Electrocardiographic Characteristics in 438 Neonates with Atrial Septal Defects

Arrhythmias and electrocardiographic (ECG) abnormalities are common among patients with atrial septal defects (ASDs). We studied a large cohort of neonates with ASDs to investigate whether ECG abnormalities are present at this early stage or develop later, secondary to hemodynamic changes. We analyzed the echocardiograms and ECGs from the Copenhagen Baby Heart Study, a population-based cohort study. We compared ECG characteristics of 438 neonates with secundum ASDs to 1314 matched controls. In subgroup analyses, we investigated whether electrocardiographic characteristics were associated with age at examination. Neonates with ASDs (median age, 11 days; males, 51%) had longer P-wave durations (58 vs. 56 ms, p < 0.001), PR intervals (100 vs. 96 ms, p < 0.001), and a more rightward-shifted QRS axis (116 vs. 114 degrees, p = 0.032) compared to controls (median age, 10 days; males, 51%). There were no differences between cases and controls in the P-wave area, amplitude, or axis. Subgroup analyses showed that the differences in P-wave duration and PR interval were present in neonates examined in the first week after birth. The difference in the QRS axis was not found in neonates examined this early but was found in neonates examined at age two to four weeks. In conclusion, ASDs are associated with ECG changes from the neonatal phase. The P-wave duration and PR interval are longer in neonates with ASDs when compared to controls as early as the first week after birth, indicating that these changes are not purely secondary, but that neonates with an ASD have altered cardiac electrical activity.ClinicalTrials.gov Identifier NCT02753348 (April 27, 2016).

The Neonatal QRS Complex and Its Association with Left Ventricular Mass

To evaluate QRS complex features during the first month of life and the association with echocardiographic measurements of left ventricular mass in neonates. Prospective cohort study of neonates with electrocardiography (ECG) and echocardiography performed during the first month of life. Left ventricular mass index (LVMI) was determined by echocardiography and the correlation with electrocardiographic markers of LVMI outliers (≥ 98th percentile) were analyzed. We included 17,450 neonates (52% boys; median age at examination 11 days) and found an increase in median QRS duration and LVMI during the first month of life (54 vs. 56 ms and 24.7 vs. 28.6 g/m2 at days 0-4 and 25-30, respectively; both p < 0.001). All investigated ECG features (QRS duration, QRS area in V1/V6, maximum amplitudes of S-V1/R-V6, and the Sokolow-Lyon voltage product) showed no to low correlation with LVMI, resulting in low sensitivities (0-9.0%), but high specificities (97.2-98.1%), and area under the curve values close to the identity line (0.49-0.61) for identifying LVMI outliers. Adjustment of outlier definition for LVMI and threshold for QRS features had no significant effect on sensitivity. We present reference values for QRS complex features and their association with LVMI in neonates from a large, unselected, population-based cohort. The QRS complex gradually evolved during the first month of life but had a low correlation with LVMI. Our results indicate a poor diagnostic value of using ECG features to identify LVMI outliers in neonates.Trial Registry Copenhagen Baby Heart, NCT02753348, https://clinicaltri-als.gov/ct2/show/NCT02753348?cond=Copenhagen+Baby+Heart&draw=2&rank=1 , deidentified individual participant data will not be made available.

Impact of maternal age and body mass index on the structure and function of the heart in newborns: a Copenhagen Baby Heart Study

BACKGROUND

Maternal obesity and advanced age have been associated with an increased risk of structural congenital heart defects in the offspring. Whether these factors may also cause abnormalities in infant cardiac dimension and function is unknown. This study investigates whether maternal body mass index (BMI) and maternal age are associated with changes in left ventricular (LV) dimensions and function in the newborn.

METHODS

Infants enrolled in the Copenhagen Baby Heart Study (CBHS), who were born at term, and contributed with a transthoracic echocardiography (TTE) within 60 days of birth were included. The exposure variables were prepregnancy maternal BMI (kg/m2) < 18.5; 18.5-24.9 (reference); 25-29.9; 30-34.9 and ≥ 35 and maternal age (years) < 25; 25-29; 30-34 (reference); 35-39 and ≥ 40. Outcomes were LV parameters ascertained by 2D-echocardiography. Associations between each maternal factor and infant LV parameters were analysed with either a linear model adjusted for the child's weight and length at birth, gestational age, sex, age at TTE, and maternal smoking, or a linear mixed model, further adjusted for random effects of analyst and month of analysis. Analyses investigating impact of maternal BMI were adjusted for maternal age, and vice versa.

RESULTS

The study cohort included 24,294 infants. Compared with infants in the BMI reference group, infants born to women with a BMI ≥ 25 kg/m2 generally had smaller measures of LV internal diameters in end-diastole, reaching statistical significance for BMI 30-34.9 kg/m2 [-0.11 ± 0.04 mm, p = 0.01]. All groups of infants born to women with a BMI ≥ 25 kg/m2 had significantly smaller LV internal diameters in end-systole: BMI 25-29.9 kg/m2 [-0.04 ± 0.02 mm, p = 0.04], BMI 30-34.9 kg/m2 [-0.12 ± 0.03 mm, p = 0.001] and BMI ≥ 35 kg/m2 [-0.11 ± 0.05 mm, p = 0.03]. Compared with infants in the age reference group, infants born to women ≥ 40 years had significantly smaller LV internal diameters in end-diastole [-0.15 ± 0.04 mm, p = 0.001] and end-systole [-0.09 ± 0.04 mm, p = 0.009].

CONCLUSIONS

Systematic population-based echocardiography of infants showed that a maternal prepregnancy BMI ≥ 25 kg/m2 and maternal age ≥ 40 years were associated with smaller systolic and diastolic LV diameters. The long-term effects are unknown.

CLINICAL TRIAL REGISTRATION

April 2016, Copenhagen Baby Heart, NCT02753348 .

The Impact of Maternal and Perinatal Factors on the Neonatal Electrocardiogram

INTRODUCTION

Myocardial development is still transitioning by the time of birth making the cardiomyocyte vulnerable to maternal and perinatal factors. We aimed at investigating the impact of maternal and perinatal factors on the neonatal electrocardiogram.

METHODS

In a prospective cohort study, neonates underwent cardiac evaluation with electrocardiograms and echocardiograms (age 0-30 days). Associations between medical and demographic data, pregnancy, and birth-related factors, and electrocardiographic parameters were assessed.

RESULTS

A total of 15,928 singletons with normal echocardiograms were included (52% boys). Neonates were divided into groups by accumulated number of maternal/perinatal factors: 0, 1, 2, 3, 4, and ≥5, and between-group differences in electrocardiographic parameters were analysed. We observed an additive effect with a leftward shift of the QRS axis and QT prolongation (all p < 0.01). Comparing extreme groups (0 vs. ≥5 maternal/perinatal factors), we found a 4.3% more left-shifted QRS axis (117 vs. 112°, p < 0.001) and a 0.8% prolonged QTcFridericia (QTcF; 363 vs. 366 ms, p < 0.001); the effect on QTcF was most pronounced in neonates examined in the first week of life (360 vs. 368 ms, p < 0.0001).

