Enhanced characterization of ventricular performance after coarctation repair in neonates and young children. Ann Thorac Surg. 2013;96:629-636. [PMID: 23806230 DOI: 10.1016/j.athoracsur.2013.04.058]

The mechanics of congenital heart disease: from a morphological trait to the functional echocardiographic evaluation

Advances in pediatric cardiac surgery have resulted in a recent growing epidemic of children and young adults with congenital heart diseases (CHDs). In these patients, congenital defects themselves, surgical operations and remaining lesions may alter cardiac anatomy and impact the mechanical performance of both ventricles. Cardiac function significantly influences outcomes in CHDs, necessitating regular patient follow-up to detect clinical changes and relevant risk factors. Echocardiography remains the primary imaging method for CHDs, but clinicians must understand patients' unique anatomies as different CHDs exhibit distinct anatomical characteristics affecting cardiac mechanics. Additionally, the use of myocardial deformation imaging and 3D echocardiography has gained popularity for enhanced assessment of cardiac function and anatomy. This paper discusses the role of echocardiography in evaluating cardiac mechanics in most significant CHDs, particularly its ability to accommodate and interpret the inherent anatomical substrate in these conditions.

Diagnosis and surgical outcomes of coarctation of the aorta in pediatric patients: a retrospective study

BACKGROUND

Coarctation of the aorta (CoA) is a common congenital cardiovascular malformation, and improvements in the diagnostic process for surgical decision-making are important. We sought to compare the diagnostic accuracy of transthoracic echocardiography (TTE) with computed tomographic angiography (CTA) to diagnose CoA.

METHODS

We retrospectively reviewed 197 cases of CoA diagnosed by TTE and CTA and confirmed at surgery from July 2009 to August 2019.

RESULTS

The surgical findings confirmed that 19 patients (9.6%) had isolated CoA and 178 (90.4%) had CoA combined with other congenital cardiovascular malformations. The diagnostic accuracy of CoA by CTA was significantly higher than that of TTE (χ2 = 6.52, p = 0.01). In contrast, the diagnostic accuracy of TTE for associated cardiovascular malformations of CoA was significantly higher than that of CTA (χ2 = 15.36, p < 0.0001). Infants and young children had more preductal type of CoA, and PDA was the most frequent cardiovascular lesion associated with CoA. The pressure gradient was significantly decreased after the first operation, similar at 6 months, 1 year, and 3 years follow-ups by TTE.

CONCLUSIONS

CTA is more accurate as a clinical tool for diagnosing CoA; however, TTE with color Doppler can better identify associated congenital cardiovascular malformations. Therefore, combining TTE and CTA would benefit clinical evaluation and management in patients suspected of CoA. TTE was valuable for post-operation follow-up and clinical management.

Implications of Left Ventricular Dysfunction at Presentation for Infants with Coarctation of the Aorta

Infants with aortic coarctation may present with left ventricular (LV) dysfunction which may complicate the postoperative course and lead to increased healthcare costs. We aimed to define the prevalence of moderate to severe left ventricular (LV) systolic dysfunction, evaluate time to recovery, and compare health care costs. Single-center retrospective cohort study at a tertiary care hospital was conducted. Infants < 6 months old at diagnosis with aortic coarctation were identified using surgical codes for coarctation repair between January 2010 and May 2018. Moderate to severe dysfunction was defined as ejection fraction (EF) < 40%. Of 160 infants studied, 18 (11%) had moderate to severe LV dysfunction at presentation. Compared to those with better LV function, infants with moderate to severe LV dysfunction were older at presentation (12 vs. 6 days, p = 0.004), had more postoperative cardiac intensive care unit (ICU) days (5 vs. 3, p < 0.001), and more ventilator days (3.5 vs. 1, p < 0.001). The median time to normal LV EF (≥ 55%) was 6 days postoperatively (range 1-230 days). Infants presenting with moderate to severe LV dysfunction had higher index hospitalization costs ($90,560 vs. $59,968, p = 0.02), but no difference in cost of medical follow-up for the first year following discharge ($3,078 vs. $2,568, p = 0.46). In the current era, > 10% of infants with coarctation present with moderate to severe LV dysfunction that typically recovers. Those with moderate to severe dysfunction had longer duration of mechanical ventilation and postoperative cardiac ICU stays, likely driving higher costs of index hospitalization.

