Clinical Presentation and Therapy of d-Transposition of the Great Arteries.

d-Transposition of the great arteries (d-TGA) is the most common form of congenital heart disease that presents with cyanosis in a newborn. The aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle. It constitutes 3-5% of all congenital heart defects. In a simple d-TGA (about two-thirds of patients), there is no other cardiac abnormality other than a patent foramen ovale (PFO) and a patent ductus arteriosus (PDA). In a complex d-TGA additional cardiac abnormalities such as VSD, pulmonary stenosis or coronary abnormalities are present. About one-third to 40% of patients with d-TGA have an associated ventricular septal defect. Among patients with d-TGA, 6% of those with intact ventricular septum and 31% of those with ventricular septal defect have associated pulmonary stenosis. Coronary abnormalities are of importance with regard to the complexity of surgical repair.

Management of congenitally corrected transposition from fetal diagnosis to adulthood.

INTRODUCTION: Congenitally corrected transposition of the great arteries (ccTGA) is a rare congenital heart defect characterized by atrioventricular and ventriculo-arterial discordance. CcTGA can be diagnosed at any stage of life. The natural history of the disease depends on concomitant anomalies present in most of the cases, progression of systemic ventricular dysfunction and conduction disturbances. AREAS COVERED: This review describes diagnosis of the anomaly and summarizes the current knowledge on etiology and prognosis in ccTGA patients. Furthermore, interventional and pharmacological approaches to ccTGA management are discussed. The areas requiring further research are highlighted. EXPERT OPINION: Although advances in diagnosis and treatment continue to improve outcomes for ccTGA, patients are burdened with significant morbidity and mortality. Optimal approaches to surgical management of the anomaly, as well as prevention and management of heart failure, are still not established. Future research should focus on the long-term effect of anatomic repair, potential benefits of novel pharmacological strategies for heart failure therapy, and the optimal mode of pacing in ccTGA patients. However, the issues might be difficult to address due to rarity of the disease and its heterogenous clinical presentation. As the life-expectancy of ccTGA patients improves, acquired cardiovascular disorders will become another serious concern.

Three-dimensional-mapping-guided permanent conduction system pacing in paediatric patients with congenitally corrected transposition of the great arteries.

AIMS: In congenitally corrected transposition of the great arteries (CCTGA) the right ventricle (RV) is systemic. Atrioventricular block (AVB) and systolic dysfunction are frequently observed. Permanent pacing of the subpulmonary left ventricle (LV) may worsen RV dysfunction. The aim of this study was to seek out if LV conduction system pacing (LVCSP) guided by three-dimensional-electroanatomic mapping systems (3D-EAMs) can preserve RV systolic function in paediatric CCTGA patients with AVB. METHODS AND RESULTS: Retrospective analysis of CCTGA patients who underwent 3D-EAM-guided LVCSP. Three-dimensional-pacing map guided lead implantation towards septal sites with narrower paced QRS. Electrocardiograms (ECGs), echocardiograms, and lead parameters (threshold, sensing, and impedance) were compared at baseline (pre-implantation) and at 1-year follow-up. Right ventricle function was evaluated by 3D ejection fraction (EF), fractional area change (FAC), RV global longitudinal strain (GLS). Data are reported as median (25th-75th centiles). Seven CCTGA patients aged 15 (9-17) years, with complete/advanced AVB (4 with prior epicardial pacing), underwent 3D-guided LVCSP (5 DDD, 2 VVIR). Baseline echocardiographic parameters were impaired in most patients. No acute/chronic complications occurred. Ventricular pacing was >90%. At 1-year follow-up QRS duration showed no significant changes compared with baseline; however, QRS duration shortened in comparison with prior epicardial pacing. Lead parameters remained acceptable despite ventricular threshold increased. Systemic RV function was preserved: FAC and GLS improved significantly, and all patients showed normal RV EF (>45%). CONCLUSION: Three-dimensional-EAM-guided LVCSP preserved RV systolic function in paediatric patients with CCTGA and AVB after short-term follow-up.

Outcomes and factors associated with early mortality in pediatric postcardiotomy veno-arterial extracorporeal membrane oxygenation.