CONCLUSION

We observed a cumulative effect of maternal and perinatal factors on neonatal electrocardiographic parameters, including a more left-shifted QRS axis and increased QT duration, although the variation was within normal reference ranges. Our findings add to the knowledge on the neonatal cardiac transition and the cardiac effect of maternal/perinatal factors.

Significance of lipids, lipoproteins, and apolipoproteins during the first 14-16 months of life

BACKGROUND AND AIMS

The aims of this study were to investigate lipid parameters during the first 14-16 months of life, to identify influential factors, and to test whether high concentrations at birth predict high concentrations at 2- and 14-16 months.

METHODS

The Copenhagen Baby Heart Study, including 13,354 umbilical cord blood samples and parallel venous blood samples from children and parents at birth (n = 444), 2 months (n = 364), and 14-16 months (n = 168), was used.

RESULTS

Concentrations of lipids, lipoproteins, and apolipoproteins in umbilical cord blood samples correlated highly with venous blood samples from newborns. Concentrations of low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (HDL) cholesterol, apolipoprotein B, and lipoprotein(a) increased stepwise from birth to 2 months to 14-16 months. Linear mixed models showed that concentrations of LDL cholesterol, non-HDL cholesterol, and lipoprotein(a) above the 80th percentile at birth were associated with significantly higher concentrations at 2 and 14-16 months. Finally, lipid concentrations differed according to sex, gestational age, birth weight, breastfeeding, and parental lipid concentrations.

CONCLUSIONS

Lipid parameters changed during the first 14-16 months of life, and sex, gestational age, birth weight, breastfeeding, and high parental concentrations influenced concentrations. Children with high concentrations of atherogenic lipid traits at birth had higher concentrations at 2 and 14-16 months. These findings increase our knowledge of how lipid traits develop over the first 14-16 months of life and may help in deciding the optimal child age for universal familial hypercholesterolaemia screening.

Electrocardiographic characteristics of newborns with ventricular septal defects: a Copenhagen Baby Heart Study

Ventricular septal defects (VSD) represent the most common congenital heart defect in newborns. We assessed the electrocardiographic characteristics of newborns with VSDs in a general population sample. The Copenhagen Baby Heart Study is a prospective population-based cohort study offering cardiac evaluation of newborns. Echocardiograms and electrocardiograms were obtained within 30 days after birth and systematically analysed. A VSD was identified in 530 newborns (mean age 11 ± 7 days, 42% boys). Newborns with VSDs had a more left-shifted QRS axis (116 ± 34 vs. 120 ± 3°, p = 0.02), and a higher S-wave amplitude in V1 (721 ± 584 vs. 636 ± 549 µV, p = 0.001) than controls. The largest differences were found in newborns with large or perimembraneous VSDs with a higher frequency of left axis deviation, higher S-wave amplitudes in V1, and higher R- and S-wave amplitudes in V6 compared with controls. R-waves in V1 and V6 were significantly associated to left ventricular mass, whereas S-waves in V1 and V6 were dependent on left ventricular end-diastolic diameter on echocardiography.  Conclusion: Newborns with VSDs showed significant differences in QRS axis, and R- and S-wave precordial amplitudes compared to matched controls. Perimembranous and large VSDs had the greatest effect on the neonatal ECG. What is Known: • Ventricular septal defects in newborns are prevalent and may affect cardiac function and structure. What is New: • The Copenhagen Baby Heart Study is the largest study including a cohort of unselected newborns undergoing postnatal cardiac examination. • We found that newborns with VSD showed significant electrocardiographic differences depending on size and type of VSD compared with healthy newborns.

Atrial Septal Defect: Larger Right Ventricular Dimensions and Atrial Volumes as Early as in the First Month After Birth-a Case-Control Study Including 716 Neonates

Atrial septal defect (ASD) is characterized by a left-to-right shunt causing dilatation of the right atrium and right ventricle as well as pulmonary hyperperfusion. The detection of ASDs often occurs late in childhood or adulthood. Little is known about cardiac structure and function in neonates with ASD.We analyzed neonatal echocardiograms from the Copenhagen Baby Heart Study, a multicenter, population-based cohort study of 27,595 neonates. We included 716 neonates with secundum-type ASDs and matched them 1:1 on sex and age at examination with neonates without ASD from the same birth cohort. Neonates with an ASD (median age 11 days, 52% female) had larger right ventricular (RV) dimensions than matched controls (RV longitudinal dimension end-diastole: 27.7 mm vs. 26.7 mm, p < 0.001; RV basal dimension end-diastole: 14.9 mm vs. 13.8 mm, p < 0.001; and RV outflow tract diameter 13.6 mm vs. 12.4 mm, p < 0.001). Atrial volumes were larger in neonates with ASD compared to controls (right atrial end-systolic volume: 2.9 ml vs. 2.1 ml, p < 0.001; and left atrial end-systolic volume 2.0 ml vs. 1.8 ml, p < 0.001). Tricuspid annular plane systolic excursion was larger in neonates with ASD than in controls (10.2 mm vs. 9.6 mm, p < 0.001). Left ventricular dimensions and function did not differ between neonates with ASD and controls. In conclusion, ASDs were associated with altered cardiac dimensions already in the neonatal period, with larger right ventricular dimensions and larger atrial volumes at echocardiography within the first 30 days after birth.ClinicalTrials.gov Identifier: NCT02753348 (April 27, 2016).

A novel algorithm for classification of interatrial communications within the oval fossa in the newborn

BACKGROUND

An interatrial communication is present in most neonates. The majority are considered the "normal" patency of the oval foramen, while a minority are abnormal atrial septal defects. Differentiation between the two with transthoracic echocardiography may be challenging, and no generally accepted method of classification is presently available. We aimed to develop and determine the reliability of a new classification of interatrial communications in newborns.

METHODS AND RESULTS

An algorithm was developed based on echocardiographic criteria from 495 newborns (median age 11[8;13] days, 51.5% females). The algorithm defines three main categories: patency of the oval foramen, atrial septal defect, and no interatrial communication as well as several subtypes. We found an interatrial communication in 414 (83.6%) newborns. Of these, 386 (93.2%) were categorised as patency of the oval foramen and 28 (6.8%) as atrial septal defects.Echocardiograms from another 50 newborns (median age 11[8;13] days, 36.0% female), reviewed by eight experts in paediatric echocardiography, were used to assess the inter- and intraobserver variation of classification of interatrial communications into patency of the oval foramen and atrial septal defect, with and without the use of the algorithm. Review with the algorithm gave a substantial interobserver agreement (kappa = 0.66), and an almost perfect intraobserver agreement (kappa = 0.82). Without the use of the algorithm, the interobserver agreement between experienced paediatric cardiologists was low (kappa = 0.20).

