Early Versus Later Re-valving in Tetralogy of Fallot With Free Pulmonary Regurgitation - Combined Cross-sectional and Prospective, Multi-centre, Randomized, Parallel-group Clinical Trial
Phase: NA
Conditions: Tetralogy of Fallot, Pulmonary Regurgitation
Sponsor: Rigshospitalet, Denmark

 
Projektidentifikation: H-18016868 
 
 
 
 
 
 
Early Versus Later Re-valving in 
Tetralogy of Fallot with Free Pulmonary Regurgitation 
 
Combined cross-sectional and prospective, multi-centre, randomized, parallel-group clinical trial 
evaluating the efficacy and safety of early re-valving in patients with Tetralogy of Fallot and free 
pulmonary regurgitation compared to current guideline practice 
 
 
 
 
 
 
 
 
National Danish research project involving: 
 
 
Rigshospitalet, Copenhagen 
 
Odense University Hospital 
 
Aarhus University Hospital 
 
 
 
 
 
 
 
Contact person: 
 
 
Lars Søndergaard 
 
Professor of Cardiology, DMSc 
 
The Heart Centre, Section 2011 
 
Rigshospitalet 
 
Blegdamsvej 9 
 
2100 Copenhagen, Denmark 
 
E-Mail: lars.soendergaard.01@regionh.dk 
 
Phone: +45 35458693 (work), +45 28777161 (private) 

 
 
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Table of Contents 
 
Background 
 
Study design 
 
Sub-study I: Cross-sectional evaluation of the impact of long-standing severe pulmonary regurgitation after 
initial repair of Tetralogy of Fallot 
 
Sub-study II: Randomized clinical trial comparing an early and later re-valving strategy 
 
Safety and ethical aspects 
 
Time schedule 
 
Study organization 
 
Research staff 
 
Participant recruitment  
 
PhD studies 
 
Permissions 
 
Equipment 
 
Reimbursement 
 
Budget and funding 
 
Summary 
 
Additional considerations regarding the inclusion criteria and additional information about clinical and 
paraclinical test procedures 
 
References 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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Appendices 
 
Appendix 1: Additional considerations regarding the inclusion criteria and additional information about 
 
clinical and paraclinical test procedures 
 
Appendix 2:  Abbreviated study protocol 
 
 
Appendix 3:  Appendices for sub-study 1 
 
 
Patient information for adults (Deltagerinformation til voksne) 
 
 
 
Patient information for patients aged 15-17 (Deltagerinformation til 15- til 17-årige) 
 
 
 
Patient information for children (Deltagerinformation til børn) 
 
 
Consent form for adults (Samtykkeerklæring til voksne) 
 
 
Consent form for children (Samtykkeerklæring til børn) 
 
 
Medical power of attorney form (Fuldmagtserklæring) 
 
 
Appendix 4:  Appendices for sub-study 2 
 
 
Patient information for adults (Deltagerinformation til voksne) 
 
 
 
Patient information for patients aged 15-17 (Deltagerinformation til 15- til 17-årige) 
 
 
 
Patient information for children (Deltagerinformation til børn) 
 
 
Consent form for adults (Samtykkeerklæring til voksne) 
 
 
Consent form for children (Samtykkeerklæring til børn) 
 
 
Medical power of attorney form (Fuldmagtserklæring) 
 
Appendix 5:  Questionnaires 
 
 
EQ-5D-3L 
 
 
EQ-5D-Y 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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Background 
 
Anatomy and classification 
 
Tetralogy of Fallot (ToF) is a congenital heart disease (CHD) characterized by four anatomic features, 
consisting of 1) ventricular septal defect (VSD), 2) pulmonary stenosis and 3) dextroposition of the aorta, 
which arise due to anterior and cephalad deviation of the infundibular septum and 4) right ventricular 
hypertrophy. The anatomy was first discovered by the Danish anatomist Steno in 1673 and later described 
more specifically by Fallot in 1888. Four anatomic variants of ToF are considered by The International 
Society for Nomenclature of Paediatric and Congenital Heart Disease and outlined in The International 
Paediatric and Congenital Cardiac Code: 1) ToF with pulmonary stenosis, 2) ToF with pulmonary atresia, 3) 
ToF with common atrioventricular canal and 4) ToF with absent pulmonary valve. Tof with pulmonary 
stenosis which is the most common type will be addressed in this study. 
 
