Right Ventricular Strain, Brain Natriuretic Peptide, and Mortality in Congenital Diaphragmatic Hernia

Congenital Diaphragmatic Hernia Patients with Left Heart Hypoplasia and Left Ventricular Dysfunction Have Highest Odds of Mortality

OBJECTIVES

To describe the scope of left ventricular (LV) dysfunction and left heart hypoplasia (LHH) in infants with congenital diaphragmatic hernia (CDH), to determine associations with CDH severity, and to evaluate the odds of extracorporeal membrane oxygenation (ECMO) and death with categories of left heart disease.

STUDY DESIGN

Demographic and clinical variables were collected from a single-center, retrospective cohort of patients with CDH from January 2017 through May 2022. Quantitative measures of LV function and LHH were prospectively performed on initial echocardiograms. LHH was defined as ≥2 of the following: z score ≤ -2 of any left heart structure or LV end-diastolic volume <3 mL. LV dysfunction was defined as shortening fraction <28%, ejection fraction <60%, or global longitudinal strain <20%. The exposure was operationalized as a 4-group categorical variable (LV dysfunction +/-, LHH +/-). Logistic regression models evaluated associations with ECMO and death, adjusting for CDH severity.

RESULTS

One hundred eight-two patients (80.8% left CDH, 63.2% liver herniation, 23.6% ECMO, 12.1% mortality) were included. Twenty percent demonstrated normal LV function and no LHH (LV dysfunction-/LHH-), 37% normal LV function with LHH (LV dysfunction-/LHH+), 14% LV dysfunction without LHH (LV dysfunction+/LHH-), and 28% both LV dysfunction and LHH (LV dysfunction+/LHH+). There was a dose-response effect between increasing severity of left heart disease, ECMO use, and mortality. LV dysfunction+/LHH + infants had the highest odds of ECMO use and death, after adjustment for CDH severity [OR (95% CI); 1.76 (1.20, 2.62) for ECMO, 2.76 (1.63, 5.17) for death].

CONCLUSIONS

In our large single-center cohort, patients with CDH with LV dysfunction+/LHH + had the highest risk of ECMO use and death.

"Heart of the Matter": Cardiac Dysfunction in Congenital Diaphragmatic Hernia

Despite advances in caring for neonates with congenital diaphragmatic hernia (CDH), mortality and morbidity continues to be high. Additionally, the pathophysiology of cardiac dysfunction in this condition is poorly understood. Postnatal cardiac dysfunction in neonates with CDH may be multifactorial with origins in fetal life. Mechanical obstruction, competition from herniated abdominal organs into thoracic cavity combined with redirection of ductus venosus flow away from patent foramen ovale leading to smaller left-sided structures may be a contributing factor. This shunting decreases left atrial and left ventricular blood volume, which may result in altered micro- and macrovascular aberrations affecting cardiac development in the prenatal period. Direct mass effect from herniated intra-abdominal contents restricting cardiac growth and/or reduced left ventricular preload may contribute independently to left ventricular dysfunction in the absence of right ventricular dysfunction and or pulmonary hypertension. With variable clinical phenotypes of cardiac dysfunction, pulmonary hypertension, and respiratory failure in patients with CDH, there is increased need for individualized diagnosis and tailored therapy. Routine use of therapy such as inhaled nitric oxide and sildenafil that induces significant pulmonary vasodilation may be detrimental in left ventricle dysfunction, whereas in a patient with pure right ventricle dysfunction, they may be beneficial. Targeted functional echocardiography serves as a real-time tool for defining the pathophysiology and aids optimization of vasoactive therapy in affected neonates. KEY POINTS: · Cardiac dysfunction in neonates with CDH is multifactorial.. · Postnatal cardiac dysfunction in patients with CDH has its origins in fetal life.. · Right ventricular dysfunction contributes to systemic hypotension.. · Left ventricular dysfunction contributes to systemic hypotension.. · Supportive therapy should be tailored to clinical phenotype..

Diagnosis and management of congenital diaphragmatic hernia: a 2023 update from the Canadian Congenital Diaphragmatic Hernia Collaborative

OBJECTIVE

The Canadian Congenital Diaphragmatic Hernia (CDH) Collaborative sought to make its existing clinical practice guideline, published in 2018, into a 'living document'.

DESIGN AND MAIN OUTCOME MEASURES

Critical appraisal of CDH literature adhering to Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Evidence accumulated between 1 January 2017 and 30 August 2022 was analysed to inform changes to existing or the development of new CDH care recommendations. Strength of consensus was also determined using a modified Delphi process among national experts in the field.