CONCLUSION

A new algorithm for echocardiographic classification of interatrial communications in newborns produced almost perfect intraobserver and substantial interobserver agreement. The algorithm may prove useful in both research and clinical practice.

Cardiac findings in newborn twins

AIMS

To evaluate cardiac findings in newborn twins from the general population and investigate if newborn twins may require systematic evaluation of cardiac parameters.

METHODS

Prospective cohort study of newborns with cardiac evaluation performed during the first month of life. Cardiac findings were compared 1:3 with matched singletons.

RESULTS

We included 412 newborn twins (16% monochorionic; 50% boys) and 1236 singletons. Comparing cardiac findings showed twins had an increased prevalence of non-severe structural heart disease (most common: ventricular septal defects in both groups), thinner left ventricular posterior wall in diastole (LVPWd; 1.82 vs. 1.87 mm, p = 0.02), smaller diameter of the left atrium (10.6 vs. 11.1 mm, p = 0.04), higher heart rate (148 vs. 144 bpm, p = 0.04), more left-shifted QRS axis (106 vs. 111°, p < 0.001), and lower maximum R-wave amplitude in V1 (927 vs. 1015 μV, p = 0.02) compared to singletons. After multifactorial adjustment for potential confounders, the effect of twinning on cardiac parameters persisted only for LVPWd (p < 0.05).

CONCLUSION

Despite contemporary surveillance, we found an increased prevalence of non-severe structural heart disease in a population-based cohort of newborn twins. However, the effect of twinning on cardiac parameters was modest and generally did not persist after correction for likely confounding factors.

The Wolff-Parkinson-White pattern in neonates: results from a large population-based cohort study

AIMS

Wolff-Parkinson-White (WPW) syndrome is a conduction disorder characterized by an accessory electrical pathway between the atria and ventricles, which may predispose to supraventricular tachycardia (SVT) and sudden cardiac death. It can be seen as an isolated finding or associated with structural heart disease. Our aims were to determine the prevalence of a WPW pattern in a large and unselected cohort of neonates and to describe the electro- and echocardiographic characteristics as well as the natural history during early childhood.

METHODS AND RESULTS

Electrocardiograms and echocardiograms of neonates (aged 0-30 days) from a large, prospective, population-based cohort study were included. Neonates with a WPW pattern were identified and matched 1:4 to controls. Localization of the accessory pathway was assessed by different algorithms. Among 17 489 neonates, we identified 17 (76% boys) with a WPW pattern consistent with a prevalence of 0.1%. One neonate had moderate mitral regurgitation while other echocardiographic parameters were similar between cases and controls (all P > 0.05). The accessory pathways were primarily predicted to be left-sided. At follow-up (available in 14/17 children; mean age 3.2 years) the pre-excitation pattern persisted in only four of the children and none of the children had experienced any episodes of SVT.

CONCLUSION

The prevalence of a WPW pattern in our cohort of unselected neonates was 0.1%. The WPW pattern was more frequent in boys and generally not associated with structural heart disease, and the accessory pathways were primarily left-sided. At follow-up, the WPW pattern had disappeared in most of the children suggesting either an intermittent nature or that normalization occurs.

CLINICAL TRIAL REGISTRATION

Copenhagen Baby Heart, NCT02753348.

Age-Related Prevalence of Open Ductus Arteriosus in Full-Term Newborns

BACKGROUND

The ductus arteriosus is part of the fetal circulation. Normally, the vessel closes during the cardiac transition. Delayed closure is associated with complications. The aim of this study was to evaluate the age-related prevalence of open ductus arteriosus in full-term neonates.

METHODS

Echocardiograms were collected in the population study, the Copenhagen Baby Heart Study. The present study included full-term neonates with an echocardiogram performed within 28 days after birth. All echocardiograms were reviewed to assess ductus arteriosus patency.

RESULTS

A total of 21,649 neonates were included. In neonates examined at day zero and day seven, an open ductus arteriosus was found in 36% and 0.6%, respectively. Beyond day seven, the prevalence remained stable at 0.6%.

CONCLUSION

More than one-third of full-term neonates had an open ductus arteriosus on the first day of life, declining rapidly within the first week and stabilizing below 1% after day seven.

Normative Echocardiographic Left Ventricular Parameters and Reference Intervals in Infants

BACKGROUND

In pediatric echocardiography, reference intervals are required to distinguish normal variation from pathology. Left ventricular (LV) parameters are particularly important predictors of clinical outcome. However, data from healthy newborns are limited, and current reference intervals provide an inadequate approximation of normal reference ranges.

OBJECTIVES

Normative reference intervals and z-scores for 2-dimensional echocardiographic measurements of LV structure and function based on a large group of healthy newborns were developed.

METHODS

The study population included 13,454 healthy newborns from the Copenhagen Baby Heart Study who were born at term to healthy mothers, had an echocardiogram performed within 30 days of birth, and did not have congenital heart disease. To develop normative reference intervals, this study modeled 10 LV parameters as a function of body surface area through joint modeling of 4 statistical components.

RESULTS

Infants in the study population (48.5% were female) had a median body surface area of 0.23 m² (IQR: 0.22-0.25 m²) and median age of 12.0 days (IQR: 8.0-15.0 days) at examination. All normative reference intervals performed well in both sexes without stratification on infant sex. In contrast, creation of separate reference models for infants examined at <7 days of age and those examined at 7-30 days of age was necessary to optimize the performance of the reference intervals.

CONCLUSIONS

This study provides normative reference intervals and z-scores for 10 clinical, widely used echocardiographic measures of LV structure and function based on a large cohort of newborns. These results provide highly needed reference material for clinical application by pediatric cardiologists.

Abstract 18: Impact of Preeclampsia on Cardiovascular Risk Factors in Mothers and Newborns

Introduction: Preeclampsia is a multifactorial disease and a cause of maternal and neonatal morbidity and mortality. Women with preeclampsia have increased risk of cardiovascular diseases in later life. The impact on the offspring is, however, still uncertain. Lipid traits in newborns are considered to reflect the child’s own production.

Hypothesis: We assessed the hypothesis that preeclampsia increases risk of future cardiovascular disease in both mother and offspring.

Methods: For this purpose, we used the Copenhagen General Population Study comprising 59,571 women of which 1,365 had a diagnosis of preeclampsia to investigate the association between preeclampsia and risk of cardiovascular diseases. Further, we used the Copenhagen Baby Heart Study comprising more than 13,000 umbilical cord blood samples and assessed the impact of preeclampsia on atherogenic lipid traits in cord blood.

