Cardiopulmonary Bypass in Premature and Low Birth Weight Neonates - Implications for Postoperative Care From a Neonatologist/Intensivist Perspective

Use of Hybrid Stage I to Stratify Between Single Ventricle Palliation and Biventricular Repair

Background: Hybrid stage I palliation (HS1P) has been utilized for patients with single ventricle (SV) congenital heart disease (CHD). To date, reports on the use of HS1P for other indications including biventricular (BiV) CHD have been limited. Methods: We performed a single-center retrospective cohort study of patients who underwent HS1P with an anticipated physiologic outcome of BiV repair, or with an undetermined SV versus BiV outcome. Patient characteristics and outcomes from birth through definitive repair or palliation were collected and reported with descriptive statistics. Results: Nineteen patients underwent HS1P with anticipated BiV repair. Extracardiac and intracardiac risk factors (ICRF) were common. Ultimately, 13 (68%) patients underwent BiV repair, 1 (5%) underwent SV palliation, and 5 (26%) died prior to further palliation or repair. Resolution of ICRF tracked with BiV outcome (6/6, 100%), persistence of ICRF tracked with SV outcome or death (3/3, 100%). Twenty patients underwent HS1P with an undetermined outcome. Ultimately, 13 (65%) underwent BiV repair, 6 (30%) underwent SV palliation, and 1 (5%) underwent transplant. There were no deaths. Intracardiac risk factors were present in 15 of 20 patients (75%); BiV repair only occurred when all ICRF resolved (67%). Post-HS1P complications and reinterventions occurred frequently in both groups, through all phases of care. Conclusions: Hybrid stage 1 palliation can be used to defer BiV repair and to delay decision between SV palliation and BiV repair. Resolution of ICRF was associated with ultimate outcome. In this high-risk group, complications are common, and mortality especially in the marginal BiV patient is high.

Comparison of Three Different Multiple Organ Dysfunction Scores for Predicting Mortality after Neonatal Cardiac Surgery

Infants who undergo cardiac surgery frequently have complications that may advance to multiple organ failure and result in mortality. This study aims to compare three different multiple organ dysfunction scoring systems: the Neonatal Multiple Organ Dysfunction (NEOMOD) score, the modified NEOMOD score, and the Pediatric Logistic Organ Dysfunction-2 (PELOD-2) score in predicting postoperative 30-day mortality in neonates undergoing cardiac surgery. This retrospective cohort study was conducted between January 2019 and February 2021 in a single unit on neonates operated on due to congenital heart disease in the first 28 days of life. Patients who underwent off-pump surgeries were excluded from the study. The NEOMOD, modified NEOMOD, and PELOD-2 scores were calculated for each of the first 3 days following surgery. A total of 138 patients were included. All scores had satisfactory goodness-of-fit and at least good discriminative ability on each day. The modified NEOMOD score consistently demonstrated the best prediction among these three scores after the first day, reaching its peak performance on day 2 (area under curve: 0.824, CI: 0.75-0.89). Our findings suggest that NEOMOD and modified NEOMOD scores in the first 72 h could potentially serve as a predictor of mortality in this population.

Congenital heart disease: addressing the need for novel lower-risk percutaneous interventional strategies

INTRODUCTION

With the advent of improved neonatal care, increasingly vulnerable higher-risk patients with complex congenital heart anomalies are presenting for intervention. This group of patients will always have a higher risk of an adverse event during a procedure but by recognising this risk and with the introduction risk scoring systems and thus the development of novel lower risk procedures, the rate of adverse events can be reduced.

AREA COVERED

This article reviews risk scoring systems for congenital catheterization and demonstrates how they can be used to reduce the rate of adverse events. Then novel low risk strategies are discussed for low weight infants e.g. patent ductus arteriosus (PDA) stent insertion; premature infants e.g. PDA device closure; and transcatheter pulmonary valve replacement. Finally, how risk is assessed and managed within the inherent bias of an institution is discussed.

EXPERT OPINION

There has been a remarkable improvement in the rate of adverse events in congenital cardiac interventions but now, as the benchmark of mortality rate is switched to morbidity and quality of life, continued innovation into lower risk strategies and understanding inherent bias when assessing risk will be key to continuing this improvement.