Etiology and genetics 
 
Although ToF may present af part of a known syndrome, this lesion typically occurs sporadically without 
other anomalies. In a study of 114 patient with non-syndromic ToF, 4 % had mutations in transcription 
factor NKX2.5, which appears to have a role in cardiac development. In genome-wide surveys of patients 
with non-syndromic ToF and their parents, de novo copy number variants were estimated to be present in 
approximately 10 % of sporadic cases of ToF compared with less than 0.1 % in controls at several 
chromosomal locations. Several reports have associated ToF with mutations in TBX1 and ZFPM2. MTHFR 
polymorphisms have also been associated with an increased risk of ToF development.  
 
Further investigation is required to determine the roles of these mutations and polymorphisms in the 
evolution of ToF.  
 
Approximately 15 % of patients with ToF present with associated syndromes: 
 
1) Down syndrome (trisomy 21) 
2) Alagille syndrome (JAG1 mutations). ToF as sole manifestation of JAG1 mutations without other evidence 
of Alagille syndrome has also been reported. 
3) DiGeorge and velocardiofacial syndromes (deletions on chromosome 22q11). There may be susceptibility 
genes for ToF within the latter region of chromosome 22q11 in children without extracardiac anomalies, 
and 22q11.2 deletions syndrome is unrecognized in many adult patients with ToF. In one study patients 
with 22q11 deletion had worse surgical outcomes due to less favorable anatomy of the pulmonary arteries. 
 
Identification of disease-related genes and associated syndromes provides critical information for diagnosis 
and a fundamental understanding of cardiac development, as well as important information for counselling 
of patients with ToF or their parents. 
 
Epidemiology 
 
CHD is the leading cause of infant mortality and the most common congenital malformation, accounting for 
about one third of all congenital anomalies.1–3 The best estimate of birth prevalence for CHD based on large 
systematic reviews is 8-9 per 1.000 live births, corresponding to 1.35 million newborn worldwide with CHD 
every year1,4. Due to the last 70 years of progress in diagnosis, management and care of patients with CHD, 
the majority of affected children reach adulthood, which has resulted in a substantial rise in prevalence of 
grown-ups with congenital heart diseases (GUCH) over the last decades, with growth estimates around 3-5 

 
 
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% annually.5,6 As such CHD represent a major global health burden. There is some evidence that we might 
see a further increase in the birth prevalence of CHD as rising numbers of women in the western world 
delay childbearing age and as the offspring of the growing GUCH population is at higher risk of congenital 
heart anomalies.7,8 Fetal echocardiography is emerging as an important element in ante- and postnatal 
treatment of structural heart diseases.9 Nevertheless, the impact on incidence and prevalence of CHD has 
yet to be evaluated. In a novel, as yet unpublished Danish study (Rebbekka Lytzen, PhD thesis) the 
termination rate of pregnancies diagnosed with ToF from 1996 to 2013 was only 7 %. Even though we 
expect antenatal detection rates for CHD to increase with advances in ultrasound screening, it remains 
questionable whether termination rates will rise proportionally in case of isolated well-manageable 
anomalies such as ToF, with an ever-improving prognosis. The worldwide development in birth prevalence 
of the most common CHD subtypes is displayed in Figure 1. One should note the ongoing increase for 
almost every CHD subtype. 
 
Figure 1. Time Course of the Eight Most Common Congenital Heart Disease Subtypes From 1945 to 2010.  
 
 
 
AoS = aortic stenosis; ASD = atrial septal defect; Coarc = coarctation; PDA = patent ductus arteriosus; PS = pulmonary stenosis; 
TGA = transposition of the great arteries; TOF = Tetralogy of Fallot; VSD = ventricular septal defect. 
 
 
Adapted from "Birth Prevalence of Congenital Heart Disease Worldwide", Van der Linde et al., Journal of The American College of 
Cardiology, 2011, Volume 58).4 
 
 
A birth prevalence of 2-5 per 10.000 live births is reported for ToF in international studies.1,4 According to 
the Danish National Patient Registry there are currently 1.170 patients with Tetralogy of Fallot in Denmark. 
55 % are male and 45 % are female with a median age of 26 years (25th to 75th percentile: 14-42 years) 
(Figure 2). 

 
 
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Age 
Figure 2. Age distribution of patients with Tetralogy of Fallot in Denmark. The %age of the different male (blue bars) 
and female (red bars) age groups of the total male and female cohort are displayed on the X-axis. The age groups are 
displayed on the Y-axis.  
 