Results: Age adjusted hazard ratios for preeclampsia versus no preeclampsia (95% CI) were 1.48 (1.13-1.94) for ischemic heart disease, 1.50 (1.07-2.12) for ischemic cerebrovascular disease, and 1.53 (1.22-1.91) for composite vascular disease. Corresponding multivariable adjusted hazard ratios (95% CI) were 1.31 (1.00-1.72), 1.44 (1.02-2.02), and 1.39 (1.11-1.74). Concentrations of non-HDL cholesterol, total cholesterol, LDL cholesterol, apolipoprotein B, and triglycerides in cord blood increased stepwise from no preeclampsia (n=11,221) to mild/moderate preeclampsia (n=253) to severe preeclampsia (n=104) (p for trends <0.0001 for non-HDL cholesterol, total cholesterol and LDL cholesterol; p for trend=0.0002 for apolipoprotein B; p for trend=0.003 for triglycerides). Multivariable adjusted odds ratios (95% CI) for preeclampsia versus no preeclampsia (reference) for cord blood concentrations above the 80 th percentile were 2.09 (1.67-2.61) for non-HDL cholesterol, 1.58 (1.25-2.01) for total cholesterol, 1.72 (1.37-2.16) for LDL cholesterol, 1.38 (1.07-1.78) for apolipoprotein B, and 2.64 (2.07-3.35) for triglycerides.

Conclusion: Women with preeclampsia had increased risk of future cardiovascular disease and lipid traits in umbilical cord blood of their offspring were elevated. This indicates that preeclampsia affects lipid metabolism during fetal life and potentially contributes to an increased risk of future cardiovascular disease in offspring of mothers with preeclampsia.

Red blood cell parameters in early childhood: a prospective cohort study

OBJECTIVES

Red blood cell parameters are frequently used biomarkers when assessing clinical status in newborns and in early childhood. Cell counts, amounts, and concentrations of these parameters change through gestation and after birth. Robust age-specific reference intervals are needed to optimize clinical decision making.

METHODS

The Copenhagen Baby Heart Study (CBHS) and the COMPARE study are prospective cohort studies including red blood cell parameters from 7,938 umbilical cord blood samples and 295 parallel venous blood samples from newborns with follow-up at two and at 14-16 months after birth.

RESULTS

For venous blood at birth, reference intervals for hemoglobin, erythrocytes, and hematocrit were 145-224 g/L, 4.1-6.4 × 10¹²/L, and 0.44-0.64, respectively. Hemoglobin, erythrocytes, and hematocrit were lower at birth in children delivered by prelabor cesarean section compared to vaginal delivery. Conversion algorithms based on term newborns were: venous hemoglobin=(umbilical cord hemoglobin-86.4)/0.39; venous erythrocytes=(umbilical cord erythrocytes-2.20)/0.44; and venous hematocrit=(umbilical cord hematocrit-0.24)/0.45.

CONCLUSIONS

This study presents new reference intervals for red blood cell parameters in early childhood, describes the impact of delivery mode, and provide exact functions for converting umbilical cord to venous blood measurements for term newborns. These findings may improve clinical decision making within neonatology and infancy and enhance our clinical understanding of red blood cell parameters for health and diseases in early life.

Markers of Kidney Function in Early Childhood and Association With Maternal Comorbidity

IMPORTANCE

Kidney functional capacity is low at birth but doubles during the first 2 weeks of life and reaches near-adult levels at age 1 to 2 years. Existing reference intervals for markers of kidney function in newborns are mostly based on preterm newborns, newborns with illness, or small cohorts of term newborns, and the consequences of maternal comorbidities for newborn kidney function are sparsely described.

OBJECTIVE

To establish robust reference intervals for creatinine and urea in healthy children in early childhood and to assess whether maternal comorbidity is associated with newborn creatinine and urea concentrations.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, prospective, population-based cohort study assessed data and umbilical cord blood samples from participants in the Copenhagen Baby Heart Study (CBHS) who were born between April 1, 2016, and October 31, 2018, and venous blood samples from a subsample of CBHS participants who were enrolled in the COMPARE study between May 3, 2017, and November 4, 2018. Cord blood samples of 13 354 newborns from the CBHS and corresponding venous blood samples of 444 of those newborns from the COMPARE study were included. Blood samples were collected at birth, age 2 months, and age 14 to 16 months, with follow-up completed on February 12, 2020. Healthy nonadmitted term newborns from maternity wards at 3 hospitals in the Capital Region of Denmark were included.

EXPOSURES

Maternal comorbidity.

MAIN OUTCOMES AND MEASURES

Creatinine and urea concentrations.

RESULTS

Among 13 354 newborns in the CBHS cohort, characteristics of 12 938 children were stratified by sex and gestational age (GA). Of those, 6567 children (50.8%) were male; 5259 children (40.6%) were born at 37 to 39 weeks' GA, and 7679 children (59.4%) were born at 40 to 42 weeks' GA. Compared with children born at 40 to 42 weeks' GA, those born at 37 to 39 weeks' GA had lower birth weight, Apgar scores at 5 minutes, placental weight, and placental-fetal weight ratio. Children born at 37 to 39 weeks' GA vs those born at 40 to 42 weeks' GA were more frequently small for GA at birth and more likely to have placental insufficiency and exposure to maternal preeclampsia, maternal diabetes, maternal kidney disease, and maternal hypertension. Among children born at 37 to 39 weeks' GA, reference intervals were 0.54 to 1.08 mg/dL for creatinine and 5.32 to 14.67 mg/dL for urea; among children born at 40 to 42 weeks' GA, reference intervals were 0.57 to 1.19 mg/dL for creatinine and 5.60 to 14.85 mg/dL for urea. At birth, multifactorially adjusted odds ratios among children exposed to preeclampsia were 9.40 (95% CI, 1.68-52.54) for a venous creatinine concentration higher than the upper reference limit, 4.29 (95% CI, 1.32-13.93) for a venous creatinine concentration higher than the 90th percentile, and 3.10 (95% CI, 1.14-8.46) for a venous creatinine concentration higher than the 80th percentile.

CONCLUSIONS AND RELEVANCE

In this study, improved reference intervals for creatinine and urea concentrations were generated. Preeclampsia was associated with an increased risk of high newborn creatinine concentrations, suggesting that newborns of mothers with preeclampsia need closer observation of their kidney function.

Impact of maternal risk factors on the structure and function of the heart in newborns

Introduction

Maternal factors such as smoking during pregnancy, advanced age, and obesity are associated with increased risk of complex congenital heart defects in the offspring. It is unknown whether maternal risk factors may also cause subtle abnormalities in cardiac structure and function.

Purpose

To investigate whether the following maternal factors: advanced age, high body mass index (BMI), and smoking during pregnancy are associated with changes in left ventricle (LV) dimensions and systolic function in the newborn child.

Methods

Data was obtained as part of a population-based cohort study with prenatal inclusion and postnatal transthoracic echocardiography (TTE) of newborns within 60 days of birth. The TTE protocol included measurements of: Interventricular septal thickness at end-diastole (IVSd), LV posterior wall thickness at end-diastole (LVPWd), LV internal diameter at end-diastole (LVIDd) and LV internal diameter at end-systole (LVIDs). Fractional shortening (FS) was calculated by use of Teicholz's formula.