Prematurity and Congenital Heart Disease: A Contemporary Review

Congenital heart disease (CHD) is the most commonly reported birth defect in newborns. Neonates with CHD are more likely to be born prematurely, and a higher proportion of preterm neonates have CHD than their term counterparts. The implications of preterm birth on the cardiac and noncardiac organ systems are vast and require special management considerations. The feasibility of surgical interventions in preterm neonates is frequently limited by patient size and delicacy of immature cardiac tissues. Thus, special care must be taken when considering the appropriate timing and type of cardiac intervention. Despite improvements in neonatal cardiac surgical outcomes, preterm and early term gestational ages and low birthweight remain important risk factors for in-hospital mortality. Understanding the risks of early delivery of neonates with prenatally diagnosed CHD may help guide perioperative management in neonates who are born preterm. In this review, we will describe the risks and benefits of early delivery, postnatal cardiac and noncardiac evaluation and management, surgical considerations, overall outcomes, and future directions regarding optimization of perinatal evaluation and management of fetuses and preterm and early term neonates with CHD.

Right ventricular outflow tract anomalies: Neonatal interventions and outcomes

Right ventricular outflow tract (RVOT) anomalies comprise a wide spectrum of congenital heart disease, typically characterized by obstruction to flow from the right ventricle to pulmonary arteries. This review highlights important considerations surrounding management strategy as well as clinical outcomes for the neonate with RVOT anomaly, including: pulmonary atresia with intact ventricular septum, congenital pulmonary valve stenosis, tetralogy of Fallot, and Ebstein anomaly with anatomic or physiologic RVOT obstruction.

Outcomes after neonatal cardiac surgery: The impact of a dedicated neonatal cardiac program

OBJECTIVES

Prematurity is a risk factor for in-hospital mortality after cardiac surgery. The structure of intensive care unit models designed to deliver optimal care to neonates including those born preterm with critical congenital heart disease is unknown. The objective of this study was to evaluate in-hospital outcomes after cardiac surgery across gestational ages in an institution with a dedicated neonatal cardiac program.

METHODS

This study is a single-center, retrospective review of infants who underwent cardiac surgical interventions from our dedicated neonatal cardiac intensive care program between 2006 and 2017. We evaluated in-hospital mortality and morbidity rates across all gestational ages.

RESULTS

A total of 1238 subjects met inclusion criteria over a 11-year period. Overall in-hospital mortality after cardiac surgery was 6.1%. The mortality rate in very preterm infants (n = 68; <34 weeks' gestation at birth) was 17.6% (odds ratio, 3.52 [1.4-8.53]), versus 4.3% in full-term (n = 563; 39-40 weeks) referent/control infants. Very preterm infants with isolated congenital heart disease (without evidence of other affected organ systems) experienced a mortality rate of 10.5% after cardiac surgery. Neither the late preterm (34-36 ^6/7 weeks) nor the early term (37-38 ^6/7) groups had significantly increased odds of mortality compared with full-term infants. Seventy-eight percent of very preterm infants incurred a preoperative or postoperative complication (odds ratio, 4.78 [2.61-8.97]) compared with 35% of full-term infants.

CONCLUSIONS

In this study of a single center with a dedicated neonatal cardiac program, we report some of the lowest mortality and morbidity rates after cardiac surgery in preterm infants in the recent era. The potential survival advantage of this model is most striking for very preterm infants born with isolated congenital heart disease.

Preload Dependence Fails to Predict Hemodynamic Instability During a Fluid Removal Challenge in Children

OBJECTIVES

Fluid overload increases morbidity and mortality in PICU patients. Active fluid removal improves the prognosis but may worsen organ dysfunction. Preload dependence in adults does predict hemodynamic instability induced by a fluid removal challenge (FRC). We sought to investigate the diagnostic accuracy of dynamic and static markers of preload in predicting hemodynamic instability and reduction of stroke volume during an FRC in children. We followed the Standards for Reporting of Diagnostic Accuracy statement to design conduct and report this study.

DESIGN

Prospective noninterventional cohort study.

SETTINGS

From June 2017 to April 2019 in a pediatric cardiac ICU in a tertiary hospital.

PATIENTS

Patients 8 years old or younger, with symptoms of fluid overload after cardiac surgery, were studied.

INTERVENTIONS

We confirmed preload dependence by echocardiography before and during a calibrated abdominal compression test. We then performed a challenge to remove 10-mL/kg fluid in less than 120 minutes with an infusion of diuretics. Hemodynamic instability was defined as a decrease of 10% of mean arterial pressure.

MEASUREMENT AND MAIN RESULTS

We compared patients showing hemodynamic instability with patients remaining stable, and we built receiver operative characteristic (ROC) curves. Among 58 patients studied, 10 showed hemodynamic instability. The area under the ROC curve was 0.55 for the preload dependence test (95% CI, 0.34-0.75). Using a threshold of 10% increase in stroke volume index (SVi) during calibrated abdominal compression, the specificity was 0.30 (95% CI, 0.00-0.60) and the sensitivity was 0.77 (95% CI, 0.65-0.88). Mean arterial pressure variation and SVi variation were not correlated during fluid removal; r = 0.19; 95% CI -0.07 to 0.43; p = 0.139.

