Screening for Critical Congenital Heart Defects in Sweden.

OBJECTIVES: Early diagnosis of critical congenital heart defects (CCHD) improves survival. We evaluated the relative contributions of prenatal ultrasound, neonatal pulse oximetry screening (POS), and neonatal physical examination (NPE) to the early detection (before discharge) of CCHD in the context of increasing prenatal detection, and POS being a national standard since 2013. METHODS: Retrospective, nationwide population-based study. All full-term live-born infants with CCHD in Sweden between 2014 and 2019 were included. CCHD was defined as a congenital heart defect requiring surgery or catheter-based intervention or resulting in death within 28 days of birth. RESULTS: Of 630 infants, 89% were diagnosed before discharge or death, 42% prenatally, 11% from early symptoms, 23% by POS, and 14% from NPE after a negative POS. Four (0.6%) died undiagnosed before discharge and 64/630 (10%) were discharged undiagnosed, with 24/64 being readmitted with circulatory failure and causing 1 preoperative death. Coarctation was the most prevalent CCHD (N = 184), 25% of whom were detected prenatally (12% by POS and 29% by NPE). Two died undiagnosed before discharge and 30% were discharged undiagnosed. Transposition was the second most common defect (N = 150) and 43% were detected prenatally (33% by POS, 1 by NPE) and 2 died undiagnosed before POS. None was discharged undiagnosed. CONCLUSIONS: POS and NPE remain important for the early detection of CCHD complementing prenatal ultrasound screening. Nevertheless, 1 in 10 with CCHD leaves the hospital without a diagnosis, with coarctation being the predominant lesion. Future research on CCHD screening should have a particular focus on this cardiac defect.

Low false-positive rate of perfusion index as a screening tool for neonatal aortic coarctation.

AIM: Adding perfusion index (PI) to pulse oximetry screening (POS) may increase neonatal detection of CoA (aortic coarctation). A cut-off <0.7% has been suggested but is associated with a high rate of false positives. We aimed to evaluate the specificity of PI when using repeated instead of single measurements. METHODS: A pilot study was conducted in 50 neonates. PI was recorded in right hand and a foot by pulse oximeter. If PI was <0.7%, the measurement was immediately repeated up to 3 times. If all three measurements were <0.7% in hand and/or foot the screen was positive and echocardiography was performed. There were 3/50 false-positive screens. The protocol was therefore modified requiring 30 min intervals between measurements. RESULTS: An additional 463 neonates were included using the modified protocol at a median age of 18 h. There were no false positives. The only neonate with CoA had a negative screen (PI hand 1.2% and foot 0.8%). The measurement required on average an extra 3 min and 30 s compared with POS only. CONCLUSION: The false-positive rate of PI was reduced by using repeated PI measurements. The sensitivity for CoA using this protocol should be evaluated in large-scale prospective studies.

Low risk of necrotising enterocolitis in enterally fed neonates with critical heart disease: an observational study.

OBJECTIVE: We aimed to investigate the frequency of necrotising enterocolitis (NEC) in infants with critical congenital heart disease (CCHD) hypothesising that preoperative enteral feeding does not increase the risk of NEC. BACKGROUND: When NEC affects term infants, underlying risk factors such as asphyxia, sepsis or CCHD are often found. Due to fear of NEC development in infants with CCHD great caution is practised in many countries to defer preoperative enteral feeding, but in Sweden this is routinely provided. DESIGN, SETTING AND PATIENTS: An observational study of all infants born with CCHD who were admitted to Queen Silvia Children's Hospital in Gothenburg between 2010 and 2017. The International Classification of Diseases 10th Revision diagnosis code of NEC was used to identify NEC cases in this group. Infants described as 'fully fed' or who were fed at least 45 mL/kg/day before cardiac surgery were identified. MAIN OUTCOME MEASURES: NEC in infants with CCHD in relation to preoperative enteral feeding. RESULTS: There were 458 infants with CCHD admitted during the study period. 408/458 were born at term and 361/458 required prostaglandin E1 before surgery. In total, 444/458 infants (97%) were fully fed or fed at least 45 mL/kg daily before cardiac surgery. Four of 458 infants developed NEC (0.9%). All four had other risk factors for NEC. CONCLUSIONS: This study showed a low risk of NEC in term infants fed enterally before cardiac surgery. We speculate that preoperative enteral feeding of neonates with CCHD does not increase the risk of NEC development.

Coarctation repair normalizes left ventricular function and aorto-septal angle in neonates.