Children of mothers with data available on age, BMI, and smoking status, respectively, were divided into the following groups depending on whether their mothers were: of young age &lt;25 years, 25–29 years, 30–34 years (reference group), 35–39 years, and advanced age ≥40 years; underweight BMI &lt;18.5, normal range BMI 18.5–24.9 (reference group), preobese BMI 25–29.9, and obese BMI ≥30; smoking or nonsmoking (reference group).

Associations between different groups with each maternal risk factor and newborn LV parameters were analysed using a multiple linear regression model.

Results

Children of mothers with advanced age at the time of childbirth (n=1,411) had significantly smaller LVIDd and LVIDs (Table 1) compared to children of mothers in their early thirties (n=10,045). Children of preobese (n=4,707) and obese mothers (n=2,138) had significantly smaller LVIDd and LVIDs than children of mothers in the normal BMI range (n=17,654). Children of mothers who smoked during pregnancy (n=808) had significantly larger LVPWd than children of non-smoking mothers (n=24,072). A significant difference in FS was only seen in children of obese mothers.

Subanalyses of the quantity of maternal smoking (available data in n=548 [67.8%] of mothers who smoked during pregnancy) showed that children of heavy smoking mothers (≥15 cigarettes/day, n=101), had significantly thicker IVSd and LVPWd compared with children of nonsmoking mothers, whereas no significant effect was identified in newborns of mothers smoking less than 15 cigarettes per day (Table 2).

Conclusions

Systematic population-based echocardiography of newborns showed that an increased maternal BMI and maternal age above 40 years were associated with smaller LV cavity dimensions in the offspring and that heavy smoking during pregnancy was associated with increased LV myocardial thickness. FS was only affected in children of obese mothers. The long-term effects of these novel findings are unknown.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Herlev-Gentofte Hospital Internal Funding for Cardiological Research andThe Novo Nordisk Foundation

Maternal pre-existing diabetes and gestational diabetes and the prevalence of septal defects in the offspring

Background and introduction

Maternal pre-existing and gestational diabetes affect approximately 6% of all pregnancies in Denmark and are well known risk factors for congenital heart disease (CHD). Worldwide, CHD is the most common congenital defect and a leading cause of infant death. The association between maternal diabetes, and CHD in the offspring has previously been studied, however, these studies have been limited by small study cohorts and/or registry studies without systematic transthoracic echocardiography (TTE) of the children.

Purpose

To assess the prevalence of atrial and ventricular septal defects (ASD and VSD) in children born to mothers with pre-existing or gestational diabetes by systematic TTE, in a large, population-based cohort of neonates.

Method

Systematic, standardized TTE was performed in neonates included in a population-based cohort study between 2016 and 2018. For the present study, the prevalence of VSD in cases and controls was assessed in the entire cohort of neonates who underwent TTE within 30 days of birth, and in whom information regarding maternal diabetes was available (n=24,921). The prevalence of ASD was assessed in a sub-cohort of neonates (n=12,682) with the same inclusion criteria and in whom an interatrial communication had been classified as ASD or patent oval foramen according to a validated algorithm. ASD was defined as an interatrial communication with a defect size ≥4mm, a location in the inferior 1/3 of septum, or multiple communications. VSD was defined as flow across the interventricular septum in colour Doppler mode in one or more views. VSDs were classified as either muscular, perimembranous, or subarterial.

Information about maternal pre-existing and gestational diabetes was collected from review of the mother's medical records and from an Obstetrical Database maintained by the participating hospitals.

Cases were compared with controls, which here consists of the full cohort for VSD and sub-cohort for ASD, respectively, after excluding cases.

Results

The median age at examination of the entire cohort was 11 days [interquartile range (IQR) 7; 14] and 48% were female.

The prevalence of VSD in children with maternal diabetes was 3.1% compared with 3.3% among children of mothers without maternal diabetes, RR 1.00 (95% CI 0.99–1.01, p=0.771). There was no difference between cases and controls when comparing the prevalence of subtypes of VSD (table 1).

In the sub-cohort of 12,682 neonates assessed for ASD (median age at examination 12 days [IQR, 8; 15], 48% female), the presence of an ASD was found in 7.3% of cases compared to 5.9% among controls, RR 0.81 (95% CI 0.59–1.13, p=0.214).

Conclusion

In a large population-based cohort of infants, we did not find an increased risk for ASD or VSD, nor any of the subtypes of VSD, among children born to mothers with pre-existing or gestational diabetes as compared to controls.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): The Capital Region of Denmarks Research Fund.The Research Council of Herlev and Gentofte Hospital.

Left ventricular non-compaction in childhood: echocardiographic follow-up and prevalence in first-degree relatives

Introduction

Left ventricular non-compaction (LVNC) is characterized by excessive trabeculations of the left ventricular wall. LVNC may be associated with reduced systolic function but is also found in individuals with normal ventricular function. It is debated whether LVNC is only congenital or may develop later in life. The clinical importance and heredity of LVNC with normal systolic function is unclear.

Purpose

We aimed to describe the echocardiographic development of the left ventricular function and LVNC pattern in children with LVNC, diagnosed at birth, at follow-up at the age of 2–4 years compared to matched controls. Additionally, we aimed to describe the prevalence of LVNC in first-degree relatives.

Methods

A follow-up transthoracic echocardiography was performed in children at 2–4 years of age, diagnosed with LVNC at birth (&lt;30 days) as part of a large population study of newborns (n&gt;25,000). Cases were matched 1:4 to controls on mother's age at delivery, parity, and age of the child at follow-up. First-degree relatives (parents, siblings and half-siblings) of cases and controls were also offered inclusion. LVNC was defined as a ratio of non-compact to compact myocardium of ≥2 in at least one left ventricular segment measured in end-diastole perpendicular to the left ventricular cavity.

Results

13 of the 16 children diagnosed with LVNC at birth (median age 3 (interquartile range (IQR) 3–4) years, 77% male) and 52 children without LVNC at birth (age 4 (IQR 3–4) years, 88% male) was reevaluated as well as 36 first-degree relatives of children with LVNC (age 30 (IQR 4–37) years, 44% male) and 136 first-degree relatives of children without LVNC (age 32 (IQR 10–38) years, 50% male). In probands, the number of segments fulfilling criteria (8% vs. 13%, p=0.4) and systolic function, measured as fractional shortening (FS), were unchanged from birth to follow-up, and within normal range (29% vs. 30%, p=0.34). However, at follow-up, FS was significantly lower in probands compared with matched controls (30% vs. 33%, p&lt;0.001). Criteria of LVNC was fulfilled in 11 out of 36 (31%) first-degree relatives to probands, whereas none of the first-degree relatives of children without LVNC fulfilled criteria of LVNC (p&lt;0.001). FS was significantly lower in first-degree relatives of probands fulfilling criteria of LVNC compared to first-degree relatives of matched controls (30% vs. 32%, p=0.01).