CONCLUSIONS

Preload dependence is not accurate to predict hemodynamic instability during an FRC. Our data do not support a reduction in intravascular volume being mainly responsible for the reduction in arterial pressure during an FRC in children.

Mid-regional pro-adrenomedullin for diagnosing evolution after cardiac surgery in newborns: the PRONEW study

Newborns are the most vulnerable patients after cardiac surgery. Although mortality risk scores before surgery may help predict the risk of poor outcome, new tools are required, and biomarkers could add objective data to these tools. The aim of this study was to assess the ability of mid-regional pro-adrenomedullin (pro-ADM) and pro-atrial natriuretic peptide (pro-ANP) to predict poor outcome after cardiac surgery. This is a pilot diagnostic accuracy study that includes newborns and infants under 2 months admitted to an intensive care unit after cardiac surgery. Pro-ADM and pro-ANP were determined immediately upon admission. Poor outcome was defined as mortality, cardiac arrest, requiring extracorporeal support, requiring renal replacement therapy, or neurological injury. Forty-four patients were included. Twenty-six (59%) had a STAT category of ≥ 4. Ten patients (22.7%) presented a poor outcome, four of whom (9.1%) died. Pro-ADM was higher in patients with poor outcome (p = 0.024) and death (p = 0.012). Pro-ADM showed the best area under curve (AUC) for predicting poor outcome (0.735) and mortality alone (0.869). A pro-ADM of 2 nmol/L had a Sn of 75% and a Sp of 85% for predicting mortality. Pro-ADM > 2 nmol/L was independently associated with poor outcome (OR 5.8) and mortality (OR 14.1). Although higher pro-ANP values were associated with poor outcomes, no cut-off point were found. The combination of STAT ≥ 4 and the biomarkers did not enhance predictive power for poor outcome or mortality.Conclusion: Pro-ADM and pro-ANP determined immediately after surgery could be helpful for stratifying risk of poor outcome and mortality in newborns. What is Known: • Some congenital heart diseases must be corrected/palliated during the first days of life. A useful tool to predict the risk of severe complications has not been proposed. • Most unstable newborns would have higher values of biomarkers such as pro-ADM and pro-ANP related to shock and compensatory actions. What is New: • Pro-ADM and pro-ANP seem to be good biomarkers to predict poor outcome after cardiac surgery. A pro-ADM < 2 nmol/L would imply a low likelihood of a poor outcome. • Deepening the analysis of biomarkers can help in making decisions to prevent/treat complications.

The Risks of Being Tiny: The Added Risk of Low Weight for Neonates Undergoing Congenital Heart Surgery

The aims of this study were (1) to describe the additive risk of performing cardiac surgery in neonates born ≤ 2.0 kg, after accounting for the baseline risks of low birth weight, and (2) to describe the additive risk of being born ≤ 2.0 kg in neonates undergoing cardiac surgery. We used a risk difference analysis in a retrospective cohort, 2006-2016. Neonates born ≤ 2.0 kg undergoing congenital heart surgery during initial postnatal admission were included. Data were standardized alternatingly for birth weight and cardiac surgical risk using national population data to estimate the number of deaths expected had they not required cardiac surgery or were they of normal weight. Of 105 neonates ≤ 2 kg, median birth weight was 1.6 kg (IQR 1.3-1.8 kg). Median gestational age was 33 weeks (IQR 31-35 weeks). Observed operative mortality was 14.3%; 0% for neonates ≤ 1.0 kg (CI 0-33.6%), 20.6% for neonates > 1.0-1.5 kg (CI 8.7-37.9%), and 12.9% for neonates > 1.5-2.0 kg (CI 5.7-23.9%). Among neonates ≤ 2.0 kg not undergoing cardiac surgery, expected mortality was 4.8% (CI 1.6-10.8); cardiac surgery increased the risk of mortality 9.5% (CI 1.7-17.4%). Conversely, the expected risk for normal birth weight neonates undergoing cardiac surgery was 5.7% (CI 2.1-12.0%); low birth weight increased the risk of mortality 8.6% (CI 0.5-16.6%). To continue making advancements in cardiac surgery, we must understand that the rate of mortality observed in normal weight infants is not a realistic target and that, despite advances, the risk attributable to the surgery remains higher among low birth weight patients.