Early cardiac remodeling in aortic coarctation: insights from fetal and neonatal functional and structural assessment

OBJECTIVES

Coarctation of the aorta (CoA) is associated with left ventricular (LV) dysfunction in neonates and adults. Cardiac structure and function in fetal CoA and cardiac adaptation to early neonatal life have not been described. We aimed to investigate the presence of cardiovascular structural remodeling and dysfunction in fetuses with CoA and their early postnatal cardiac adaptation.

METHODS

This was a prospective observational case-control study, conducted between 2011 and 2018 in a single tertiary referral center, of fetuses with CoA and gestational age-matched normal controls. All fetuses/neonates underwent comprehensive echocardiographic evaluation in the third trimester of pregnancy and after birth. Additionally, myocardial microstructure was assessed in one fetal and one neonatal CoA-affected heart specimen, using synchrotron radiation-based X-ray phase-contrast microcomputed tomography and histology, respectively.

RESULTS

We included 30 fetuses with CoA and 60 gestational age-matched controls. Of these, 20 CoA neonates and 44 controls were also evaluated postnatally. Fetuses with CoA showed significant left-to-right volume redistribution, with right ventricular (RV) size and output dominance and significant geometry alterations with an abnormally elongated LV, compared with controls (LV midventricular sphericity index (median (interquartile range; IQR), 2.4 (2.0-2.7) vs 1.8 (1.7-2.0); P < 0.001). Biventricular function was preserved and no ventricular hypertrophy was observed. Synchrotron tomography and histological assessment revealed normal myocyte organization in the fetal and neonatal specimens, respectively. Postnatally, the LV in CoA cases showed prompt remodeling, becoming more globular (LV midventricular sphericity index (mean ± SD), 1.5 ± 0.3 in CoA vs 1.8 ± 0.2 in controls; P < 0.001) with preserved systolic and normalized output, but altered diastolic, parameters compared with controls (LV inflow peak velocity in early diastole (mean ± SD), 97.8 ± 14.5 vs 56.5 ± 12.9 cm/s; LV inflow peak velocity in atrial contraction (median (IQR), 70.5 (60.1-84.9) vs 47.0 (43.0-55.0) cm/s; LV peak myocardial velocity in atrial contraction (mean ± SD), 5.1 ± 2.6 vs 6.3 ± 2.2 cm/s; P < 0.05). The neonatal RV showed increased longitudinal function in the presence of a patent arterial duct.

CONCLUSIONS

Our results suggest unique fetal cardiac remodeling in CoA, in which the LV stays smaller from the decreased growth stimulus of reduced volume load. Postnatally, the LV is acutely volume-loaded, resulting in an overall geometry change with higher filling velocities and preserved systolic function. These findings improve our understanding of the evolution of CoA from fetal to neonatal life. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Circulating biomarkers of left ventricular hypertrophy in pediatric coarctation of the aorta

OBJECTIVE

Patients undergoing surgical repair of aortic coarctation have a 50% risk of pathologic left ventricular remodeling (increased left ventricular mass or relative wall thickness). Endothelin 1, ST2, galectin 3, norepinephrine and B-natriuretic peptide are biomarkers that have been associated with pathologic LV change in adult populations but their predictive value following pediatric coarctation repair are not known.

HYPOTHESIS

Biomarker levels at coarctation repair will predict persistent left ventricular remodeling at 1-year follow up.

DESIGN

Prospective, cohort study of 27 patients' age 2 days-12 years with coarctation of the aorta undergoing surgical repair. Echocardiograms were performed preoperation, postoperation, and at 1-year follow-up. Plasma biomarker levels were measured at the peri-operative time points. Association between biomarker concentrations and echocardiographic parameters was assessed.