RESULTS

Of the 3868 articles retrieved in our search that covered the 15 areas of CDH care, 459 underwent full-text review. Ultimately, 103 articles were used to inform 20 changes to existing recommendations, which included aspects related to prenatal diagnosis, echocardiographic evaluation, pulmonary hypertension management, surgical readiness criteria, the type of surgical repair and long-term health surveillance. Fifteen new CDH care recommendations were also created using this evidence, with most related to the management of pain and the provision of analgesia and neuromuscular blockade for patients with CDH.

CONCLUSIONS

The 2023 Canadian CDH Collaborative's clinical practice guideline update provides a management framework for infants and children with CDH based on the best available evidence and expert consensus.

Optimal Global Longitudinal Strain Thresholds for Pediatric Heart Surgery: Insights from a University Hospital

Congenital heart diseases impact millions annually, with pediatric care lacking suitable risk assessment tools. This research seeks to illuminate the association between the global longitudinal strain (GLS) and the subsequent impact on postoperative outcomes, contributing to a deeper understanding of its predictive value in the pediatric population affected by congenital heart diseases. An observational, analytic, longitudinal, and prospective study was conducted from May 2022 to May 2023, including all patients under 18 undergoing heart surgery with cardiopulmonary bypass (CBP). Patients not classifiable within the Risk Adjustment for Congenital Heart Surgery were excluded. Using transesophageal echocardiography, GLS was measured pre- and post-CPB. Receiver operating characteristic curve analysis determined GLS cut-off points for 30-day mortality risk, using Youden's method for optimal sensitivity and specificity. Bivariate and multivariate analysis identified the relationships between clinical variables. Eighty-nine patients undergoing congenital heart surgery were included. Fifteen deaths occurred. The area under the curve (AUC) for each GLS classification (pre, post, index) demonstrated effective discriminatory capacity (> 0.70) in predicting 30-day mortality. Pre-CBP GLS showed the strongest predictive power (AUC 0.833, IQR: 0.731 - 0.936) with a cut-off point of 12. Values lower than the cut-off point of pre-CPB GLS correlated with increased vasoactive-inotropic Scores and longer mechanical ventilation. GLS measurement is a reproducible method for assessing ventricular function in pediatric heart surgery, showing potential as a prognostic tool. This study marks the initial effort to establish cut-off points for preoperative GLS, postoperative GLS, and the strain index.

Update on Management and Outcomes of Congenital Diaphragmatic Hernia

Infants with congenital diaphragmatic hernia (CDH) benefit from comprehensive multidisciplinary teams that have experience in caring for the unique and complex issues associated with CDH. Despite prenatal referral to specialized high-volume centers, advanced ventilation strategies and pulmonary hypertension management, and extracorporeal membrane oxygenation, mortality and morbidity remain high. These infants have unique and complex issues that begin in fetal and infant life, but persist through adulthood. Here we will review the literature and share our clinical care pathway for neonatal care and follow up. While many advances have occurred in the past few decades, our work is just beginning to continue to improve the mortality, but also importantly the morbidity of CDH.

Treprostinil in Neonates with Congenital Diaphragmatic Hernia-Related Pulmonary Hypertension

OBJECTIVE

To describe our experience with treprostinil, evaluate correlations with cardiac function, and assess for adverse effects in neonates with congenital diaphragmatic hernia-related pulmonary hypertension (CDH-PH).

STUDY DESIGN

A retrospective review of a single-center prospective registry at a quaternary care children's hospital. Patients included in the study had CDH-PH treated with treprostinil between April 2013 and September 2021. Assessed outcomes were brain-type natriuretic peptide levels and quantitative echocardiographic parameters collected at baseline, 1 week, 2 weeks, and 1 month after treprostinil initiation. Right ventricular (RV) function was assessed by tricuspid annular plane systolic excursion Z-score and speckle tracking echocardiography (global longitudinal and free wall strain). Septal position and left ventricular (LV) compression were assessed by eccentricity index and M-mode Z-scores.

