Feasibility of low radiation dose retrospectively-gated cardiac CT for functional analysis in adult congenital heart disease.

BACKGROUND: The use of cardiac computed tomography (CT) in the evaluation of adult congenital heart disease patients is limited due to concerns of high radiation doses. The purpose of this study was to prospectively assess whether low radiation dose cardiac CT is feasible to evaluate ventricular systolic function in adults with congenital heart disease. METHODS: The study group included 30 consecutive patients with significant congenital heart disease who underwent a total of 35 ECG-gated cardiac CT scans utilizing a 320-detector row CT scanner. Each study included a non-contrast scan and subsequent contrast-enhanced retrospectively-gated acquisition. Effective radiation dose was estimated by multiplying the dose length product by a k-factor of 0.014mSv/mGycm. RESULTS: The mean age of the patients was 34.4±8.9years, 60% were men, and mean body mass index was 24.2±4.3kg/m2. A majority of patients (n=28, 93.3%) had contraindications to cardiac MRI. A tube potential of 80kV was used in 27 (77.1%) of the contrast-enhanced scans. The mean signal-to-noise and contrast-to-noise ratios were 11.5±3.9 and 10.3±3.7, respectively. The median radiation dose for non-contrast and contrast-enhanced images were 0.1mSv (0.07-0.2mSv) and 0.94mSv (0.5-2.1mSv), respectively. All 35 CT scans were successfully analyzed for ventricular systolic function. CONCLUSIONS: A low radiation contrast-enhanced, retrospectively-gated cardiac CT with a median radiation dose of less than 1mSv was successful in evaluating ventricular systolic function in 30 consecutive adult congenital heart disease patients who underwent a total of 35 scans.

Emerging Research Directions in Adult Congenital Heart Disease: A Report From an NHLBI/ACHA Working Group.

Congenital heart disease (CHD) is the most common birth defect, affecting about 0.8% of live births. Advances in recent decades have allowed >85% of children with CHD to survive to adulthood, creating a growing population of adults with CHD. Little information exists regarding survival, demographics, late outcomes, and comorbidities in this emerging group, and multiple barriers impede research in adult CHD. The National Heart, Lung, and Blood Institute and the Adult Congenital Heart Association convened a multidisciplinary working group to identify high-impact research questions in adult CHD. This report summarizes the meeting discussions in the broad areas of CHD-related heart failure, vascular disease, and multisystem complications. High-priority subtopics identified included heart failure in tetralogy of Fallot, mechanical circulatory support/transplantation, sudden cardiac death, vascular outcomes in coarctation of the aorta, late outcomes in single-ventricle disease, cognitive and psychiatric issues, and pregnancy.

Overweight predicts poorer exercise capacity in congenital heart disease patients.

BACKGROUND: Overweight (OW) and obesity (OB) are endemic in the United States and affect adolescents and adults with congenital heart disease (ACHD). Defining the burden of excess weight on the cardiovascular system in ACHD is the goal of this study. Limitation of exercise capacity due to overweight or obesity might be reversible with weight loss and improve quality of life for ACHD adults. METHODS: Exercise tests performed using a Bruce protocol and measurement of maximum oxygen consumption were retrospectively reviewed on 418 CHD patients. OW and OB were defined as the 85-95 or > 95 percentile respectively for age and gender or by adult criteria. Severity of CHD was assigned based on criteria published in standard guidelines. RESULTS: 63 patients had mild, 198 moderate, and 157 severe heart disease. Each ACHD group was 32 to 34% OW or OB. Measured exercise time (ET) of CHD patients with moderate or severe heart disease was less than that of controls in each weight categories. However, OB or OW people have shorter ET than their normal weight peers with CHD. Multiple regression using ET as the dependent variable finds that female sex, relative BMI, and VE/VCO2 at peak exercise are all associated with lesser ET with high significance. Peak heart rate is associated with greater ET, with borderline significance. Severity of heart disease is not independently associated with ET. CONCLUSIONS: OW and OB are strongly associated with reduced ET in persons with congenital heart disease. Losing weight may improve exercise capacity in ACHD.

