Long-Term outcomes in adult patients with congenital heart disease considered for transplantation: A single center study

BACKGROUND

Adult congenital heart disease (ACHD) patients pose unique challenges in identifying the time for transplantation and factors influencing outcomes.

OBJECTIVE

To identify hemodynamic, functional, and laboratory parameters that correlate with 1- and 10-year outcomes in ACHD patients considered for transplantation.

METHODS

A retrospective chart review of long-term outcomes in adult patients with congenital heart disease (CHD) evaluated for heart or heart + additional organ transplant between 2004 and 2014 at our center was performed. A machine learning decision tree model was used to evaluate multiple clinical parameters correlating with 1- and 10-year survival.

RESULTS

We identified 58 patients meeting criteria. D-transposition of the great arteries (D-TGA) with atrial switch operation (20.7%), tetralogy of Fallot/pulmonary atresia (15.5%), and tricuspid atresia (13.8%) were the most common diagnosis for transplant. Single ventricle patients were most likely to be listed for transplantation (39.8% of evaluated patients). Among a comprehensive list of clinical factors, invasive hemodynamic parameters (pulmonary capillary wedge pressure (PCWP), systemic vascular pressure (SVP), and end diastolic pressures (EDP) most correlated with 1- and 10-year outcomes. Transplanted patients with SVP < 14 and non- transplanted patients with PCWP < 15 had 100% survival 1-year post-transplantation.

CONCLUSION

For the first time, our study identifies that hemodynamic parameters most strongly correlate with 1- and 10-year outcomes in ACHD patients considered for transplantation, using a data-driven machine learning model.

Unveiling the gothic aortic arch and cardiac mechanics: insights from young patients after arterial switch operation for d-transposition of the great arteries

The arterial switch operation (ASO) has become the standard surgical treatment for patients with d-transposition of the great arteries. While ASO has significantly improved survival rates, a subset of patients develop a unique anatomical anomaly known as the gothic aortic arch (GAA). Understanding cardiac mechanics in this population is crucial, as altered mechanics can have profound consequences for cardiac function and exercise capacity. The GAA has been associated with changes in ventricular function, hemodynamics, and exercise capacity. Studies have shown a correlation between the GAA and decreased ascending aorta distensibility, loss of systolic wave amplitude across the aortic arch, and adverse cardiovascular outcomes. Various imaging techniques, including echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography, play a crucial role in assessing cardiac mechanics and evaluating the GAA anomaly. Despite significant advancements, gaps in knowledge regarding the prognostic implications and underlying mechanisms of the GAA anomaly remain. This review aims to explore the implications of the GAA anomaly on cardiac mechanics and its impact on clinical outcomes in young patients after ASO. Advancements in imaging techniques, such as computational modeling, offer promising avenues to enhance our understanding of cardiac mechanics and improve clinical management.

Risk factors for transposition of the great arteries in Saudi population

Objectives:

To assess potential risk factors and their effect on the development of transposition of the great arteries (TGA).

Methods:

A retrospective case-control study of all patients diagnosed with TGA between 1999 to 2016 at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Age and gender-matched controls were selected. Risk factors, including consanguinity, gestational diabetes, family history of congenital heart disease, parental age, and maternal parity, were collected. Regression modeling was used to analyze the effects of risk factors on the development of TGA.

Results:

A total of 206 patients with transposition of the great arteries were enrolled in the study. Transposition of the great arteries cases were divided into simple and complex TGA. Selected healthy controls were 446. In the studied cases, consanguinity was found in 95 (46%) of cases, gestational diabetes was diagnosed in 36 (17.5%) mothers, and 35 (17%) had a confirmed family history of congenital heart disease. When risk factors of the cases were compared to the controls, consanguinity, gestational diabetes, maternal age, and parity were found to significantly increase the incidence of TGA.

Conclusion:

Our study revealed significant risk factors for the development of transposition of great arteries including first degree consanguineous marriages, gestational diabetes, family history of congenital cardiac anomalies, and increasing maternal age and parity. These factors increased the risk by at least 2 folds.

Mutational analysis of the PITX2 coding region revealed no common cause for transposition of the great arteries (dTGA)

BACKGROUND

PITX2 is a bicoid-related homeodomain transcription factor that plays an important role in asymmetric cardiogenesis. Loss of function experiments in mice cause severe heart malformations, including transposition of the great arteries (TGA). TGA accounts for 5-7% of all congenital heart diseases affecting 0.2 per 1000 live births, thereby representing the most frequent cyanotic heart defect diagnosed in the neonatal period.