BACKGROUND AND AIMS: Patients with coarctation of the aorta (CoA) have increased left ventricular (LV) afterload that has been shown to impact the LV and ascending aortic function. We aimed to examine the effect of coarctation on LV function and aorto-septal angle (AoSA) before and after surgical repair. METHODS: We retrospectively studied 21 patients with surgically repaired CoA at a median age of 9 (2-53) days at three time points: (1) just before intervention, (2) at short-term follow-up, and (3) at medium-term follow-up after intervention. AoSA was measured from the parasternal long axis view, at three time points during the cardiac cycle: (1) end diastole, (2) beginning of systole, and (3) at peak ejection in the descending aorta. In addition to conventional LV structure and function, global longitudinal strain, and strain rate were measured using STE technique and Tomtec software. Three groups of age matched healthy children served as controls at each time point. RESULTS: AoSA was significantly wider before intervention, in particular at peak ejection in the descending aorta (144° ± 6.4° vs. 136° ± 4.1°; P < .0001), and correlated with CoA pressure gradient. After intervention, AoSA normalized and significantly correlated with the increase of LV cavity function and overall LV deformation parameters. CONCLUSIONS: AoSA is abnormally wide in neonates with CoA and is associated with severity of obstruction, LV dysfunction and compromised LV global deformation.

Persistent reduced myocardial deformation in neonates after CoA repair.

INTRODUCTION: Surgical repair of coarctation of the aorta (CoA) is a safe procedure in children, however the condition is known for its potential recurrence and other related complications. The available evidence shows abnormal intrinsic properties of the aorta in CoA, thus suggesting additional effect, even after CoA repair, on left ventricular (LV) function. Accordingly, we sought to obtain a better understanding of LV myocardial mechanics in very early-corrected CoA using two-dimensional STE. METHODS AND RESULTS: We retrospectively studied 21 patients with corrected CoA at a median age of 9 (2-53) days at three time points: 1) just before intervention, 2) at short-term follow-up and 3) at medium-term follow-up after intervention and compared them with normal values. Speckle tracking analysis was conducted via vendor independent software, Tomtec. After intervention, LV function significantly improved (from -12.8±3.9 to -16.7±1.7; p<0.001), however normal values were not reached even at medium term follow-up (-18.3±1.7 vs. -20±1.6; p=0.002). Medium term longitudinal strain correlated with pre intervention EF (r=0.58, p=0.006). Moreover, medium term subnormal values were more frequently associated with bicuspid aortic valve (33.3% vs. 66.6%; p<0.05). CONCLUSION: LV myocardial function in neonates with CoA can be feasibly evaluated and followed up by speckle tracking echocardiography. LV subendocardial dysfunction however, remains in early infancy coarctation long after repair. Long-term follow-up through adulthood using myocardial deformation measurements should shed light on the natural history and consequences of this anomaly.

Late Diagnosis of Coarctation Despite Prenatal Ultrasound and Postnatal Pulse Oximetry.

OBJECTIVES: To determine what contribution prenatal ultrasound screening and neonatal pulse oximetry screening (POS) make to the timely diagnosis of neonatal coarctation of the aorta (CoA). METHODS: We identified infants and fetuses diagnosed with isolated CoA in our referral area between 2003 and 2012 who died without surgery, underwent surgical repair before 2 months of age, or were terminated after a prenatal diagnosis. Clinical data were collected from hospital charts. RESULTS: Only 3 of the 90 cases were diagnosed prenatally. Two of the 3 were born alive and in 1 case the couple opted for termination of pregnancy. Nineteen of the remaining 87 cases were born in units that used POS (hand and foot) and 4 of 19 screened positive. Of the remaining 83 cases, 46 were discharged undiagnosed (7 after nondiagnostic echocardiography), including 9 with a murmur and weak femoral pulses and 8 with a murmur and normal pulses. One was diagnosed postmortem after dying at home, and 22 of the remaining 45 discharged infants were in circulatory failure on readmission. Five of the patients who were not discharged died without surgery and undiagnosed CoA was the most probable cause of death in 2 of these patients. CONCLUSIONS: The contribution of prenatal ultrasound screening and postnatal POS to the timely diagnosis of CoA was low. Careful physical examination of all newborns therefore continues to play a fundamental role in detecting this life-threatening cardiac defect, and better screening methods need to be developed.

Pulse oximetry screening and prenatal diagnosis play complementary roles in reducing risks in simple transposition of the great arteries.

AIM: This study quantified the contribution of pulse oximetry screening to an early diagnosis of simple transposition. We also estimated the proportion of neonates with this life-threatening cardiac defect who could benefit from prenatal diagnosis, even when pulse oximetry screening had been implemented. METHODS: This population-based, retrospective, cohort study of cases born from 2003 to 2013 used data from surgical files, the Swedish Causes of Death Registry and the National Forensic Medicine database. The main outcome measures were early postnatal circulatory instability, pre-operative death, neurological morbidity and risk of discharge before diagnosis. RESULTS: We identified 89 cases, including three diagnosed prenatally. Hospitals using pulse oximetry screening diagnosed all 31 neonates before discharge, including seven as a result of screening, but 10 of 55 infants in the nonscreening hospitals were discharged undiagnosed (p = 0.017). Prenatal diagnosis could have decreased the risk of early circulatory instability, pre-operative death or neurological morbidity in 12 of the 72 infants born in referring hospitals (17%). There was one pre-operative death and no postoperative deaths at a mean follow-up of 4.7 years. CONCLUSION: Pulse oximetry screening minimised the risk of discharging infants with transposition, but prenatal diagnosis would have been necessary to avoid early circulatory instability in 17% of cases.