Conclusion

Children with LVNC diagnosed neonatally as part of a population study still had a reduced systolic function when compared to controls but showed no further progression of left ventricular dysfunction or extent of trabeculation at the age of 2–4 years. One third of first-degree relatives to children diagnosed with LVNC with a preserved systolic function, fulfilled criteria for LVNC and had reduced systolic function compared to controls. These findings strongly support family-screening and clinical follow-up of children with LVNC.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Novo Nordisk FoundationHerlev-Gentofte Hospital Internal Funding

Yield of echocardiographic screening of first-degree relatives of children with bicuspid aortic valve

Background

Bicuspid aortic valve (BAV) is the most common congenital heart defect, affecting 0.8% of new-borns. BAV is associated with valve dysfunction, as well as an increased risk of aortopathy. The prevalence of BAV in first-degree relatives of symptomatic BAV patients, is reported to be 5–10%. First-degree relatives also have an increased risk of aortic dilatation, independently of aortic valve morphology.

Purpose

The purpose of the study was to determine the prevalence of BAV, associated valve dysfunction and aortopathy in first-degree relatives to children diagnosed with BAV neonatally in a population-based study.

Methods

Between April 2016 and October 2018 all expecting parents at three major maternity centres were offered inclusion in a large-scale population study with focus on congenital heart disease (N≥25,000). A total of 197 children, in 196 families, were diagnosed with BAV. All first-degree relatives, including half-siblings, were offered inclusion in the follow-up study with standardized transthoracic echocardiography. Adults were also examined with transoesophageal echocardiography. Aorta diameters were measured at the AV annulus, sinuses of Valsalva, sino-tubolare junction and in the proximal ascending aorta. Aortic dilatation in children were defined as any aortic root or ascending aorta diameter ≥2 standard deviations (SD) from the expected mean, calculated as z-score using formulas from the Paediatric Heart Network Echocardiogram Database. In adults, aortic dilatation was defined as aortic root and/or ascending aorta diameters indexed to body surface area (BSA) exceeding normal reference values established by the European Association of Cardiovascular Imaging.

Results

In total, 352 first-degree relatives (242 adults [35.3 years SD 5.5] and 110 children [4.5 years, SD 3.5] were included. BAV was diagnosed in 24 relatives (6.8%). BAV could not be conclusively ruled out in 52 relatives (14.8%), who are awaiting further examination with transoesophageal echocardiography. Dilatation of the aortic root was observed in 8 adult relatives and in 17 children (7.1%). Aortic valve regurgitation was observed in 23 relatives (6.5%). In total 58 relatives (16.2%) were diagnosed with either BAV, dilated aorta, or aortic regurgitation.

Conclusion

One in fifteen first-degree relatives to children diagnosed with BAV neonatally, also had BAV, corresponding to &gt;8 fold increase in prevalence compared with the background population. One in six relatives had BAV, dilated aorta, or aortic regurgitation. These findings are of importance for family-screening programs of BAV.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Danish Children's Heart Association

The impact of perinatal factors on the neonatal electrocardiogram

Background

Myocardial development is still incomplete by the time of birth making the cardiomyocyte vulnerable in the perinatal period. However, little is known on whether perinatal factors affect the neonatal electrocardiogram, and if so, to what degree these effects persist in the neonatal period.

Purpose

To investigate the impact of maternal and perinatal factors on the neonatal electrocardiogram in a large unselected cohort of neonates.

Methods

In a multicentre, prospective, population-based cohort study, neonates underwent cardiac evaluation during the first month of life. Electrocardiograms and echocardiograms were obtained and systematically analysed. Medical and demographic information on the parents, pregnancy, and birth-related factors were registered, and the following perinatal risk factors were evaluated: maternal comorbidities, maternal BMI ≥25, use of assisted reproduction technology, parity, (preterm) premature rupture of membranes, placental disorders, abnormal foetus presentation, induction of labour with synthetic hormone, instrumental induction, administration of nitrous oxide, epidural/spinal administration, labour ≥24h, pushing stage ≥1h, Caesarean section, and instrumental delivery.

Results

A total of 15,928 singletons with normal echocardiograms were included (52% boys; median age at examination 11 days). The neonates were divided into groups by accumulated number of perinatal risk factors: 0 (n=1,587), 1 (n=3,718), 2 (n=4,026), 3–4 (n=4,998), and ≥5 (n=1,197), and differences in ECG parameters between the groups were analysed. Heart rate, QRS axis, uncorrected QT interval, QTcBazett, QTcFridericia, and maximum amplitudes in R-V1 and R-V6 differed across the five subgroups (all p&lt;0.05). We observed a cumulative effect of perinatal risk factors on ECG parameters with increasing left-shift in the QRS axis, prolongation of the QT interval, and increasing amplitudes in R-V1 and R-V6. The subgroup with ≥5 perinatal risk factors differed the most, and absolute differences between this subgroup and neonates without any perinatal risk factors were 7.6% in maximum amplitudes in R-V6 (940 vs. 874 μV, p&lt;0.01), 4.3% in R-V1 (1,201 vs. 1,152 μV, p&lt;0.05), 5.1% in the QRS axis (111 vs 117°, p&lt;0.0001) and 0.8% in QTcFridericia (366 vs. 363 ms, p&lt;0.01).

Conclusion

We observed a cumulative effect of perinatal risk factors including a significantly more left-shifted QRS axis, increased values of the QT interval, and higher amplitudes in R-V1 and R-V6 in the subgroup with ≥5 perinatal risk factors. These findings suggest a relatively lower right ventricular dominance pattern, discrete prolongation of the QT interval and increased myocardial mass of the right ventricle in neonates exposed to multiple perinatal risk factors. However, the absolute differences in ECG parameters were relatively small. These findings may be useful for identification of neonates with increased cardiovascular risk.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Department of Cardiology, Herlev-Gentofte Hospital, Internal Funding

Prevalence of Left Ventricular Noncompaction in Newborns

BACKGROUND

Left ventricular noncompaction (LVNC) is characterized by excessive trabeculations of the LV and may be associated with reduced systolic function or severe adverse outcomes. Several aspects remain to be elucidated; there is controversy to whether LVNC cardiomyopathy is a distinct cardiomyopathy caused by failure of the spongy fetal myocardium to condense during fetal development or acquired later in life as a morphological trait associated with other types of cardiomyopathy; the prevalence in unselected populations is unknown and the distinction between normal variation and pathology remains to be defined. In this study, we aimed to determine the prevalence of LVNC and the association to LV systolic function in a large, population-based cohort of neonates. In addition, we assessed the normal ratio of noncompact to compact (NC:C) myocardium in 150 healthy neonates.

METHODS

Echocardiographic data were prospectively collected in the population study Copenhagen Baby Heart Study. The ratio of NC:C was measured in 12 ventricular segments. LVNC was defined as NC:C ≥2 in at least one segment. Neonates with LVNC were matched 1:10 to controls on sex, gestational age, and weight and age at the examination day.