Mortality and morbidity of children received veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support after cardiac surgery remain high despite remarkable advances in medical management and devices. The purpose of this study was to describe outcomes and risk factors of applying VA-ECMO in the surgical pediatric population. We retrospectively analyzed 85 consecutive pediatric patients (aged <18 years) who received postcardiotomy VA-ECMO from January 2010 to December 2018. Median (IQR) age at ECMO implantation in this cohort was 12.7 (6.4, 43.2) months, median weight was 8.5 (6.0, 12.8) kg, mean ECMO duration was 143.2 ± 81.6 hours and mean hospital length of stay was 48.4 ± 32.4 days. Seventy-five patients (88.2%) were indicated for postcardiotomy cardiogenic shock. The successful ECMO weaning rate was 70.6% and in-hospital mortality was 52.9%. The most common diagnosis was transposition of great arteries (n = 18, 21.2%), while acute kidney injury occurred most often (n = 64, 75.3%). Multivariate logistic regression analysis showed that thrombocytopenia, hemolysis, and nosocomial infection were positively correlated with in-hospital mortality. Multivariate Cox proportional hazard regression analysis presented that thrombocytopenia significantly increased the 180-day mortality in patients with successful weaning. Therefore, multiple factors had adverse effects on prognosis. Patient selection and procedures from ECMO implantation to weaning need to be closely monitored and performed in a timely manner to improve outcome.

Perinatal and perioperative factors associated with mortality and an increased need for hospital care in infants with transposition of the great arteries: A nationwide 11-year population-based cohort.

INTRODUCTION: Newborn infants with transposition of the great arteries (d-TGA) need immediate care for an optimal outcome. This study comprised a nationwide 11-year population-based cohort of d-TGA infants, and assessed whether the implementation of a nationwide systematic fetal screening program, or other perinatal, or perioperative factors, are associated with mortality or an increased need for hospital care. MATERIAL AND METHODS: The national cohort consisted of all live-born infants with simple d-TGA (TGA ± small ventricular septal defect, n = 127) born in Finland during 2004-2014. Data were collected from six national registries. Prenatal diagnosis and perinatal and perioperative factors associated with mortality and length of hospitalization were evaluated. RESULTS: Preoperative mortality was 7.9%, and the total mortality was 8.7%. The prenatal detection rate increased after introducing systematic fetal anomaly screening from 5.0% to 37.7% during the study period (P < .0001), but the total mortality rate remained unchanged. All prenatally diagnosed infants (n = 27) survived. Lower gestational age (odds ratio 0.68, P = .012) and higher maternal age at birth (odds ratio 1.16, P = .036) were associated with increased mortality in multivariable analysis. Older infant age at time of operation (P = .002), longer aortic clamp time (P < .001), and higher maternal body mass index (P = .027) were associated with longer initial hospital stay. An extended need for hospital care during the first year of life was multi-factorial. CONCLUSIONS: In our cohort, none of the prenatally diagnosed d-TGA infants died. As a result of the limited prenatal detection rates, however, the sample size was insufficient to reach statistical significance. The d-TGA infants born with lower gestational age and to older mothers had increased mortality.

Prenatal Diagnosis of Transposition of the Great Arteries Reduces Postnatal Mortality: A Population-Based Study.

BACKGROUND: Transposition of the great arteries (TGA) may present as a life-threatening neonatal malformation. Although prenatal detection facilitates the perinatal management, the impact on outcome is controversial. METHODS: This study reviewed the differences in prenatal diagnosis of TGA from 2009 to 2014 among the 5 geographic areas in Ontario and compared the management, morbidity, and mortality among neonates with a prenatal (prenatal cohort; n = 70) vs a postnatal (postnatal cohort; n = 76) anomaly diagnosis. Cases were identified from prospective databases of the provincial cardiac tertiary centres and the coroner's office. RESULTS: Prenatal TGA detection rates varied significantly among areas (median: 50%; range: 14% to 72%; P = 0.03). Compared with the postnatal cohort, time from birth to tertiary care admission (1.4 vs 10.4 hours, P < 0.001), prostaglandin therapy (0.1 vs 5.3 hours; P < 0.001), balloon atrial septostomy (5.3 vs 14.9 hours; P <0.001), and arterial switch operation (6 vs 9 days, P = 0.002) was significantly shorter in the prenatal cohort. Although other preoperative variables-including the need of ventilation and mechanical support, morbidity score, and lowest pH and preductal oxygen saturations-were comparable, a prenatal diagnosis was associated with improved 1-year survival (odds ratio: 0.108; 95% confidence interval, 0.013-0.88; P = 0.0184). CONCLUSIONS: Prenatal diagnosis of TGA significantly shortened time intervals from birth to neonatal care and surgery and was associated with improved survival. The prenatal detection rate of TGA in Ontario was low (50% or less) outside of Metropolitan Toronto, suggesting the need for new strategies to further improve intraprovincial detection rates.

Management of the Adult Patient With Congenitally Corrected Transposition: Challenges and Uncertainties.