METHODS

To address whether altered PITX2 function could also contribute to the formation of dTGA in humans, we screened 96 patients with dTGA by means of dHPLC and direct sequencing for mutations within the PITX2 gene.

RESULTS

Several SNPs could be detected, but no stop or frame shift mutation. In particular, we found seven intronic and UTR variants, two silent mutations and two polymorphisms within the coding region.

CONCLUSION

As most sequence variants were also found in controls we conclude that mutations in PITX2 are not a common cause of dTGA.

[Piercing and tattoos in patients with congenital heart disease -- is it a problem?]

Piercing and tattooing enjoy widespread popularity in modern society. Patients with congenital heart disease are at elevated risk for infective endocarditis. However, it is not yet known whether piercing and tattooing are dangerous for these patients.A search of the literature provided 10 published cases of infective endocarditis after piercing or tattooing. Affected patients were adolescents or young adults ranging in age from 13 to 30 years (5 male, 5 female). Four of the patients had a known cardiac risk factor for endocarditis (bicuspid aortic valve, postoperative trans-position of the great arteries, postoperative coarctation, postoperative aortic valve stenosis). Piercing preceded endocarditis in 9 cases (4 times mouth, 2 ear, 1 nose, 1 breast, 1 navel), one tattoo. The following agents were isolated: S. aureus in 4 cases, 2 S. epidermidis, 1 Str. viridans, 1 Neisseria mucosa, 1 Haemophilus aphrophilus, 1 Haemophilus parainfluenzae. All patients were treated with antibiotics. Six patients underwent cardiac surgery (5 of them valve replacement). Patients with congenital heart disease constitute less than 1% of the population. Thus, they are clearly overrepresented in the published literature. Epidemiologic conclusions are not possible from these data. However, patients with congenital heart disease and their parents should be strongly advised against piercing and tattooing with regard to the risk of infective endocarditis.

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.

Hyperplastic conotruncal endocardial cushions and transposition of great arteries in perlecan-null mice

Perlecan is a heparan-sulfate proteoglycan abundantly expressed in pericellular matrices and basement membranes during development. Inactivation of the perlecan gene in mice is lethal at two developmental stages: around E10 and around birth. We report a high incidence of malformations of the cardiac outflow tract in perlecan-deficient embryos. Complete transposition of great arteries was diagnosed in 11 out of 15 late embryos studied (73%). Three of these 11 embryos also showed malformations of semilunar valves. Mesenchymal cells in the outflow tract were abnormally abundant in mutant embryos by E9.5, when the endocardial-mesenchymal transformation starts in wild-type embryos. At E10.5, mutant embryos lacked well-defined spiral endocardial ridges, and the excess of mesenchymal cells obstructed sometimes the outflow tract lumen. Most of this anomalous mesenchyme expressed the smooth muscle cell-specific alpha-actin isoform, a marker of the neural crest in the outflow tract of the mouse. In wild-type embryos, perlecan is present in the basal surface of myocardium and endocardium, as well as surrounding presumptive neural crest cells. We suggest that the excess of mesenchyme at the earlier stages of conotruncal development precludes the formation of the spiral ridges and the rotation of the septation complex in order to achieve a concordant ventriculoarterial connection. The observed mesenchymal overpopulation might be due to an uncontrolled migration of neural crest cells, which would arrive prematurely to the heart. Thus, perlecan is involved in the control of the outflow tract mesenchymal population size, underscoring the importance of the extracellular matrix in cardiac morphogenesis.

CFC1 mutations in patients with transposition of the great arteries and double-outlet right ventricle

Recent investigations identified heterozygous CFC1 mutations in subjects with heterotaxy syndrome, all of whom had congenital cardiac malformations, including malposition of the great arteries. We hypothesized that a subset of patients with similar types of congenital heart disease---namely, transposition of the great arteries and double-outlet right ventricle, in the absence of laterality defects---would also have CFC1 mutations. Our analysis of the CFC1 gene in patients with these cardiac disorders identified two disease-related mutations in 86 patients. The present study identifies the first autosomal single-gene defect for these cardiac malformations and indicates that some cases of transposition of the great arteries and double-outlet right ventricle can share a common genetic etiology with heterotaxy syndrome. In addition, these results demonstrate that the molecular pathway involving CFC1 plays a critical role in normal and abnormal cardiovascular development.