 
        %age of male individuals 
          %age of female individuals 
 
The median number of liveborn with ToF per year in Denmark between 1970 when echocardiography 
became widely available in clinical practice, to 2017 was 26 (25th to 75th percentile: 23-33 liveborn with 
ToF) (Figures 3 and 4). 
 
Figure 3. Liveborn with Tetralogy of Fallot in Denmark (1900 - 2017). The corresponding year is displayed on the X-
axis and the total number of liveborn each year on the Y-axis. The years with the lowest and highest number of 
liveborn with ToF are hightlighted with red. 
 
 
15
10
5
0
5
10
15
0-4 år
10-14 år
20-24 år
30-34 år
40-44 år
50-54 år
60-64 år
70-74 år
80-84 år
2423
18
16
19
22
33
23
31
24
3635
28
2324
30
24
40
333233
42
24
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323334
22
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31
3334
25
23
21
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24
22
18
16
13
17
0
10
20
30
40
50
60
▪ 
Male 
▪ 
Female 

 
 
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Figure 4. Liveborn with Tetralogy of Fallot in Denmark per 10.000 Live Births (1970-2017). The median number of 
liveborn with Tetralogy of Fallot per year aggregated for different periods and median number of liveborn with 
Tetralogy of Fallot per 10.000 live births is displayed on the X-axis. The different time periods are displayed on the Y-
axis. 
 
 
Management  
 
Successful surgical therapy using a palliative subclavian-to-pulmonary-artery shunt was first reported by 
Blalock and Taussig in 1945. Almost ten years later the first intra-cardiac corrective repairs with resection of 
the pulmonary stenosis and closure of the VSD were performed by Lillehei in 1954, using another patient as 
oxygenator during surgery, and by Kirklin in 1955 using a pump oxygenator. In 1959 Warden and Lillehei 
introduced the use of a patch for enlargement of the right ventricular outflow tract (RVOT) and 
subsequently the first reconstruction with an aortic homograft was performed by Ross and colleagues in 
1966. RVOT reconstructions with valved conduits were first performed in Denmark in the 1970's. In the 
current era, most patients undergo intra-cardiac repair during the first year of life. This is often done by 
VSD-closure witch a patch, resection of the subvalvular pulmonary stenosis and commissurotomy of the 
pulmonary valve. However, in up to 50 % of the patients the pulmonary annulus is too small and a 
transannular patch (TAP) is inserted to achieve relief of outflow tract obstruction,  although resulting in 
severe/free pulmonary regurgitation (PR).10 In some of these patients valve-sparing repair is applied instead 
of using a TAP, although this approach is associated with the risk of residual pulmonary stenosis when used 
in case of a small RVOT.11 Furthermore, although early outcomes after valve-sparing surgery might seem 
favourable, studies suggest that over time most patients experience PR in the same range as those repaired 
with a TAP. Extra-cardiac palliative shunts are no longer commonly applied, but may be needed in infants 
with severe outflow tract obstruction who are not suited for intra-cardiac repair (i.e. due to prematurity or 
small pulmonary arteries) or in those with anatomic variants (i.e. ToF with pulmonary atresia). Later in life, 
most patients require RVOT reconstruction with a valved conduit due to symptoms arising from 
longstanding PR. The most commonly used conduits are pulmonary and aortic homografts or bovine jugular 
vein grafts (Contegra® Pulmonary Valved Conduit, Medtronic Inc., Minneapolis, Minnesota). Due to time-
dependent conduit deterioration, patients require re-intervention at some point. In the majority of cases, 
this re-valving can be performed percutaneously with a transcatheter valve (Melody® Transcatheter 
Pulmonary Valve, Medtronic Inc., Minneapolis, Minnesota). 
 

 
 
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Follow-up 
 
The use of of paraclinical testing in Tetralogy of Fallot is directed towards assisting with surgical planning 
during the neonatal period and later in life, individualized supportive medical treatment, as well as 
prediction of long-term morbidity and mortality.  
 