RESULTS

Fifty-one patients were included, with an average expected/observed lung-to-head ratio of 28.4 ± 9.0%. Most patients required extra-corporeal membrane oxygenation (n = 45, 88%). Survival to hospital discharge was 31/49 (63%). Treprostinil was initiated at a median age of 19 days with a median effective dose of 34 ng/kg/minute. Median baseline brain-type natriuretic peptide level decreased from 416.9 pg/mL to 120.5 pg/mL after 1 month. Treprostinil was associated with improved tricuspid annular plane systolic excursion Z-score, RV global longitudinal strain, RV free wall strain, LV eccentricity index, and LV diastolic and systolic dimensions, reflecting less compression by the RV, regardless of ultimate patient survival. No serious adverse effects were recorded.

CONCLUSIONS

In neonates with CDH-PH, treprostinil administration is well tolerated and is associated with improved RV size and function.

Inotropic score and vasoactive inotropic score as predictors of outcomes in congenital diaphragmatic hernia: A single center retrospective study

BACKGROUND

Neonates with congenital diaphragmatic hernia (CDH) have varying degrees of pulmonary hypoplasia, pulmonary hypertension (PH) and cardiac dysfunction. These neonates frequently require vasoactive support and are at high risk for mortality and morbidity, including prolonged ventilator support, need for extracorporeal membrane oxygenation (ECMO), prolonged length of stay, and need for tracheostomy. However, identifying which infants are at increased risk can be challenging. In this study, we sought to investigate the utility of the inotropic score (IS) and vasoactive inotropic score (VIS) as tools to predict significant clinical outcomes and overall survival in patients with CDH. Additionally, we evaluated the correlation between IS/VIS and postnatal echocardiographic variables.

METHODS

This was a retrospective chart review of 57 patients with CDH whose postnatal care was based on a standardized institutional protocol. We calculated the IS/VIS at 6-, 12-, 24-, 48 hours of life (HOL), on the day of CDH repair and 24- and 48 hours after surgical repair. The association of these scores with postnatal echocardiographic markers was analyzed using Pearson's correlation and linear regression, while logistic regression was used for binary outcomes, and Cox proportional hazards regression was used to assess associations with survival.

RESULTS

We found that every one-unit increase in IS/VIS at 6 HOL was associated with 13% increase in the odds of ECMO (p = 0.034) and 10.1% increase in risk of death (p = 0.021). An increase in IS/VIS at 12-, 24- and 48-HOL was associated with posterior septal bowing in the first postnatal echocardiogram (p < 0.05 for all). Additionally, we noted an inverse relationship between IS (r = -0.281, p = 0.036) and VIS (r = -0.288, p = 0.031) on the day of repair and left ventricle (LV) systolic function in first postnatal echocardiogram. Increase in IS (r = -0.307, p = 0.024) and VIS (r = -0.285, p = 0.037) on the day of repair was associated with decreased LV function on the post-repair echocardiogram.

CONCLUSION

This retrospective study showed a significant association between IS/VIS obtained at various time points with clinical outcomes and echocardiographic findings in CDH, which could be used to guide prognosis and management in this patient population.

Imaging in neonatal respiratory disease

The purpose of this review is to describe the current state of the art in clinical imaging for NICU patients, divided into major areas that correspond to likely phenotypes of neonatal respiratory disease: airway abnormalities, parenchymal disease, and pulmonary vascular disease. All common imaging modalities (ultrasound, X-ray, CT, and MRI) are discussed, with an emphasis on modalities that are most relevant to the individual underlying aspects of disease. Some promising aspects of dynamic and functional imaging are included, where there may be future clinical applicability.

Diagnosis & management of pulmonary hypertension in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) contributes to neonatal morbidity and mortality worldwide. Pulmonary hypertension (PH) is a key component of CDH pathophysiology and critical consideration for management and therapeutic options. PH associated with CDH has traditionally been attributed to pulmonary vascular maldevelopment and associated lung parenchymal hypoplasia, leading to pre-capillary increase in pulmonary vascular resistance (PVR). However, there is increasing recognition that left ventricular hypoplasia, dysfunction and elevated end diastolic pressure may contribute to post-capillary pulmonary hypertension in CDH patients. The interplay of these mechanisms and associated dysfunction in the right and left ventricles results in variable hemodynamic phenotypes in CDH. Clinical assessment of individual phenotype may help guide personalized management strategies, including effective use of pulmonary vasodilators and extra-corporeal membrane oxygenation. Ongoing investigation of the underlying mechanisms of PH in CDH, and efficacy of physiology-based treatment approaches may support improvement in outcomes in this challenging condition.

