March 29, 2012 — Physician-researchers from the Cardiac Center at The Children’s Hospital of Philadelphia presented new findings on pediatric cardiovascular disease this week at the American College of Cardiology’s 61st Annual Scientific Sessions in Chicago.
During abstract presentations they described: stress and depression in women carrying a baby with congenital heart disease (CHD), research showing that acute occlusive artery injury is common in young children after a cardiac catheterization and discussions of graft survival in donor hearts with depressed ventricular function.
Children’s Hospital clinicians also participated in and moderated a cardiac catheterization procedure that was broadcasted live to the conference from CHOP facilities in Philadelphia. CHOP clinicians also served as moderators during several sessions, participated on expert panels, and shared experiences regarding the treatment of adult patients living with hypoplastic left heart syndrome (HLHS).
Examples of the research presented at abstract sessions
Stress, Depression, Anxiety Common among Women after Prenatal Diagnosis of Heart Defects in Fetus
A prenatal diagnosis of congenital heart disease (CHD) offers beneficial opportunities for parents to learn, plan and prepare, but may entail significant psychological stress, which may have health consequences for both parents and children. This study, from the Fetal Heart Program and the Center for Family Interventional Science at CHOP, characterized the type and degree of stress among mothers who have a fetus diagnosed with CHD.
The researchers used a self-report questionnaire to assess 59 mothers at follow-up visits two to four weeks after the mothers received a diagnosis of serious CHD. Maternal psychological stress was significant, with 39 percent of the subjects exhibiting scores consistent with post-traumatic stress disorder, 22 percent with depression, and 31percent with state anxiety.
Healthy partner relationships and positive coping mechanisms may buffer parents from such stress, while lower income was associated with higher depression. After controlling for marital satisfaction and income, the coping variable “denial” was most associated with increased traumatic stress, anxiety and depression. The study suggests that clinicians may improve outcomes by creating stress reduction strategies for mothers, with a focus on denial as a coping variable during recurrent sustained prenatal counseling sessions.
- Jack Rychik et al, Maternal Psychological Stress after Prenatal Diagnosis of Congenital Heart Disease
Acute Occlusive Arterial Injury is Common in Young Children after Pediatric Cardiac Catheterization
Acute occlusive arterial injury is a known complication after pediatric cardiac catheterization, with estimated prevalence ranging from 0.6 percent to 9.6 percent, based on older studies with small sample sizes. This research aimed to determine prevalence of acute arterial injury at a single center and to identify risk factors.
The study team performed a retrospective review of all cardiac catheterization procedures performed at The Children’s Hospital of Philadelphia between January 2005 and June 2010. A total of 3,254 patients had 5,715 catheterization procedures, of which 3,859 used femoral arterial cannulation. The baseline prevalence of acute occlusive arterial injury was 4.3 percent among procedures with arterial access.
In 721 patients younger than 6 months, the prevalence was 18 percent. In the 118 patients younger than 6 months with an arterial catheter larger than size 4French, the prevalence was 36 percent. Occlusive arterial injury was independently associated with younger patient age, higher contrast volume, larger arterial access catheter, number of arterial exchanges, and lower ending blood clotting time.
Acute occlusive arterial injury is most likely to occur in younger children requiring larger arterial access points. While arterial cannulation is often unavoidable, say the researchers, clinicians should use the smallest catheter size possible and minimize catheter exchanges. Clinicians may potentially reduce the risk of acute occlusive arterial injury by using antegrade access to the left heart when the anatomy permits it, by using alternative imaging modalities to limit the need for contrast, and by emphasizing attention to consistent therapeutic anticoagulation. The study is an important benchmark for future studies aimed at decreasing risk and determining longer-term consequences.
- Andrew C. Glatz et al, Prevalence and Risk Factors for Acute Occlusive Arterial Injury Following Pediatric Cardiac Catheterization in the Modern Era at a Large Volume Center
Donor Hearts with Depressed Ventricular Function Have Similar Graft Survival to Hearts with Normal Function
Mortality for children on the waiting list for pediatric heart transplantation remains high, but potential donor hearts with depressed ventricular function are often declined. This CHOP study assessed whether graft survival differs in children receiving donor hearts with depressed left ventricular ejection fraction (LVEF) compared to donor hearts with normal LVEF.
The study team performed a retrospective review of 3,306 pediatric heart transplants from the United Network of Organ Sharing Database from October 1999 to June 2011. Of that total, LVEF was mildly depressed in 245 patients (7 percent) and moderately to severely depressed in 172 patients (5 percent).
The researchers reviewed graft survival at 30 days, 6 months, 1 year and 5 years after transplant. They found that median graft survival from donors with normal LVEF (10.6 years) was statistically similar to survival from donors with mildly depressed LVEF (9.7 years) and from donors with moderately to severely depressed LVEF (9.1 years). The similar survival rates persisted after multivariable analysis.