Congenitally corrected transposition (ccTGA) is a rare form of congenital heart disease characterized by atrioventricular and ventriculoarterial discordance. Patients with ccTGA usually have associated congenital cardiovascular conditions; less than 1% have no associated lesions. Generally, ccTGA is identified during infancy or childhood with features of heart failure or cyanosis when there are associated lesions such as ventricular septal defect and/or pulmonic stenosis. Presentation later in life generally occurs when there are either mild or no associated lesions. Presentation during adulthood may be prompted by symptoms or signs of cardiovascular disease or due to abnormal findings on cardiac testing. Management of patients with ccTGA depends on presentation, symptoms, and associated defects. In this review, we will focus on the management of adult patients with ccTGA.

Mechanical Support for Patients With Congenitally Corrected Transposition of the Great Arteries and End-Stage Ventricular Dysfunction.

Despite great advances in caring for patients with congenitally corrected transposition of the great arteries (ccTGA), a high proportion of these patients go on to develop heart failure and death in early adulthood. Adults with congenital heart disease (ACHD) only comprise a small number of patients receiving ventricular assist devices (VAD), but ccTGA accounted for 36% of ACHD patients in the INTERMACS database. Review of the literature describing ccTGA patients receiving VAD therapy shows promising results. With newer devices and the assistance of advanced imaging, mechanical circulatory support is becoming a desirable option for this population of patients and has the potential to provide significant long-term support, relieving them of heart failure symptoms and delaying and perhaps in the future avoiding, the need for cardiac transplantation.

Implantation techniques and outcomes after cardiac resynchronization therapy for congenitally corrected transposition of the great arteries.

BACKGROUND: Patients with congenitally corrected transposition of the great arteries (CCTGA) are at risk of congestive heart failure (CHF). There are limited data on cardiac resynchronization therapy (CRT) techniques and long-term outcomes in this population. OBJECTIVE: The purpose of this study was to determine implantation techniques and efficacy of CRT for CCTGA. METHODS: A 15-year retrospective review of patients with CCTGA undergoing CRT was performed. RESULTS: Twenty patients were identified (mean age 40.1 ± 15.3 years; baseline New York Heart Association class 2.0 [interquartile range 1.5-3.5]). Indication was pacing-induced ventricular dysfunction in 12 (60%), atrioventricular block with anticipation for >40% ventricular pacing in 5 (25%), and intact atrioventricular conduction with CHF and QRS prolongation in 3 (15%). A transvenous approach was successful in 18 of 19 patients (95%) in whom it was attempted, with cannulation of a posteroseptal ostium in 14 (78%), vein of Marshall in 2 (11%), and superior ectopic ostium in 2 (11%). Of patients with baseline CHF, 8 (67%) were acute responders, with loss of response in 2 patients (median 1.1 and 1.5 years, respectively). Of 4 patients referred for heart transplantation, 3 (75%) could be de-listed following CRT. Only lead location in the right ventricular outflow tract predicted poor CRT response (P = .026). Post-procedure, the QRS duration increased by 4.3 ms/y (P < .001) despite stable pacing characteristics. CRT revision was required in 4 patients for infection (n = 2) or phrenic nerve capture (n = 2) and was associated with loss of CRT response in 1 patient. CONCLUSION: A transvenous approach to CRT involving distinct coronary venous patterns is feasible for most patients with CCTGA anatomy. Long-term outcome is favorable, but is characterized by return of right ventricular dysfunction in some patients.

Successful preoperative bridge with extracorporeal membrane oxygenation in three neonates with D-transposition of the great vessels and pulmonary hypertension.

Pulmonary hypertension with transposition of the great arteries is associated with significant morbidity and mortality. At the worst end of the spectrum are patients who undergo extracorporeal support perioperatively. We describe our experience with three patients who received preoperative extracorporeal support and separated from cardiopulmonary bypass successfully on conventional postoperative care, with no significant deficits on follow-up.

Rhythm disturbances and treatment strategies in children with congenitally corrected transposition of the great arteries.

