Systemic Right Ventricle, Transposition of the Great Arteries
Conditions
Keywords
Long-term outcome, Heart failure, Arrhythmias, Mortality
Brief summary
Patients with the transposition of great arteries (TGA) who undergo atrial switch operation and congenitally corrected TGA (ccTGA) patients have the right ventricle as their systemic ventricle. Function of the systemic right ventricle (SRV) could deteriorate which is associated with impaired prognosis. It is of paramount importance to understand the course and fate of these patients during a long-term follow-up to identify the determinants of adverse outcomes.
Detailed description
In the year 2000, the prevalence of congenital heart diseases (CHD) patients with transposition of great arteries (TGA) was 0.027% in living children and 0.004% in living adults (1). Considering a complete transition to arterial switch operation in the 1990s, it is expected that the number of patients with systemic right ventricle (SRV) decrease over time (2). However, considering the existing number of patients with the TGA who have not undergone arterial switch surgery, SRV remains a challenging issue in the practice of adult congenital heart disease (ACHD) specialists. TGA is characterized by AV concordance and ventriculo-arterial discordance and is called simple without the presence of associated congenital anomalies. However, complex TGA is when other anomalies are present including VSD (∼45%), LVOTO (∼25%), and CoA (∼5%). TGA's pathogenesis is controversial and there is rare familial occurrence. Male are two times more affected than females. The prognosis of TGA patients without surgery is poor and only exceptional cases survive to adulthood (3). Heart failure and sudden cardiac death (SCD) are the predominant causes of mortality in TGA patients (4). Patients who undergo atrial switch operation and congenitally corrected TGA (ccTGA) patients are at risk of developing SRV failure in the future (3). The RV is a thin-walled triangular structure acting as a low pressure pump in the normal heart. Because of having only 2 layers, the RV cannot cause the torsion caused by the LV. Due to this geometry and anatomy, the right ventricular function is highly dependent on the loading conditions. The increased afterload that the RV faces in the systemic position causes compensatory RV dilation to maintain the stroke volume. Subsequently, there is increased myocardial wall stress and oxygen demand. The development of heart failure in the SRV is multifactorial. Other potential factors contributing to the SRV failure are impaired coronary reserve or ischemia, myocardial fibrosis, chronotropic incompetence, volume overload from tricuspid regurgitation and arrhythmias (4). Another contributing factor is the reduced baffle compliance in patients with atrial switch. This impairs the preload and stroke volume, especially when there is increased demand. The non-contractile atrial baffles cause impaired atrioventricular transport during tachycardia, therefore causing an inadequate RV filling (4). Unfortunately, at the moment, the hypothesis that angiotensin-converting enzyme inhibitors (ACE inhibitors), angiotensin II receptor blockers (ARBs), aldosterone antagonists, and beta-blockers can improve the outcome of such patients alone or in combination is not supported by data and evidence. There is no solid recommendation in the 2020 guidelines for the management of ACHD (3). Previous studies evaluating the fate and outcome of patients with an SRV are either mostly single-centered with a small number of patients or have a short follow-up period (5,6). In a study done by Richard Dobson and colleagues on a national cohort in Scotland, the investigators concluded that patients with an SRV who survive to adulthood have low mortality and good functional status up to the age of 40 (7). It is of paramount importance to understand the course and fate of these patients during a long-term follow-up to identify the determinants of adverse outcomes. This will enable the investigators to investigate mechanistic pathways of such outcomes. By understanding the risk factors and pathophysiological basis, the investigators can also investigate new diagnostic methods and therapeutic options to improve the quality of life and reduce the mortality of patients with an SRV.
Interventions
None listed
Sponsors
Hartekind
Hartstichting
University Medical Center Groningen
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
12 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients aged 12 years old and older * Surgically corrected transposition of the great arteries (TGA) patients with a systemic right ventricle (SRV) (Mustard, Senning) * Congenitally corrected TGA patients with a systemic right ventricle
Exclusion criteria
\* None.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of patients with device implantation | Through study completion, an average of 18 years | Including pacmakers, ICDs and CRTs. |
| Number of patients with pulmonary artery hypertension | Through study completion, an average of 18 years | Mean PAP of more than 25mmHg or systolic PAP of more than 40 mmHg. |
| Number of patients with baffle interventions | Through study completion, an average of 18 years | Surgical or angiographic reintervention of baffles in patients with surgically corrected transposition of the great arteries (due to stenosis or leakage). |
| Number of patients with coronary artery interventions | Through study completion, an average of 18 years | Due to ischemia. Angiographic or surgical intervention. |
| All-cause mortality | Through study completion, an average of 18 years | Death |
| Incident heart failure | Through study completion, an average of 18 years | Initiation or increase in dosage (if previously prescribed for another cause, i.e. hypertension) of loop diuretic, ACE-inhibitor/ARB therapy, or evidence-based beta blocker therapy because of new heart failure signs and symptoms (shortness of breath, fatigue, reduced exercise tolerance) AND AT LEAST 1 OF THE FOLLOWING: • BNP ≥400 pg/mL OR the following NT-proBNP levels according to age: \< 50 years, ≥450 ng/L; 50-75 years, ≥900 ng/L; \>75 years, ≥1800 ng/L OR systolic dysfunction (Systemic ventricle EF \<50%) OR • BNP 100-400 pg/mL (or NT-proBNP levels below the thresholds according to age given above) AND structural or functional heart disease |
| Number of patients with heart failure hospitalization | Through study completion, an average of 18 years | Rehospitalization, emergency ward visit, 24h observation stay AND Treatment with or increase in dosage if previously prescribed for another cause (i.e.hypertension) of loop diuretics or treatment with IV vasoactive agents. |
| Number of patients with arrhythmias | Through study completion, an average of 18 years | Events that cause emergency ward visit or hospitalization. |
| Number of patients with thromboembolic events | Through study completion, an average of 18 years | Cerebrovascular events including any of (Hemorrhagic or ischemic): 1, TIA (symptoms less than 24 hours) 2, CVA (symptoms more than 24 hours) and also pulmonary embolism. |
| Infective endocarditis | Through study completion, an average of 18 years | Definitie Infective Endocarditis |
| Number of patients with tricuspid valve surgery | Through study completion, an average of 18 years | Tricuspid valve surgery |
| Number of patients with ventricular Assist Device implantation | Through study completion, an average of 18 years | Implantation of ventricular assist device |
| Number of patients with heart transplantation | Through study completion, an average of 18 years | Heart transplantation |
| Number of patients with aortic aneurysm or dissection | Through study completion, an average of 18 years | Aortic root more than 40 mm or aneurysm in other parts of aorta. Aortic dissection. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of patients with right ventricular systolic dysfunction | At two time points. 1: Baseline 2. Through study completion, an average of 18 years | Measured by echocardiography qualitatively |
| Number of patients with left ventricular systolic dysfunction | At two time points. 1: Baseline 2. Through study completion, an average of 18 years | Measured by echocardiography qualitatively |
| Number of patients with decreased exercise capacity | At two time points. 1: Baseline 2. Through study completion, an average of 18 years | Evaluated by cardiopulmonary exercise test results. |
Countries
Belgium, Netherlands
Outcome results
None listed