Relationship of birth weight with congenital cardiovascular malformations in a population-based study.

INTRODUCTION: A known comorbidity of congenital cardiovascular malformations is low birth weight, but the reasons for this association remain obscure. This retrospective study examines the relationship between congenital cardiovascular malformations and the birth weight of singletons, taking into account differences in gestational age and other factors. METHODS: Using data from the retrospective, population-based Baltimore-Washington Infant Study, six types of congenital cardiovascular malformations were investigated in comparison with controls (n=3519) through linear regression: d-transposition of the great arteries (n=187), other conotruncal heart defects (n=361), endocardial cushion defects (n=281), left heart obstructive lesions (n=507), atrial septal defects (n=281), and membranous ventricular septal defects (n=622). RESULTS: Infants with conotruncal heart defects (-218 g), endocardial cushion defects with Down syndrome (-265 g), endocardial cushion defects without Down syndrome (-194 g), left heart obstructive lesions (-143 g), atrial septal defects (-150 g), and membranous ventricular septal defects (-127 g) showed significant birth weight deficits, adjusting for gestational age, and other covariates. Infants with d-transposition of the great arteries (-67 g) did not show significant birth weight deficits compared with the control group. DISCUSSION: The degree of birth weight decrement appears to be highly related to the specific type of congenital cardiovascular malformation. As a whole, these infants do not exhibit low birth weights solely because of being premature, and thus other mechanisms must underlie these associations.

Increased postoperative respiratory complications in heterotaxy congenital heart disease patients with respiratory ciliary dysfunction.

OBJECTIVE(S): Congenital heart disease (CHD) and heterotaxy patients have increased postoperative and respiratory complications. We recently showed CHD-heterotaxy patients can have respiratory ciliary dysfunction (CD) similar to that associated with primary ciliary dyskinesia, including low nasal nitric oxide and abnormal ciliary motion. In this study, we investigated whether CHD-heterotaxy patients with CD may have worse postsurgical outcomes. METHODS: We examined postsurgical outcome in 13 heterotaxy-CHD patients with CD (25 surgeries), compared with 14 heterotaxy-CHD patients without CD (27 surgeries). Outcome data were collected for each surgery, including respiratory complications, tracheostomy, use of inhaled ß-agonists or nitric oxide, length of hospital stay, days on ventilator, and death. RESULTS: The CD versus the no-CD CHD cohorts had similar Risk Adjustment in Congenital Heart Surgery-1 risk categories, repair track, age at surgery, and follow-up evaluation times. Respiratory complications (76% vs 37%; P = .006), need for tracheostomy (16% vs 0%; P = .047), and use of inhaled ß-agonists (64% vs 11%; P = .0001) all were increased significantly in heterotaxy-CHD patients with CD. No significant differences were detected in postoperative hospital stay, days on mechanical ventilation, or surgical mortality. A trend toward increased mortality for the CD group beyond the postoperative period was observed (33% vs 0%; P = .055) in patients younger than age 10 years. CONCLUSIONS: Our findings showed that heterotaxy-CHD patients with CD may have increased risks for respiratory deficiencies. Overall, there was a trend toward increased mortality in CD patients with intermediate follow-up evaluation. Because ß-agonists are known to increase ciliary beat frequency, presurgical screening for CD and perioperative treatment of CD patients with inhaled ß-agonists may improve postoperative outcomes and survival.

Improving heart disease knowledge and research participation in adults with congenital heart disease (the Health, Education and Access Research Trial: HEART-ACHD).