BACKGROUND: We aimed to evaluate rhythm abnormalities in cases of congenitally corrected transposition of the great arteries (ccTGA) and associated treatment strategies. PATIENTS AND METHODS: This retrospective cohort study included 65 pediatric patients with ccTGA who were admitted to the clinic between 2009 and 2017. The patients were divided into two groups, and surgical data, Holter electrocardiographic (ECG) recordings, ECG recordings, electrophysiological data, and device implantation data on the two groups were compared. RESULTS: Group I (n = 53, 82%) consisted of patients with significant associated lesions, and Group II (n = 12, 18%) consisted of those with minor or no associated lesions (isolated ccTGA). Rhythm abnormalities were diagnosed in 22 (34%) of the patients based on initial ECG findings and Holter ECG recordings. Eleven (17%) of these patients had atrioventricular (AV) block of different degrees, and the other 11 (17%) had supraventricular arrhythmia (SVA). The median follow-up was 49 months (range, 9-89 months), and the rhythm remained normal in 26 (42%) of the patients. Three patients died on follow-up. Of 40 patients with normal initial findings, nine required pacemaker implantation due to complete heart block, and SVA developed in seven patients on follow-up. No ventricular tachycardia was seen initially or on follow-up. Ablation was performed in four patients. During the follow-up period, pacemakers were implanted in 12 (23%) of patients in Group I and 4 (33%) of patients in Group II due to complete heart block. Cardiac resynchronization therapy (CRT) was performed in four patients due to systemic ventricular dysfunction. Notably, all four of these patients had a pacemaker implanted postoperatively.

Development of quality metrics for ambulatory pediatric cardiology: Transposition of the great arteries after arterial switch operation.

OBJECTIVE: To develop quality metrics (QMs) for the ambulatory care of patients with transposition of the great arteries following arterial switch operation (TGA/ASO). DESIGN: Under the auspices of the American College of Cardiology Adult Congenital and Pediatric Cardiology (ACPC) Steering committee, the TGA/ASO team generated candidate QMs related to TGA/ASO ambulatory care. Candidate QMs were submitted to the ACPC Steering Committee and were reviewed for validity and feasibility using individual expert panel member scoring according to the RAND-UCLA methodology. QMs were then made available for review by the entire ACC ACPC during an "open comment period." Final approval of each QM was provided by a vote of the ACC ACPC Council. PATIENTS: Patients with TGA who had undergone an ASO were included. Patients with complex transposition were excluded. RESULTS: Twelve candidate QMs were generated. Seven metrics passed the RAND-UCLA process. Four passed the "open comment period" and were ultimately approved by the Council. These included: (1) at least 1 echocardiogram performed during the first year of life reporting on the function, aortic dimension, degree of neoaortic valve insufficiency, the patency of the systemic and pulmonary outflows, the patency of the branch pulmonary arteries and coronary arteries, (2) neurodevelopmental (ND) assessment after ASO; (3) lipid profile by age 11 years; and (4) documentation of a transition of care plan to an adult congenital heart disease (CHD) provider by 18 years of age. CONCLUSIONS: Application of the RAND-UCLA methodology and linkage of this methodology to the ACPC approval process led to successful generation of 4 QMs relevant to the care of TGA/ASO pediatric patients in the ambulatory setting. These metrics have now been incorporated into the ACPC Quality Network providing guidance for the care of TGA/ASO patients across 30 CHD centers.

A great imitator in adult cardiology practice: congenitally corrected transposition of the great arteries.

INTRODUCTION: Congenitally corrected transposition of the great arteries (ccTGA) is a rare congenital disease that frequently remains undiagnosed until adulthood, especially when there is an absence of other congenital anomalies. Adults with ccTGA may remain asymptomatic and their diagnosis could be missed on initial evaluation, or it could be diagnosed incidentally as an evaluation of murmur. We aim to report the different presentations of ccTGA in eight adult patients and review the key features required to suspect the diagnosis during an initial visit. CASES: We present some illustrative cases of ccTGA patients who had diverse presentations ranging from being completely asymptomatic to presenting with an acquired heart disease resulting in sudden cardiac arrest. Overall, most of these patients had isolated ccTGA with no other significant associated cardiac anomalies and were either undiagnosed or lost to follow-up until adulthood. These case illustrations represent the challenges confronted in adult practices when patients with unrecognized ccTGA present during an initial visit. CONCLUSIONS: Congenitally corrected transposition of the great arteries poses a challenge in the adult cardiology practice because of its diverse clinical presentation. It is crucial that internists, cardiologists, and sonographers maintain a high degree of suspicion after meticulous physical examination for the early recognition of ccTGA, and thus avoid associated morbidities. Through some case examples, we provide clues to the key diagnostic features that could help them to be vigilant in making a diagnosis.

Prenatal Echocardiographic Assessment of Foramen Ovale Appearance in Fetuses with D-Transposition of the Great Arteries and Impact on Neonatal Outcome.