Strategies for investigation of anatomy and physiology in patients with congenital heart defects are 
changing rapidly, with a shift from invasive studies to non-invasive protocols involving imaging studies such 
as echocardiography, cardiovascular magnetic resonance imaging (CMR), computed tomography, 
evaulation of arrhythmias using electrocardiograms, Holter-monitoring, event recorders and eventually 
electrophysiology testing as well as cardiopulmonary exercise testing (CPET) which has gained particular 
importance in the longitudinal follow-up and timing of intervention and re-intervention. Due to the ongoing 
improvement of these non-invasive methods, the use of invasive studies, such as cardiac catherization can 
often be reserved for resolution of specific anatomical and physiological qestions, or for intervention. 
 
In adult patients with heart failure but without congenital heart defects, the role of cardiac biomarkers has 
increased exponentially over the last decades, including markers of myocardial injury and stress (e.g. 
cardiac troponins, creatine kinase, B-type natriuretic peptide and the N-terminal segment of pro-B-type 
natriuretic peptide, ST2, serum heart-type fatty-acid binding protein, adrenomedullin, growth 
differentiation factor 15), as well as markers of cardiac remodelling and fibrosis (e.g. connective tissue 
growth factor, type 1 procollagen C-terminal propeptide, carboxy-terminal telopeptide of collagen type I, 
tissue-inhibitor of metalloproteinases-1). The role of these biomarkers is emphasized in the current 
guidelines, as they can reflect important biological processes, but also because these biomarkers open up 
the possibility of possible therapeutic targets.  
 
There is however, a substantial lack of data regarding the validity of biochemical biomarkers in patients 
with congenital heart defects, which is demonstrated by an almost complete abscence of 
recommendations for the utilization of biomarkers in the most recent guidelines for the management of 
grown- up congenital heart disease from the European Society of Cardiology.12  
 
Aims and hypotheses 
 
Even though management and care of CHD has improved, they are still associated with increased long-term 
morbidity, usually requiring life-long follow up and death rates twice to seven times higher compared to 
the general population.13–15  Free PR as a consequence of RVOT repair with a TAP is the most significant 
haemodynamic lesion in patients suffering from sudden cardiac death late after initial repair of ToF.16 
Furthermore, PR is correlated to right ventricular dilatation and dysfunction, exercise intolerance and 
supra-ventricular as well as ventricular arrhythmias. The importance of maintaining a competent 
pulmonary valve has been emphasized, and preservation or reconstruction of pulmonary competence at an 
appropriate point in time has resulted in haemodynamic improvement of patients with PR after repair of 
ToF. However, optimal timing of re-valving in patients with ToF and free PR remains to be established in 
order to avoid irreversible impairment of right ventricular function. Although delayed intervention may 
result in ventricular dysfunction and fibrosis, valve replacement is associated with risks, including 
procedure related complications, altered ventricular geometry, infective endocarditis as well as prosthetic 
valve deterioration and the need for re-intervention.  
 
American, European and Canadian guidelines for re-valving in asymptomatic patients with free PR after 
repair of ToF recommend re-valving when the right ventricle end-diastolic volume index (RVEDVi) has 
nearly doubled (> 160 ml/m2), the exercise capacity declines or when arrhythmias arise (Table 1). 
 

 
 
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Table 1. Summary of published guidelines for surgical pulmonary valve replacement in the asymptomatic patient. 
  
 
It may be argued that these guidelines are too conservative, as more than half of the patients reaching an 
RVEDVi > 160 mL/m2 do not reverse-remodel to normal right ventricular size or recover from reduced right 
ventricular function after re-valving.17,18 Furthermore, pulmonary valve replacement does not have major 
impact on exercise impairment or the risk of ventricular tachycardia, at least when performed in adults with 
ToF and long-standing free PR.19  
 
The current guidelines are based solely on retrospective studies, rather than prospective controlled trials. 
The aims of this study are to evaluate the long-term impact of free PR on right ventricular dimensions, 
function, fibrosis, exercise capacity and arrhythmias, as well as to compare outcomes and safety of an early 
re-valving strategy versus current guideline practice in patients with ToF initially repaired with a TAP. 
 
Based on the abovementioned, our main hypotheses are, that in patients after repair of ToF using a TAP: 
 
1. The duration of PR is correlated with progressive right ventricular dysfunction, dilatation and 
fibrosis, as well as impaired exercise capacity and increased burden of arrhythmias. 
2. The earlier re-valving is performed, the greater is the chance of beneficial reverse remodelling of 
the right ventricle, preservation of exercise capacity and absence of arrhythmia. 
3. Early re-valving is safe with regards to procedural outcome and infective endocarditis (Appendix 1). 
 