RESULTS

Neither left ventricular mass index nor relative wall thickness varied from pre-op to post-op. At pre-op, relative wall thickness was elevated in 52% and left ventricular mass index was elevated in 22%; at follow-up, relative wall thickness was elevated in 13% and left ventricular mass index was elevated in 8%. Presence of residual coarctation did not predict left ventricular remodeling (AUC 0.59; P > .05). Multivariable receiver operating characteristic curve combining pre-op ST2 and endothelin 1 demonstrated significant predictive ability for late pathologic left ventricular remodeling (AUC 0.85; P = .02).

CONCLUSIONS

Persistent left ventricular hypertrophy and abnormal relative wall thickness at intermediate-term follow-up was rare compared to previous studies. A model combining pre-op endothelin 1 and ST2 level demonstrated reasonable accuracy at predicting persistent abnormalities in this cohort. Larger studies will be needed to validate this finding and further explore the mechanism of persistent left ventricular remodeling in this population.

Endothelin-1 activation in pediatric patients undergoing surgical coarctation of the aorta repair

AIM

To determine endothelin-1 (ET-1) concentration before and after surgical coarctectomy and evaluate its association with left ventricular geometric change.

METHODS

A prospective, cohort study of 24 patients aged 2 d to 10 years with coarctation of the aorta undergoing surgical repair. A sub-cohort of patients with age < 1 mo was classified as “neonates”. Echocardiograms were performed just prior to surgery and in the immediate post-op period to assess left ventricle mass index and relative wall thickness (RWT). Plasma ET-1 levels were assessed at both time points. Association between ET-1 levels and ventricular remodeling was assessed.

RESULTS

Patients < 1 year demonstrated higher pre-op ET-1 than post-op (2.8 pg/mL vs 1.9 pg/mL, P = 0.02). Conversely, patients > 1 year had no change in ET-1 concentration before and after surgery (1.1 vs 1.4, NS). Pre-op, patients < 1 year demonstrated significantly higher ET-1 than older children (2.8 vs 1.1, P = 0.001). Post-op there was no difference between the age groups (1.9 vs 1.4, NS). Neither RWT nor left ventricle mass index (LVMI) varied from pre-op to post-op. The subset of neonates showed a strong positive correlation between pre-op ET-1 and RWT (r = 0.92, P = 0.001). Patients with ET-1 > 2 pg/mL pre-op demonstrated higher LVMI (65.7 g/m^2.7vs 38.5 g/m^2.7, P = 0.004) and a trend towards higher RWT (45% vs 39%, P = 0.07) prior to repair than those with lower ET-1 concentration.

CONCLUSION

ET-1 concentration is significantly variable in the peri-operative period surrounding coarctectomy. Older children and infants have different responses to surgical repair suggesting different mechanisms of activation.

Reference Ranges of Left Ventricular Strain Measures by Two-Dimensional Speckle-Tracking Echocardiography in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Establishment of the range of reference values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE)-derived left ventricular (LV) strain is a prerequisite for its routine clinical adoption in pediatrics. The aims of this study were to perform a meta-analysis of normal ranges of LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) measurements derived by 2DSTE in children and to identify confounding factors that may contribute to variance in reported measures.

METHODS

A systematic review was launched in MEDLINE, Embase, Scopus, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library. Search hedges were created to cover the concepts of pediatrics, STE, and left-heart ventricle. Two investigators independently identified and included studies if they reported 2DSTE-derived LV GLS, GCS, or GRS. The weighted mean was estimated by using random effects models with 95% CIs, heterogeneity was assessed using the Cochran Q statistic and the inconsistency index (I(2)), and publication bias was evaluated using the Egger test. Effects of demographic (age), clinical, and vendor variables were assessed in a metaregression.

RESULTS

The search identified 2,325 children from 43 data sets. The reported normal mean values of GLS among the studies varied from -16.7% to -23.6% (mean, -20.2%; 95% CI, -19.5% to -20.8%), GCS varied from -12.9% to -31.4% (mean, -22.3%; 95% CI, -19.9% to -24.6%), and GRS varied from 33.9% to 54.5% (mean, 45.2%; 95% CI, 38.3% to 51.7%). Twenty-six studies reported longitudinal strain only from the apical four-chamber view, with a mean of -20.4% (95% CI, -19.8% to -21.7%). Twenty-three studies reported circumferential strain (mean, -20.3%; 95% CI, -19.4% to -21.2%) and radial strain (mean, 46.7%; 95% CI, 42.3% to 51.1%) from the short-axis view at the midventricular level. A significant apex-to-base segmental longitudinal strain gradient (P < .01) was observed in the LV free wall. There was significant between-study heterogeneity and inconsistency (I(2) > 94% and P < .001 for each strain measure), which was not explained by age, gender, body surface area, blood pressure, heart rate, frame rate, frame rate/heart rate ratio, tissue-tracking methodology, location of reported strain value along the strain curve, ultrasound equipment, or software. The metaregression showed that these effects were not significant determinants of variations among normal ranges of strain values. There was no evidence of publication bias (P = .40).