OBJECTIVE: The objective of this prospective multi-center study was to evaluate heart disease knowledge within the adult congenital heart disease (ACHD) population, pilot an educational intervention and assess interest in research participation among new patients at ACHD clinics. BACKGROUND: Many adults with congenital heart disease lack knowledge about their heart condition that may contribute to undesirable outcomes. METHODS: Patients ≥18 years of age were recruited upon their first presentation to an ACHD clinic and underwent an educational intervention consisting of creation of a personal health information 'passport' and an introduction to web-based resources. Subjects were asked to complete initial and follow-up surveys documenting their perceived knowledge. RESULTS: Nine hundred twenty-two subjects were recruited from 12 ACHD centers, and 520 (57%) completed follow-up surveys. Patients who completed the follow-up survey were more likely to be women, have more education, and have mild heart disease. At follow-up, the ability of the subjects to name their heart condition improved (78% to 83%, p=0.002). Improvements were seen in mean Likert items regarding perceived knowledge of appropriate exercise (p<0.0001), symptoms of heart rhythm problems or endocarditis (p<0.0001), reasons for cardiac tests (p<0.007), and birth control options and pregnancy safety (p<0.0001). On follow-up, subjects reported a better understanding of medical research (p<0.01), and higher interest in research participation (p<0.003). CONCLUSION: This joint clinician-patient pilot program will help inform future efforts toward patient education and participation in research with a focus on standardization of protocols for life-long longitudinal follow-up and continued multi-center collaboration in the ACHD population.

Prevalence and predictors of gaps in care among adult congenital heart disease patients: HEART-ACHD (The Health, Education, and Access Research Trial).

OBJECTIVES: The goal of this project was to quantify the prevalence of gaps in cardiology care, identify predictors of gaps, and assess barriers to care among adult congenital heart disease (adult CHD) patients. BACKGROUND: Adult CHD patients risk interruptions in care that are associated with undesired outcomes. METHODS: Patients (18 years of age and older) with their first presentation to an adult CHD clinic completed a survey regarding gaps in, and barriers to, care. RESULTS: Among 12 adult CHD centers, 922 subjects (54% female) were recruited. A >3-year gap in cardiology care was identified in 42%, with 8% having gaps longer than a decade. Mean age at the first gap was 19.9 years. The majority of respondents had more than high school education and knew their heart condition. The most common reasons for gaps included feeling well, being unaware that follow-up was required, and complete absence from medical care. Disease complexity was predictive of a gap in care with 59% of mild, 42% of moderate, and 26% of severe disease subjects reporting gaps (p < 0.0001). Clinic location significantly predicted gaps (p < 0.0001), whereas sex, race, and education level did not. Common reasons for returning to care were new symptoms, referral from provider, and desire to prevent problems. CONCLUSIONS: Adult CHD patients have gaps in cardiology care; the first lapse commonly occurred at age ∼19 years, a time when transition to adult services is contemplated. Gaps were more common among subjects with mild and moderate diagnoses and at particular locations. These results provide a framework for developing strategies to decrease gaps and address barriers to care in the adult CHD population.

High prevalence of respiratory ciliary dysfunction in congenital heart disease patients with heterotaxy.

BACKGROUND: Patients with congenital heart disease (CHD) and heterotaxy show high postsurgical morbidity/mortality, with some developing respiratory complications. Although this finding is often attributed to the CHD, airway clearance and left-right patterning both require motile cilia function. Thus, airway ciliary dysfunction (CD) similar to that of primary ciliary dyskinesia (PCD) may contribute to increased respiratory complications in heterotaxy patients. METHODS AND RESULTS: We assessed 43 CHD patients with heterotaxy for airway CD. Videomicrocopy was used to examine ciliary motion in nasal tissue, and nasal nitric oxide (nNO) was measured; nNO level is typically low with PCD. Eighteen patients exhibited CD characterized by abnormal ciliary motion and nNO levels below or near the PCD cutoff values. Patients with CD aged >6 years show increased respiratory symptoms similar to those seen in PCD. Sequencing of all 14 known PCD genes in 13 heterotaxy patients with CD, 12 without CD, 10 PCD disease controls, and 13 healthy controls yielded 0.769, 0.417, 1.0, and 0.077 novel variants per patient, respectively. One heterotaxy patient with CD had the PCD causing DNAI1 founder mutation. Another with hyperkinetic ciliary beat had 2 mutations in DNAH11, the only PCD gene known to cause hyperkinetic beat. Among PCD patients, 2 had known PCD causing CCDC39 and CCDC40 mutations. CONCLUSIONS: Our studies show that CHD patients with heterotaxy have substantial risk for CD and increased respiratory disease. Heterotaxy patients with CD were enriched for mutations in PCD genes. Future studies are needed to assess the potential benefit of prescreening and prophylactically treating heterotaxy patients for CD.