Although use of donors with depressed LVEF in pediatric heart transplants is uncommon, graft survival is not significantly different compared to donor hearts with normal LVEF. Thus donor hearts with depressed ventricular function should be considered in selected pediatric heart transplant patients.
- Joseph W. Rossano et al, Pediatric Heart Transplantation from Donors with Depressed Ventricular Function: An Analysis of the United Network of Organ Sharing Database
Atrioventricular Valve Regurgitation in Fetuses with Atrioventricular Canal Defects does not Progress During Mid- to Late Pregnancy for Most Babies
Atrioventricular valve regurgitation (AVVR) influences morbidity and mortality in patients with atrioventricular canal defect (AVC). Fetal cardiac structures are subject to hemodynamic changes as well as growth and maturation during gestation, which may alter the degree of AVVR and affect prognosis.
Researchers from the Cardiac Center at The Children’s Hospital of Philadelphia at the American College of Cardiology Scientific Session today present research that shows that AVVR does not progress in the second and third trimester of pregnancy for most fetuses with AVC. This could have significant implications for counseling, follow-up and delivery plans for babies with AV Canal defects.
The study team analyzed 43 fetuses with AVC seen in the Fetal Heart Program between January 2008 and September 2010. The degree of AVVR was assessed by color Doppler imaging and categorized by grade (grade 0 no AVVR, grade 1 hemodynamically insignificant AVVR, grade 2 hemodynamically important AVVR). The researchers found that 60 percent had no change, 14 percent had a decrease and 26 percent had an increase in the AVVR grade. Two fetuses progressed from Grade 0 or 1 to Grade 2, which was considered a significant hemodynamic change. The researchers say that transitional/incomplete AV canal defects may be more susceptible to AVVR progression.
- Brooke T. Davey et al, The Natural History of Atrioventricular Valve Regurgitation Throughout Fetal Life in Patients with Atrioventricular Canal Defects
Extra Oxygen or Carbon Dioxide Has Minimal Effect on Systemic to Pulmonary Collateral Flow In Single Ventricle Patients With Cavopulmonary Connections
Systemic to pulmonary collateral flow (SPCF) is a significant hemodynamic burden in patients with superior and total cavopulmonary connections. Hypercarbia (too much carbon dioxide) and hyperoxia (excess oxygen), which can frequently occur during anesthesia and ICU care, are known to alter pulmonary and systemic vascular resistance.
This study from The Children’s Hospital of Philadelphia quantified the effect of hypercarbia and hyperoxia on SPCF, using phase-contrast MRI. The researchers measured SPCF as the difference in aortic and caval flow in intubated patients breathing room air. They remeasured SPCF under conditions of hyperoxia in 7 patients with superior and total cavopulmonary connections, and under hypercarbia in 14 separate patients with superior and cavopulmonary connections.
Hyperoxia resulted in a slight increase in SPCF representing an additional 5 percent of aortic flow, while hypercarbia did not significantly affect SPCF. This suggests that SPCF is minimally affected by hyperoxia and hypercarbia in patients with cavopulmonary physiology.
- Kevin K. Whitehead, et. al, Effect of Hyperoxia and Hypercarbia on Systemic to Pulmonary Collateral Flow in Patients with Cavopulmonary Connections
Measurement of Regurgitant Volume by Phase Contrast MRI May Be Useful in Evaluation of Aortic Insufficiency
Phase contrast magnetic resonance imaging (PC-MRI) has proven very reliable in quantification of aortic insufficiency in patients with various forms of aortic valve disease, but anecdotal data suggest that the regurgitant fraction (RF) may occasionally be significantly underestimated.
This CHOP study compared 3 methods of calculating RF. The study team reviewed MRI records from 2009 to present for patients with RF of 5 percent or greater or mild aortic insufficiency by echocardiography. They also reviewed MRIs for aortic insufficiency RF calculated by at least 2 methods: reverse flow divided by forward flow at the valve sinuses or subtubular junction (RF-sinus and RF-STJ) and the difference in forward flow at the sinuses and total vena caval flow, all divided by forward flow at the sinuses (RF-caval).
Aortic RF quantified by PC-MRI is very consistent between measurement locations in patients with any degree of aortic insufficiency. However, there may be rare cases when direct measurement may underestimate RF because of chaotic flow in the ascending aorta during diastole. Indirect measurement of the regurgitant volume by subtracting caval flow from aortic forward flow may provide a useful adjunct to routine evaluation of aortic insufficiency to avoid cases of significant underestimation.
- Kevin K. Whitehead, et al, Comparison of Direct and Indirect Measurements of Aortic Valve Regurgitation Using Phase Contrast Magnetic Resonance Velocity Mapping
Joey McCool Ryan, Children's Hospital of Philadelphia, 267-426-6070 or firstname.lastname@example.org