 +/- 3.9 vs. 11.2 +/- 4.1, p = .08).

CONCLUSIONS

Nesiritide is well tolerated in children with heart failure and is associated with improved diuresis. Further prospective studies will be needed to compare nesiritide with other vasoactive agents and examine the cost-efficacy of this therapy.