[Transposition of great arteries. Understanding its pathogenesis]

Transposition of the great arteries (TGA) is a frequent and severe cardiac defect. In patients with this malformation, diagnostic and surgical results and the long-term prognosis significantly improved in the last years. From the embryological point of view there are two main theories: 1) the anomalous infundibular rotation, and 2) the anomaly of the aortico-pulmonary septum. Both of them still present important limits. Moreover, TGA is difficult to reproduce by animal experiments, but interesting data, using retinoid acid in pregnant rats, are nowadays available, as well as there are interesting data from the epidemiologic studies on human teratologic agents. TGA is rarely associated with genetic syndromes and with additional extracardiac anomalies. A few cases are in relation with DiGeorge syndrome with deletion of chromosome 22q11. On the contrary TGA is significantly prevalent, in association with other cardiac and extracardiac anomalies, in children with lateralization defects, heterotaxy and asplenia syndrome (right isomerism). However in patients with heterotaxy and polysplenia syndrome (left isomerism) TGA is significantly more rare. In mice with mutation of Smad2 and NODAL, two genes involved in the lateralization process, some cases of TGA, with or without right isomerism of the lungs, were reported. Moreover, in families with heterotaxy some cases with congenitally corrected TGA were reported and a new gene associated with heterotaxy, CRYPTIC, can present mutations in patients with "isolated" TGA. A recent study on familiar recurrence of TGA shows in the same family some cases of TGA and of corrected TGA so that a monogenic inheritance (autosomic dominant or recessive) with variable phenotypic expression can be suggested. The normal righthand spiralization of the heart is genetically determined in cases of situs solitus and d-loop of the ventricles. This pattern is not present in cases of TGA presenting a parallel position of the great arteries. On the basis of these observations and according to new epidemiologic and genetic data some cases of TGA should be classified in the group of the anomalies of lateralization and ventricular loop. The mystery is still present but perhaps some gleams of light are appearing.

Association of transposition of the great arteries in infants with maternal exposures to herbicides and rodenticides

The Baltimore-Washington Infant Study, a case-control study of congenital heart defects in liveborn infants conducted in 1981--1989, interviewed parents about a wide range of environmental exposures that occurred during and before the pregnancy. In the period 1987--1989, the questionnaire was expanded to include a detailed inquiry about exposures to pesticides. An analysis of these latter data revealed an association of maternal exposure to any pesticides during the first trimester with transposition of the great arteries in their infants (TGA; n = 66 infants), relative to 771 control infants, with an odds ratio of 2.0 (95% confidence interval (CI): 1.2, 3.3). No other heart defects were associated with pesticides. When analyzed by type of pesticide and adjusted for covariates, there were associations of TGA with maternal exposures to herbicides (odds ratio (OR) = 2.8; 95% CI: 1.3, 7.2) and to rodenticidal chemicals (OR = 4.7; 95% CI: 1.4, 12.1) but not to insecticides (OR = 1.5; 95% CI: 0.9, 2.6). No data were collected on specific chemicals or brand names. These results raise new questions about the possible epidemiologic association of TGA with some classes of pesticides and warrant new, carefully targeted investigations.

Heterotaxia as an outcome of maternal diabetes: an epidemiological study

There are very few publications on the possible relationship between maternal diabetes and infants presenting heterotaxia-asymmetry defects. In mice, there is a relationship between maternal diabetes and heterotaxia, although this is influenced by the fetal genotype. An epidemiological analysis of heterotaxia-asymmetry in children born to diabetic mothers (diabetes mellitus or gestational diabetes) is presented here. The analysis is based in the case-control study of the ECEMC database. However, due to the very small sample size for each type of study of heterotaxia-asymmetry alterations, up to 10 control infants for each case were selected. Although the sample size is small, the results suggest that only maternal diabetes mellitus significantly increases the risk for transposition of great vessels (OR=61.87; CI:7.36-519.82), and transposition of viscera (OR=24.82; CI;1.84-335.44).

Report of a new patient with transposition of the great arteries with deletion of 22q11.2

We report on a new patient with d-transposition of the great arteries who was found to have deletion of 22q11.2. He had minor facial anomalies, normal T- and B-cell subsets, and transient hypocalcemia. Similar to rare previous reports, our patient's extracardiac manifestations were relatively mild.