Hypoplastic left heart syndrome and other left heart disease: evolution of understanding from population-based analysis to molecular biology and back again--a brief overview.

Congenital cardiac disease is the most common birth defect, occurring in approximately 1 in 1000 live births. Congenital cardiac defects have associations, whether with gender, race, or specific chromosomal abnormalities, potentially allowing grouping of defects to be studied in an effort to develop an understanding of aetiological factors. The Baltimore-Washington Infant Study provides full ascertainment of a population of infants with congenital cardiac disease born in a defined geographic region. The fundamental hypotheses generated at the inception of the Baltimore-Washington Infant Study included the central idea that the outcome of birth, including the development of congenital cardiac malformations, was influenced by environmental factors and their route of introduction into a genetically susceptible host. Evidence exists that supports the concept that both genetic and environmental factors contribute to the development of diseases of the left heart.

Liver disease after the Fontan procedure: what the hepatologist needs to know.

Fifty years ago, only a quarter of infants born with congenital heart disease (CHD) survived beyond the first year of life. It has been estimated that 80% to 85% of patients can expect to reach adulthood. Today, there are close to 1 million adults living with CHD in the United States alone. Since its introduction, the Fontan operation has become established as the dominant surgical repair in patients with univentricular heart physiology. Long-term morbidity associated with this procedure is being more commonly appreciated and liver complications have become more frequently apparent. Hepatologist awareness and familiarity in managing this population alongside the CHD specialist is important for the care of these patients. This dual perspective can provide comprehensive integrated care.

Association of congenital cardiovascular malformations with 33 single nucleotide polymorphisms of selected cardiovascular disease-related genes.

INTRODUCTION: Clark (1996) proposed that abnormal blood flow is related to some congenital cardiovascular malformations (CCVMs), particularly CCVM with obstruction to blood flow. Our hypothesis is that CCVMs may relate to genes that affect blood coagulation or flow. We studied whether polymorphisms of such genes are related to CCVMs; previous association of these SNPs to conotruncal CCVMs is described. METHODS: We assessed risk of pulmonary stenosis (PS, N = 120), atrial septal defect (ASD, N = 108), aortic stenosis (AS, N = 36), and coarctation of the aorta (CoAo, N = 64), associated with 33 candidate genes, selected for their relationship to blood flow affected by homocysteine metabolism, coagulation, cell-cell interaction, inflammation, or blood pressure regulation. RESULTS: Effects were specific to cardiac phenotype and race. CoAo was associated with MTHFR (-667) C>T (odds ratio [OR] for TT 3.5, 95% confidence limits [CI] 1.4-8.6). AS was associated with a polymorphism of SERPINE1, G5>G4, OR = 5.6 for the homozygote with 95% CI 1.4-22.9. Unique polymorphisms were associated with increased risk of ASD and PS: NPPA 664G>A with ASD (OR of 2.4, 95%CI 1.3-4.4) and NOS3 (-690) C>T with PS (OR 6.1; 95% CI 1.6-22.6 in the African American population only). For ASD, the NPPA (-664) G>A SNP there was increased risk from the variant genotype only in maternal smokers (OR 2.6; 95% CI 1.0-7.2). CONCLUSIONS: Genes affecting vascular function and coagulation appear to be promising candidates for the etiology of cardiac malformations and warrant further study.