CONCLUSIONS

This study defines reference values of 2DSTE-derived LV strain in children on the basis of a meta-analysis. In healthy children, mean LV GLS was -20.2% (95% CI, -19.5% to -20.8%), mean GCS was -22.3% (95% CI, -19.9% to -24.6%), and mean GRS was 45.2% (95% CI, 38.3% to 51.7%). LV segmental longitudinal strain has a stable apex-to-base gradient that is preserved throughout maturation. Although variations among different reference ranges in this meta-analysis were not dependent on differences in demographic, clinical, or vendor parameters, age- and vendor-specific referenced ranges were established as well.

Insights from Cardiac Mechanics after Three Decades from Successfully Repaired Aortic Coarctation

BACKGROUND AND AIMS

Patients who underwent a successful repair of the aortic coarctation show chronic hyperdynamic state and normal left ventricular (LV) geometry; however, there are few data regarding the LV systolic function in the long term. Accordingly, we assessed LV systolic mechanics and factors associated with LV systolic dysfunction (LVSD) in patients with repaired CoA.

METHODS

Clinical and echocardiographic data from 19 repaired CoA were analyzed 28 ± 13 years after surgery. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were analyzed as indexes of LV circumferential and longitudinal systolic function, respectively. Echocardiographic data of CoA patients were compared with 19 patients matched for age and hypertension and 38 healthy controls. Sc-MS was considered impaired if <89%, S' if <8.5 cm/s (10th percentiles of healthy controls, respectively).

RESULTS

There were no statistical differences between study groups in LV volumes, mass and geometry. LV ejection fraction and Sc-MS were similar in all groups, however, CoA group had a significantly lower peak S' in comparison with matched and healthy controls (7.1 ± 1.3, 10.3 ± 1.9, and 11.1 ± 1.5, respectively; all P < 0.001). Prevalence of longitudinal LVSD defined as low S' was 84% in CoA, 13% in matched, and 5% in healthy control group (all P<0.05). Multivariate logistic regression analysis revealed that low peak S' was independently related to higher E/E' ratio and the presence of CoA.

CONCLUSIONS

Patients who underwent a successful repair of CoA commonly show asymptomatic longitudinal LVSD associated with worse LV diastolic function in the long-term follow-up.

Left ventricular response to pressure afterload in children: aortic stenosis and coarctation: a systematic review of the current evidence

Congenital aortic stenosis (CAS) and Coarctation of Aorta (CoA) represent two forms of pressure afterload that affect the left ventricle (LV), hence require regular echocardiographic monitoring. Subclinical dysfunction of the LV exists even in asymptomatic patients with preserved left ventricular ejection fraction (EF), implying low sensitivity of EF in predicting optimum time for intervention. In this article we review patterns of LV myocardial deformation before and after correction of CAS and CoA in infants, children and adolescents, showing their important role in monitoring the course of LV dysfunction. A systematic search using PubMed was performed and suitable studies are presented on a narrative form. Normal EF and/or fractional shortening (FS), with subclinical myocardial dysfunction are reported in all studies before intervention. The short-term results, after intervention, were related to the type of procedure, with no improvement or further deterioration related to surgery but immediate improvement after balloon intervention. Long term follow-up showed further improvement but still subnormal function. Thus correction of CAS and CoA before irreversible LV dysfunction is vital, and requires longitudinal studies in order to identify the most accurate parameter for function prognostication. Until then, conventional echocardiographic parameters together with myocardial velocities and deformation parameters should continue to provide follow-up reproducible measures of ventricular function.