RESULTS

In total, 25 590 neonates (52% males, median age 11 [interquartile range, 7-15] days) underwent echocardiography. Among 21 133 with satisfactory visualization of ventricular segments, we identified a prevalence of LVNC of 0.076% (95% CI, 0.047-0.123). LV ejection fraction was lower in neonates with LVNC compared with matched controls (median 49.5 versus 59.0%; P<0.0001). In neonates with otherwise healthy hearts, the median NC:C ratio ranged from 0.0 to 0.7 and the 99th percentiles from 1.0 to 1.9 for each of the 12 segments.

CONCLUSIONS

The prevalence of LVNC based on neonatal echocardiography was 0.076%. LVNC was associated with lower LV systolic function. The findings in normal newborns support the cutoff NC:C ≥2 as an appropriate diagnostic criterion.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02753348.

Defining the normal QT interval in newborns: the natural history and reference values for the first 4 weeks of life

AIMS

Evaluation of the neonatal QT interval is important to diagnose arrhythmia syndromes and evaluate side effects of drugs. We aimed at describing the natural history of the QT interval duration during the first 4 weeks of life and to provide reference values from a large general population sample.

METHODS AND RESULTS

The Copenhagen Baby Heart Study is a prospective general population study that offered cardiac evaluation of newborns. Eight-lead electrocardiograms were obtained and analysed with a computerized algorithm with manual validation. We included 14 164 newborns (52% boys), aged 0-28 days, with normal echocardiograms. The median values (ms, 2-98%ile) for the corrected intervals QTc (Bazett), QTc (Hodges), QTc (Fridericia), and QTc (Framingham) were 419 (373-474), 419 (373-472), 364 (320-414), and 363 (327-405). During the 4 weeks, we observed a small decrease of QTcFramingham, and an increase of QTcHodges (both P < 0.01), while QTcBazett and QTcFridericia did not change (P > 0.05). Applying published QT interval cut-off values resulted in 5-25% of the newborns having QT prolongation. Uncorrected QT intervals decreased linearly with increasing heart rate (HR). Sex and infant size did not affect the QT interval and the gestational age (GA) only showed an effect when comparing the extreme low- vs. high GA groups (≤34 vs. ≥42 weeks, P = 0.021).

CONCLUSION

During the 4 weeks QTcFramingham and QTcHodges showed minor changes, whereas QTcBazett and QTcFridericia were stable. The QT interval was unaffected by sex and infant size and GA only showed an effect in very premature newborns. Reference values for HR-specific uncorrected QT intervals may facilitate a more accurate diagnosis of newborns with abnormal QT intervals.

Prevalence of Bicuspid Aortic Valve and Associated Aortopathy in Newborns in Copenhagen, Denmark

IMPORTANCE

The prevalence and characteristics of bicuspid aortic valve (BAV) are mainly reported from selected cohorts. BAV is associated with aortopathy, but it is unclear if it represents a fetal developmental defect or is secondary to abnormal valve dynamics.

OBJECTIVE

To determine the prevalence of BAV and BAV subtypes and to describe the associated aortopathy in a large, population-based cohort of newborns.

DESIGN, SETTING, AND PARTICIPANTS

The Copenhagen Baby Heart Study was a cross-sectional, population-based study open to all newborns born in Copenhagen between April 1, 2016, and October 31, 2018. Newborns with BAV were matched 1:2 to newborns with a tricuspid aortic valve (non-BAV group) on sex, singleton/twin pregnancy, gestational age, weight, and age at time of examination.

EXPOSURES

Transthoracic echocardiography within 60 days after birth.

MAIN OUTCOMES AND MEASURES

Primary outcome was BAV prevalence and types, ie, number of raphes and spatial orientation of raphes or cusps (no raphes), according to the classification system of Sievers and Schmidtke (classified as type 0, 1, or 2, with numbers indicating the number of raphes). Secondary outcome was valve function and BAV-associated aortopathy, defined as aortic diameter z score of 3 or greater or coarctation.

RESULTS

In total, 25 556 newborns (51.7% male; mean age, 12 [SD, 8] days) underwent echocardiography. BAV was diagnosed in 196 newborns (prevalence, 0.77% [95% CI, 0.67%-0.88%]), with male-female ratio 2.1:1. BAV was classified as type 0 in 17 newborns (8.7% [95% CI, 5.5%-13.5%]), type 1 in 178 (90.8% [95% CI, 86.0%-94.1%]) (147 [75.0% {95% CI, 68.5%-80.5%}] right-left coronary raphe, 27 [13.8% {95% CI, 9.6%-19.3%}] right coronary-noncoronary raphe, 4 [2.0% {95% CI, 0.8%-5.1%}] left coronary-noncoronary raphe), and type 2 in 1 (0.5% [95% CI, 0.1%-2.8%]). Aortic regurgitation was more prevalent in newborns with BAV (n = 29 [14.7%]) than in those without BAV (1.3%) (absolute % difference, 13.4% [95% CI, 7.8%-18.9%]; P < .001). Newborns with BAV had higher flow velocities across the valve (0.67 [95% CI, 0.65-0.69] m/s vs 0.61 [95% CI, 0.60-0.62] m/s; mean difference, 0.06 m/s [95% CI, 0-0.1]) and larger aortic root and tubular ascending aortic diameters than those without BAV (10.7 [95% CI, 10.7-10.9] mm vs 10.3 [95% CI, 10.2-10.4] mm; mean difference, 0.43 mm [95% CI, 0.2-0.6 mm] and 9.8 [95% CI, 9.6-10.0] mm vs 9.4 [95% CI, 9.3-9.5] mm; mean difference, 0.46 mm [95% CI, 0.30-0.70], respectively) (P < .001 for all). Aortopathy was seen in 65 newborns (33.2%) with BAV (62 with aortic z score ≥3; 3 with coarctation).

CONCLUSIONS AND RELEVANCE

Among newborns in Copenhagen, the prevalence of BAV was 0.77%. Aortopathy was common in newborns with BAV, suggesting that it also represents a fetal malformation.

P2735Ventricular function in a large cohort of healthy, term newborns assessed by tissue doppler imaging and speckle tracking echocardiography; establishment of normal values and z-scores

Background

There is a paucity of published data presenting reference values for ventricular function in newborns.

Purpose

This study was conducted to establish echocardiographic normal data and z-scores for ventricular functional parameters in newborns assessed by Tissue Doppler Imaging (TDI) and Speckle Tracking Echocardiography (STE).

Methods

We included healthy, term newborns from a prospective, population-based study of newborns, who had a comprehensive, systematic echocardiographic (TTE) examination performed within 14 days of birth. Only newborns without any signs of structural or functional cardiac abnormalities were included. Measurements were obtained according to guidelines. Body surface area (BSA) was calculated using the Haycock formula. Z-score models according to birthweight and BSA at time of TTE were developed for TDI and STE parameters.