Multiple papillary fibroelastomas of the heart.

We report the case of a 41-year-old woman who presented with extensive papillary fibroelastomas of the heart after multiple previous surgical procedures for hypertrophic cardiomyopathy. This case is significant because of the locally aggressive nature of the cardiac papillary fibroelastoma.

Ezetimibe treatment of pediatric patients with hypercholesterolemia.

OBJECTIVE: To review the efficacy of ezetimibe monotherapy for treatment of hypercholesterolemia in pediatric patients. STUDY DESIGN: This is a retrospective review of all pediatric patients who received ezetimibe monotherapy as treatment for hypercholesterolemia and for whom follow-up clinical and lipid results were available. Of 36 identified patients, 26 had lipoprotein profiles suggestive of familial hypercholesterolemia (FH), and 10 had profiles suggestive of familial combined hyperlipidemia (FCHL). RESULTS: After a mean 105 days of treatment with ezetimibe (range, 32-175 days), total cholesterol (TC) levels decreased from 7.3 +/- 1.0 mmol/L to 5.7 +/- 1.0 mmol/L (P < .0001), and low-density lipoprotein cholesterol (LDL-C) levels decreased from 5.3 +/- 0.9 mmol/L to 3.9 +/- 0.8 (P < .0001) in patients with FH. In patients with FCHL, TC levels decreased from 6.4 +/- 2.0 mmol/L to 5.6 +/- 0.4 mmol/L (P < or = .002), and LDL-C levels decreased from 4.7 +/- 1.0 mmol/L to 3.8 +/- 0.6 mmol/L (P < or = .005). For all patients, the mean decrease in individual LDL-C values was 1.5 +/- 0.9 mmol/L or 28%. There was no significant change in triglyceride or high-density lipoprotein cholesterol levels with ezetimibe. Patients were maintained on ezetimibe with no adverse effects attributable to the medication for as long as 3.5 years. At a mean of 13.6 months (range, 1-44 months) after the initiation of ezetimibe, LDL-C levels remained decreased at 4.0 +/- 0.6 mmol/L. CONCLUSIONS: In this small retrospective series of children and adolescents with hypercholesterolemia, ezetimibe was safe and effective in lowering LDL-C levels.

Severe tricuspid valve stenosis secondary to pacemaker leads presenting as ascites and liver dysfunction: a complex problem requiring a multidisciplinary therapeutic approach.

Tricuspid stenosis secondary to ventricular pacemaker leads is uncommon. We present a unique case of iatrogenic tricuspid stenosis secondary to fusion of the valve leaflets to transvenous implanted pacing leads. This occurred in an adult with childhood repaired Tetralogy of Fallot and high grade surgical heart block following multiple pacemaker procedures. The case was complicated by superior vena cava (SVC) and innominate vein stenosis secondary to implanted pacing leads, severe tricuspid valve (TV) stenosis, perforation of the heart by one of the implanted transvenous ventricular pacing leads, prolapse of the transvenous atrial pacing lead into the right ventricle, and unusual coronary sinus anatomy. We describe a multidisciplinary approach to management.

Transition to adulthood in congenital heart disease: missed adolescent milestones.

PURPOSE: To determine whether adults with congenital heart disease (CHD) are better adjusted than adults with acquired heart disease (AHD). METHODS: Twenty-five adults with CHD completed the Patient Adjustment to Illness Self Report (PAIS-SR). RESULTS: CHD patients had good adjustment for Heath Care Orientation and Family Relations, but poorer adjustment for Vocational, Social and Domestic Environment, Sexual Relations, and Psychological Distress. CONCLUSIONS: The needs of CHD patients are not being met.

Report of the National Heart, Lung, and Blood Institute Working Group on research in adult congenital heart disease.