INTRODUCTION: Neonates with D-transposition of the great arteries (dTGA) may die at birth because of the inadequate intracardiac mixing due to a misdiagnosed restrictive foramen ovale. We reviewed our experience in echocardiographic assessment and perinatal management of fetuses with dTGA searching for new features that may predict the need for urgent balloon atrial septostomy (BAS) immediately after birth. PATIENTS AND METHODS: We included fetuses diagnosed with dTGA between January 2000 and December 2014. We assessed pre- and postnatal appearance of the foramen ovale, ductus arteriosus and pulmonary veins. Both the diagnostic findings at the time of last prenatal echocardiogram and those findings deriving from a retrospective reevaluation of stored videos were considered. BAS was defined as urgent if performed in neonates with restrictive foramen ovale and severe hypoxemia. RESULTS: We reviewed 40 fetuses with dTGA. 20/40 fetuses received urgent BAS at birth. Not only the restrictive but also the hypermobile and the redundant appearance of the foramen ovale was significantly associated with urgent BAS (p < 0.0001, p = 0.002 and p = 0.0001, respectively). CONCLUSIONS: Prenatal evaluation of the foramen ovale appearance in fetuses with dTGA is still challenging. Based on our experience, also the redundant foramen ovale appearance may need urgent BAS at birth.

Internal Cardioverter Defibrillator Indications and Therapies after Atrial Baffle Procedure for d-Transposition of the Great Arteries: A Multicenter Analysis.

BACKGROUND: Sudden cardiac death (SCD) is the most important cause of late mortality after atrial baffle procedure for d-transposition of the great arteries (d-TGA). Experience with internal cardioverter defibrillator (ICD) therapy in this population is limited. We conducted a multicenter cohort study to determine the current state of ICD therapy in individuals after atrial baffle procedure. METHODS: Demographic and clinical data as well as data on device implantation, programming, ICD discharges, and complications after atrial baffle procedure for d-TGA from four German centers were analyzed retrospectively. RESULTS: ICD implantation was undertaken in 33 subjects. ICD implantation was undertaken as primary prevention in 29 (88%) and secondary prevention in four (12%) individuals. There were 21 (64%) subjects with atrial reentrant tachycardia (IART). During a median follow-up of 4.8 years, seven appropriate ICD therapies were delivered in three (10%) individuals with primary prevention indication. No appropriate shocks were documented in subjects with secondary prevention indication. A total of 12 inappropriate ICD discharges occurred in eight (24%) individuals due to IART (n = 6) or lead failure (n = 2). ICD-related complications were noted in seven individuals (21%): lead dislodgement/failure in five (15%) and ICD infection in two subjects (6%). CONCLUSIONS: The majority of individuals received an ICD for primary prevention of SCD, thus representing a liberal attitude of physicians for ICD implantation. During a median follow-up of 4.8 years, the rate of appropriate ICD therapies was low and clearly exceeded by inappropriate ICD discharges. Lead failure and IART were present in >20% of the individuals and were frequent reasons for inappropriate ICD discharges. Facing these results, rigorous treatment of IART and careful ICD programming seems mandatory.

Contemporary Hospitalization Rate Among Adults With Complex Congenital Heart Disease.

BACKGROUND: Adults with congenital heart disease are hospitalized at increasing rates in the Western world. Identification of rates of and risk factors for hospitalization is essential for research and improving patient outcomes. METHODS: We conducted a single-center retrospective analysis of patients with a primary diagnosis of tetralogy of Fallot (TOF), transposition of the great arteries (both d- and l-transposition of the great arteries [TGAs]), or single ventricle (SV). We investigated the rates of mortality, annual hospitalization, and patient-specific risk factors for unplanned cardiac hospitalization. RESULTS: Adult patients with complex congenital heart disease are hospitalized at a rate four to eight times greater than the general US population (P < .001). In addition, there are significant differences between the rates of hospitalization in TOF and TGA (0.39 and 0.41 hospitalizations per patient-year, respectively) and SV (0.72 hospitalizations per patient-year). The majority of excess hospitalizations in the study group were due to cardiac disease (P < .001 for all three groups). Risk factors for unplanned cardiac hospitalization in TOF included pulmonary atresia, depressed left ventricular and right ventricular ejection fraction, and smoking; in TGA, they included Ebstein malformation, surgeries other than primary repair, noncardiac diagnoses, atrial arrhythmias, atrioventricular nodal block, left ventricular ejection fraction, and smoking; and in SV, they included atrial arrhythmias and cyanosis. CONCLUSIONS: Patients born with complex congenital heart disease are hospitalized far more frequently than the general US population, primarily for cardiac-related illness. Future research should focus on confirming the present findings and on identification of strategies to improve outcomes in this growing group of patients.