Increased N-terminal Pro-B-Type Natriuretic Peptide during Extracorporeal Life Support Is Associated with Poor Outcome in Neonates with Congenital Diaphragmatic Hernia

OBJECTIVES

To evaluate the prognostic information derived from the daily measurements of N-terminal pro-B-type natriuretic peptide (proBNP) in neonates with congenital diaphragmatic hernia undergoing extracorporeal life support (ECLS).

STUDY DESIGN

Plasma proBNP was prospectively measured daily during the first week of ECLS using an electrochemiluminescence immunoassay. Patients (n = 63) were allocated according to outcome: survivors (group 1, n = 35); nonsurvivors with successful weaning (defined as survival for >12 hours after ECLS discontinuation) (group 2, n = 16); nonsurvivors with unsuccessful weaning (group 3, n = 12). ProBNP kinetics were compared using Kruskal-Wallis testing and correlated with pulmonary hypertension and cardiac dysfunction on echocardiography using the Spearman correlation coefficient.

RESULTS

Infants in group 3 presented significantly higher proBNP values from day 3 to day 6 compared with group 1 and 2. Overall mortality among patients with the highest proBNP values on day 1 was 30.6% compared with 63% in those patients with at least 1 higher value on day 2 to day 7. In patients with a late increase (day 4 to day 7) in proBNP the mortality was 70%, compared with 32.6% in those with proBNP below the value on day 1. Weaning failure was 35% in patients with a late increase and 11.6% in those without a late increase. ProBNP correlated significantly with pulmonary hypertension and cardiac dysfunction before and during ECLS.

CONCLUSIONS

Absolute proBNP values are associated with weaning failure but not overall mortality in neonates with congenital diaphragmatic hernia undergoing ECLS. Echocardiographic findings correlate well with proBNP values.

Use of Prostaglandin E1 in the Management of Congenital Diaphragmatic Hernia-A Review

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly, whose presentation is complicated by pulmonary hypertension (PH), pulmonary hypoplasia, and myocardial dysfunction, each of which have significant impact on short-term clinical management and long-term outcomes. Despite many advances in therapy and surgical technique, optimal CDH management remains a topic of debate, due to the variable presentation, complex pathophysiology, and continued impact on morbidity and mortality. One of the more recent management strategies is the use of prostaglandin E1 (PGE1) infusion in the management of PH associated with CDH. PGE1 is widely used in the NICU in critical congenital cardiac disease to maintain ductal patency and facilitate pulmonary and systemic blood flow. In a related paradigm, PGE1 infusion has been used in situations of supra-systemic right ventricular pressures, including CDH, with the therapeutic intent to maintain ductal patency as a "pressure relief valve" to reduce the effective afterload on the right ventricle (RV), optimize cardiac function and support pulmonary and systemic blood flow. This paper reviews the current evidence for use of PGE1 in the CDH population and the opportunities for future investigations.

The heart in congenital diaphragmatic hernia: Knowns, unknowns, and future priorities

There is growing recognition that the heart is a key contributor to the pathophysiology of congenital diaphragmatic hernia (CDH), in conjunction with developmental abnormalities of the lung and pulmonary vasculature. Investigations to date have demonstrated altered fetal cardiac morphology, notably relative hypoplasia of the fetal left heart, as well as early postnatal right and left ventricular dysfunction which appears to be independently associated with adverse outcomes. However, many more unknowns remain, not least an understanding of the genetic and cellular basis for cardiac dysplasia and dysfunction in CDH, the relationship between fetal, postnatal and long-term cardiac function, and the impact on other parts of the body especially the developing brain. Consensus on how to measure and classify cardiac function and pulmonary hypertension in CDH is also required, potentially using both non-invasive imaging and biomarkers. This may allow routine assessment of the relative contribution of cardiac dysfunction to individual patient pathophysiological phenotype and enable better, individualized therapeutic strategies incorporating targeted use of fetal therapies, cardiac pharmacotherapies, and extra-corporeal membrane oxygenation (ECMO). Collaborative, multi-model approaches are now required to explore these unknowns and fully appreciate the role of the heart in CDH.

Unsolved problems in CDH follow-up

In patients affected by CDH, survival beyond the neonatal period continues to increase thanks to technological and pharmacological improvements. Conversely, patients, families and caregivers are more and more frequently facing "new" complex late comorbidities, including chronic pulmonary and cardiac dysfunctions, neurodevelopmental challenges, and specific nutritional requirements, that often require ongoing long-term medical or surgical care. Therefore, late morbidity is now a key focus in clinical care of CDH. The aims of this paper are to stress some of the most important "unsolved problems" for CDH patients at long-term follow-up.