Results

Four hundred newborns (53% male) with gestational age of (median (IQR)) 40.3 (39.4, 41.1) weeks were included. Age, weight, and BSA at TTE were (mean±SD) 11±3 days, 3.7±0.5 kg, and 0.23±0.02m2, resp. Ejection fraction was 67±4%. TDI and STE measurements of ventricular function are presented as mean±SD (Table). Global longitudinal strain was calculated as the average of all left ventricular segmental strain values from apical 4-, 2-, and 3-chamber views. Results for selected parameters according to BSA are illustrated (Figure).

TDI and STE of ventricular function Parameter View and modality Value Unit Mitral annulus septal wall e' Apical 4-chamber Tissue Doppler 5.7±0.8 cm/s Mitral annulus septal wall a' Apical 4-chamber Tissue Doppler 5.9±1.0 cm/s Mitral annulus septal wall s' Apical 4-chamber Tissue Doppler 4.6±0.6 cm/s Mitral annulus lateral wall e' Apical 4-chamber Tissue Doppler 6.9±1.0 cm/s Mitral annulus lateral wall a' Apical 4-chamber Tissue Doppler 6.0±1.1 cm/s Mitral annulus lateral wall s' Apical 4-chamber Tissue Doppler 4.8±0.6 cm/s Left ventricular longitudinal strain, 4-chamber Apical 4-chamber 2D 19±2 % Left ventricular longitudinal strain, 2-chamber Apical 2-chamber 2D 20±2 % Left ventricular longitudinal strain, 3-chamber Apical 3-chamber 2D 19±2 % Left ventricular global strain 19±2 % Right ventricular longitudinal strain, free wall Apical 4-chamber 2D 23±4 %

Percentile charts

Conclusion

Normal data for TDI and STE assessment of ventricular function in 400 healthy, term newborns ispresented. An online z-score calculator will be available. Normal data is necessary for the evaluation of pathological changes, and these results contribute substantially to a field where available data is limited.

Acknowledgement/Funding

Danish Heart Association, Danish Children's Heart Foundation, Candy's Found., Toyota Found., Herlev-Gentofte Hospital Research Found., Gangsted Found.

P3441Impact of maternal preeclampsia on left ventricular structure and function in the newborn heart

Background

Maternal preeclampsia (PE) has been associated with an increased risk of a variety of congenital heart defects in the infant. Whether PE also confers an increased risk of subtle structural and functional cardiac deficits is unknown.

Purpose

We investigated whether left ventricular dimensions and systolic function differed among infants of mothers with PE, compared to infants born after uncomplicated pregnancies.

Method

Systematic transthoracic echocardiography (TTE) was performed in neonates included in a population-based study in the period 2016–2018 (n=25,000). TTE was preferably performed within 14 days of birth. Left ventricular (LV) posterior wall end-diastolic thickness (LVPWd), interventricular septum end-diastole thickness (IVSd), LV internal diameter in end-diastole and end-systole (LVIDd and LVIDs), LV ejection fraction (LVEF) and fractional shortening (FS) were assessed. Information on maternal PE (ICD-10 codes DO140–142 and DO159) was retrieved from an obstetric database. Using linear regression in a sample of echocardiograms, we compared the LV structure and function adjusted for maternal age; gestational age; sex; weight and length.

Results

In total, 447 infants were exposed to PE, and 7,178 were born to uncomplicated pregnancies (Table). In infants of PE mothers, we found significantly larger LVPWd and IVSd (0.18 mm, 95% CI [0.14; 0.22], p<0.001 and 0.06 mm, 95% CI [0.02; 0.10], p=0.001, resp.) and LVIDd as LVIDs were significantly smaller (−0.15 mm, 95% CI [−0.29; −0.01], p=0.032 and −0.16 mm 95% CI [−0.28; −0.04], p=0.009, resp.) compared to infants of non-PE mothers. We found no differences in systolic function.

LV measures in PE and non-PE infants Parameter Infants of PE mothers, Infants of non-PE mothers, p-value Estimate* [95% CI] p-value mean [± SD] (n=447) mean [± SD] (n=7,178) Left Ventricular Posterior Wall in end-Diastole, LVPWd (mm) 2.20 [±0.58] 2.07 [±0.40] <0.001 0.18 [0.14; 0.22] <0.001 Interventricular Septum in end-Diastole, IVSd (mm) 2.53 [±0.52] 2.55 [±0.41] 0.562 0.06 [0.02; 0.10] 0.001 Left Ventricular Internal Diameter in end-Diastole, LVIDd (mm) 19.35 [±2.00] 20.10 [±1.41] <0.001 −0.15 [−0.29; −0.01] 0.032 Left Ventricular Internal Diameter in end-Diastole, LVIDs (mm) 13.13 [±1.43] 13.65 [±1.79] <0.001 −0.16 [−0.28; −0.04] 0.009 Fractional Shortening, FS (%) 32.10 [±4.07] 32.11 [±3.86] 0.937 0.26 [−0.11; 0.63] 0.168 Left Ventricular Ejection Fraction, LVEF (%) 63.19 [±5.61] 63.09 [±5.30] 0.690 0.34 [−0.17; 0.85] 0.192 *Adjusted for maternal age; gestational age; sex; weight and length.

Conclusion

In the largest population-based group of neonates to date, we showed that infants born to PE mothers compared to infants of non-PE mothers had significantly thicker left ventricular myocardium, and reduced left ventricular volumes. However, PE was not associated with altered systolic function. Our results might reflect an adaption of the fetal heart to the increased resistance in the placental arteries in PE mothers, and a secondary increased left ventricular afterload.

Acknowledgement/Funding

Danish Heart Association, Danish Children's Heart Foundation, Candy's Found., Toyota Found., Herlev-Gentofte Hospital Research Found., Lundbeck Found.

Maximum carotid artery wall thickness and risk factors in a young primary prevention population

Maximum carotid artery wall thickness was utilized in a primary prevention population and compared with baseline risk factors. Carotid wall thickness was measured between the blood-intima and media-adventitia interfaces by B-mode ultrasonography using software calipers at points of protrusion. Long-axis measures were confirmed by short-axis assessment. The maximum carotid wall thickness for each subject was divided by age in years to yield an annual accretion rate (called carotid intima-media thickness accretion rate [CIMTAR]). The entire study population was then divided by median CIMTAR to investigate the association with baseline variables used in standard risk assessments with the bifurcated groups. Traditional risk factors such as age, diabetes, smoking, hyperlipidemia, and obesity were not associated with greater than median CIMTAR. Only male gender (P = 0.02) and systolic blood pressure (P = 0.002) in baseline variables were associated with an elevated CIMTAR for the entire population. Among those not taking lipid-lowering therapy at baseline, only systolic blood pressure remained significant (P = 0.0002). Correlations between low-density lipoprotein (LDL) cholesterol level and maximum carotid wall thickness/CIMTAR were weak for the entire population (r = -0.17/r = -0.12, respectively). Measure of maximum carotid wall thickness may select patients earlier for treatment than traditional risk factors. The addition of CIMTAR to risk algorithms may permit a single-point assignation of subsequent vascular risk that is more efficacious than traditional risk factors.