The Working Group on research in adult congenital heart disease (ACHD) was convened in September 2004 under the sponsorship of National Heart, Lung, and Blood Institute (NHLBI) and the Office of Rare Diseases, National Institutes of Health, Department of Health and Human Services, to make recommendations on research needs. The purpose of the Working Group was to advise the NHLBI on the current state of the science in ACHD and barriers to optimal clinical care, and to make specific recommendations for overcoming those barriers. The members of the Working Group were chosen to provide expert input on a broad range of research issues from both scientific and lay perspectives. The Working Group reviewed data on the epidemiology of ACHD, long-term outcomes of complex cardiovascular malformations, issues in assessing morphology and function with current imaging techniques, surgical and catheter-based interventions, management of related conditions including pregnancy and arrhythmias, quality of life, and informatics. After research and training barriers were discussed, the Working Group recommended outreach and educational programs for adults with congenital heart disease, a network of specialized adult congenital heart disease regional centers, technology development to support advances in imaging and modeling of abnormal structure and function, and a consensus on appropriate training for physicians to provide care for adults with congenital heart disease.

Genetic and environmental influences on malformations of the cardiac outflow tract.

Congenital cardiovascular malformations are the most common form of birth defect recorded. Specific malformations of the outflow portions of the heart are termed conotruncal malformations and arise from the septation of the common conotruncus of the heart. There are multiple lines of evidence that point towards genetic-environmental interactions in the genesis of conotruncal congenital cardiovascular malformations. In particular, environmental exposures that involve vitamin A, retinol, folic acid or retinol receptors are identified as cardiac teratogens. Other environmental agents for which there is evidence of cardiac teratogenicity for outflow tract malformations include nitrofen, ambient air pollution, chlorinated hydrocarbons and pesticides. Genetic polymorphisms of xenobiotic metabolism are clearly differentiating in the effect of potential teratogens. Work in this field is at a new cusp, with the ability to measure xenobiotic exposure, document xenobiotic metabolizing genetic polymorphisms and integrate these data into models of cardiac teratogenesis.

Transcutaneous implantation of an internal cardioverter defibrillator in a small infant with recurrent myocardial ischemia and cardiac arrest simulating sudden infant death syndrome.

This report describes the implantation of a transcutaneous ICD system using a small patch electrode in the subscapular position, and an active-can device in a 5.3-kg infant. The indication for ICD implantation was recurrent cardiac arrest in the presence of normal coronary anatomy. Metabolic evaluation suggested a defect in fatty acid oxidation.

Population-based study of l-transposition of the great arteries: possible associations with environmental factors.

BACKGROUND: L-transposition of the great arteries (l-tga) is an uncommon congenital cardiovascular malformation that occurs from abnormal looping of the primitive cardiac tube. Little is known about risk factors for the development of l-tga. METHODS: This study is a case-control study of 36 cases of l-tga compared to 3,495 population-based live born infant controls in the Baltimore Washington Infant Study (1981-1989 births). Extensive personal and occupational exposure data from parental interviews were available for all subjects. A geographic information system was used to identify potential environmental exposures, for example, hazardous waste sites prioritized for cleanup (National Priority List sites). Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using exact parameter estimates from logistic regression. RESULTS: Most infants with l-tga had multiple cardiovascular anomalies, with single ventricle in 47%. Over 75% of all cases of l-tga occur in two regions of contiguous cases. Within these regions, the case control OR of l-tga are 13.4 (95% CI, 4.7-37.8) Both areas are characterized by release of toxic chemicals into air and by hazardous waste sites. Parental exposures to hair dye, smoking and laboratory chemicals are also associated with case status. CONCLUSIONS: L-tga, a congenital cardiovascular malformation due to very early abnormalities in embryogenesis, is associated strongly with residency in two small regions of Maryland and District of Columbia (DC), and with other parental personal or occupational exposures. Additional research is needed to identify the components of spatial and other associations that constitute etiologic risk factors.