Ultrasound may be doing a better job overall of diagnosing critical congenital heart disease (CHD) prenatally, but that's not necessarily the case in poorer and more rural communities, according to research presented on Monday at the Pediatric Academic Societies (PAS) annual meeting in San Diego.
A team of researchers from the Children's Hospital of Wisconsin found that critical CHD was more likely to be missed on prenatal ultrasound in patients from those vulnerable communities than in those from more affluent and urban areas.
"There are health disparities in the detection of critical congenital heart disease," presenter Dr. Garick Hill said.
The need for early diagnosis
It's important to diagnose critical congenital heart disease prenatally because it enables babies to be delivered at a specialized center with reduced rates of preoperative morbidity and mortality, according to Hill and colleagues. As a pediatric cardiologist who specializes in fetal echocardiography, Hill said he gets to see firsthand the difference it makes when critical CHD is diagnosed before birth.
"I therefore have a great interest in improving the prenatal detection rate," he told AuntMinnie.com.
To calculate the prenatal detection rate for congenital heart disease and to determine the risk factors for a missed prenatal diagnosis, the group performed a chart review of 535 subjects with critical CHD. All had surgical or catheter intervention at the institution between 2007 and 2013 in the first 30 days of life. The researchers also examined the type of ultrasound view (i.e., four-chamber view, outflow tract view, or other) required to make the diagnosis.
Hill and colleagues compared the subjects with a prenatal diagnosis to those without a diagnosis, analyzing the data to identify any factors associated with a missed diagnosis.
Of the 535 subjects, 326 (61%) had received a prenatal diagnosis of critical CHD. The researchers noticed an improvement in detection performance over the study period, climbing from 44% in 2007 to 69% in 2013. The diagnosis rates varied according to the specific type of CHD.
| CHD diagnosis by disease type | |||
| Disease type | No. of cases | Prenatal diagnosis | Postnatal diagnosis |
| Tricuspid atresia | 14 | 100% | 0% |
| Double inlet left ventricle | 19 | 94.7% | 5.3% |
| Atrioventricular septal defect | 14 | 85.7% | 14.3% |
| Ebstein's anomaly | 7 | 85.7% | 14.3% |
| Single ventricle | 19 | 84.2% | 15.8% |
| Hypoplastic left heart syndrome | 95 | 82.1% | 17.9% |
| Pulmonary atresia | 14 | 78.6% | 21.4% |
| Pulmonary atresia with intact ventricular septum | 16 | 75% | 25% |
| Double outlet right ventricle | 41 | 73.2% | 26.8% |
| Truncus arteriosus | 28 | 67.9% | 32.1% |
| Interrupted aortic arch | 21 | 61.9% | 38.1% |
| Tetralogy of Fallot | 22 | 59.1% | 40.9% |
| Transposition of the great arteries | 83 | 43.4% | 56.6% |
| Aortic stenosis | 12 | 41.7% | 58.3% |
| Coarctation of the aorta | 98 | 37.8% | 62.2% |
| Pulmonary stenosis | 8 | 37.5% | 62.5% |
| Total anomalous pulmonary venous return | 15 | 6.7% | 93.3% |
Four independent factors were associated with a missed prenatal diagnosis:
- A lesion that required a four-chamber view to make the diagnosis (p < 0.0001)
- Absence of another organ system anomaly (p < 0.0001)
- Living in a higher poverty area (p = 0.02)
- Living in a more rural ZIP code (p = 0.002)
The researchers believe the differences in prenatal detection are due to training issues in rural, impoverished communities.
"While the equipment has improved over time, I don't believe it could account for the difference in diagnostic rates," Hill told AuntMinnie.com. "The difference between communities is most noticeable as the complexity of the view required increases, but I don't believe this is related to equipment."
As a result, interventions to improve the prenatal detection rate of critical CHD should focus on impoverished, rural communities, according to the researchers.
The group's goal is to develop a mobile training program that can travel to rural medical offices to provide training and education, Hill said.
"We would also like to set up a system where questionable or concerning images could be transmitted and reviewed immediately by pediatric cardiologists," he said.