Birth weight and cardiovascular malformations: a population-based study. The Baltimore-Washington Infant Study

Mean birth weights were evaluated in infants with D-transposition of the great arteries, tetralogy of Fallot, endocardial cushion defect, hypoplastic left heart syndrome, pulmonary stenosis, aortic stenosis, coarctation of the aorta, ventricular septal defect, and atrial septal defect in a population-based case-control study of congenital cardiovascular malformations in residents of Maryland, Washington, D.C., and northern Virginia (1981-1987). Study subjects were liveborn singletons without extracardiac anomalies. After adjustment for potentially confounding maternal, gestational, and infant factors, significant birth weight deficits were found for infants with tetralogy of Fallot, endocardial cushion defect, hypoplastic left heart syndrome, pulmonary stenosis, coarctation of the aorta, ventricular septal defect, and atrial septal defect. After adjustment, infants with these malformations (except coarctation of the aorta and atrial septal defect) were also significantly more likely than were controls to have low birth weight for gestational age. These findings strengthen previous evidence that certain cardiovascular malformations and low birth weight may be causally related.

Arrested rotation of the outflow tract may explain tetralogy of Fallot and transposition of the great arteries

In a previous study we investigated the rapidly changing spatial relationship of the junction of the outflow tract and great arteries in normal human embryos of Carnegie stages 15 through 19. The results suggested that the malformation complexes tetralogy of Fallot and transposition of the great arteries could be accounted for as arrests in the progression of this process of rotation. To further study this question we reviewed hearts obtained at autopsy: 28 were normal, 16 had tetralogy of Fallot, and 27 had transposition of the great arteries. The angle of the aortic to pulmonary valve axis relative to the inferior surface of the heart, as viewed from apex to base, was measured from postmortem radiographs. For normal hearts the angle was 72 degrees +/- 3 SE, 48 degrees +/- 5 for tetralogy of Fallot, and 333 degrees +/- 3 for transposition of the great arteries. Although direct comparison of hearts and embryos is difficult because of the different methods of determining angles, the valve positions in normal hearts were most similar to stage 19 embryos. Likewise, hearts with tetralogy of Fallot and transposition of the great arteries resembled stages 18 and 15, respectively. The results of the two studies are consistent with the hypothesis that tetralogy of Fallot and transposition of the great arteries arise as a result of arrests in the normal rotation of the region of the junction of the outflow tract and the great arteries.

Quantitative morphometric analysis of the pulmonary arteries in two patients with D-transposition of the great arteries and persistence of the fetal circulation

Quantitative morphometric studies were performed on the pulmonary arteries of two newborns who died at 1 and 3 days of age with both transposition of the great arteries and persistence of the fetal circulation. Similar studies were performed on two normal control subjects (age 2 and 6 days), one newborn infant (age 1 day) with secondary persistence of the fetal circulation, and one newborn infant (age 2 days) with isolated D-transposition of the great arteries, as compared to those without it. When wall thickness was related to external diameter of the vessel, the greatest difference in thickness was observed in the smallest vessels (less than 150 mu in diameter). Extension of smooth muscle peripherally and to the smallest vessels (less than 50 mu) was similarly most marked in those infants with persistence of the fetal circulation may coexist but at the same time be unrelated in a single patient. Furthermore when such coexistence is unrecognized, pharmacologic manipulation of the ductus arteriosus may be hazardous.

[Cardiological problems in the neonatal period (author's transl)]

Knowledge of the changes during transition from fetal to neonatal circulation is useful for the understanding of physiologic and pathologic variations in the neonatal cardiovascular system. Cyanosis as well as clinical symptoms of congestive heart failure in the neonate are unspecific and may represent cardiac and noncardiac disease (primary pulmonary disease, septicemia, intracranial haemorrhage or meningitis, polyglobulism). Besides detailed analysis of clinical symptoms, the examination of arterial bloodgases when breathing from room air and 100% oxygen, the electrocardiogram, the chest-roentgenogram, and the echocardiogram are of diagnostic value. Specific cardiovascular problems during the neonatal period are the patent ductus arteriosus in the premature infant and the so-called persistent fetal circulation. Among the many congenital cardiac defects potentially causing problems in the neonate the most important are complete transposition of the great arteries, coarctation of the aorta, hypoplastic left heart syndrome, and severe tetralogy of Fallot or pulmonary atresia with ventricular septal defect. With good cooperation between obstetrician, neonatologist and paediatric cardiologist, most neonates with cardiologic problems can nowadays be timely diagnosed and successfully treated.