Study design 
 
The study will be divided in two sub-studies: 
 
Sub-study I: Cross-sectional evaluation of the impact of long-standing PR after initial repair of ToF 
with pulmonary stenosis.  
 
Sub-study II: Randomized clinical trial comparing an early and later re-valving strategy in patients 
with ToF and free PR after repair with a TAP. 
 
A detailed description of the sub-studies is given in the following sections. 
 
 
 
 

 
 
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Sub-study I: Cross-sectional evaluation of the impact of long-standing PR after initial repair of ToF 
with pulmonary stenosis.  
 
Aims 
 
1. To compare right ventricular dimensions and function, functional class, exercise capacity, presence 
of sustained arrhythmia, biochemical biomarkers of myocardial injury, myocardial stress, 
remodelling and fibrosis as well as other measures at different ages in patients with ToF repaired 
using a TAP compared to patients with ToF who have undergone valve-sparing repair in the Danish 
cohort of patients with ToF. 
1. To evaluate whether the patient age (early: 10-18 years of age, intermediate 19-27 years of age, 
late: > 27 years of age) at re-valving in patients with ToF repaired with a TAP affects right 
ventricular remodelling, functional class, exercise capacity, burden of arrhythmia, biochemical 
biomarkers of myocardial injury, myocardial stress, remodelling and fibrosis, as well as assessment 
of the correlation between biomarkers of fibrosis to fibrosis assessed by CMR. 
2.  and other measures compared with patients repaired with a valve-sparing approach. 
3. To evaluate the safety of re-valving in patients with ToF repaired with a TAP with regards to post-
operative mortality, stroke, acute kidney impairment, endocarditis etc. 
4. To evaluate the durability of the bioprosthetic pulmonary valve using time to re-intervention as 
end-point. Furthermore, to assess whether the patients' age (early: 10-18 years of age, 
intermediate 19-27 years of age, late: > 27 years of age) at the time of re-valving affects the 
durability of the bioprosthesis. 
 
Inclusion criteria 
 
1. ToF with pulmonary stenosis repaired with or without TAP during the first 2 years of life. 
 
Exclusion criteria 
 
1. ToF with pulmonary atresia, ToF with common atrioventricular canal, ToF with absent pulmonary 
valve syndrome, major aortopulmonary collateral arteries and other significant associated 
anomalies. 
2. Palliation with a shunt (Blalock-Taussig or central) at any time. 
3. Co-morbidity preventing exercise testing (e.g. genetics, neuro-cognitive dysfunction, physical 
disability). 
4. Contraindication for CMR (e.g. permanent pacemaker, intra-cardiac defibrillator, intracranial ferro-
magnetic device). 
5. Pregnancy at time of inclusion. 
6. Age < 12 or unable to comply with instructions given during CMR or exercise testing. 
 
Study population 
 
Of the 1.170 living patients with ToF in Denmark 947 patients (81 %) are 12 years of age or older and as 
such potential candidates for the cross-sectional study assuming all other conditions are satisfied. 503 (53 
%) are male and 444 (47 %) are female. Median age is 29 years (range 12-82 years, IQR 21-46 years). 50 % 
of the patients are living in the Capital Region of Denmark and Zealand, 18 % in the Southern Denmark 
Region, 23 % in the Central Region of Denmark and the remaining 9 % are living in the Noth Denmark 
Region. 
 

 
 
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Methods 
 
The following data will be collected:  
 
1. Patient demographics. 
2. Medical history including surgical notes. 
3. Basic assessment in order to rule out significant neuro-cognitive dysfunction, factors limiting the 
ability to perform exercise testing and contra-indications for CMR. 
4. NYHA/functional-class (Appendix 1) and occurrence of arrhythmias assessed during interview. 
5. Health-related quality of life assessed using a generic measure (EQ-5D-3L). The youth version of the 
EQ-5D-3L (EQ-5D-Y) is used for patients aged 12-15 and allows for later mapping onto the 
corresponding adult scale. The generic questionnaires are available in Danish. 
 
The following will be performed and obtained: 
 
1. ECG 
2. Blood samples (Appendix 1) 
3. 24-hour Holter-monitoring 
4. Transthoracic echocardiography (Appendix 1) 
5. Cardiac CMR (Appendix 1) 
6. Cardio-pulmonary exercise testing (Appendix 1) 
 
Statistical considerations 
 
Efficacy 
 
Several small and uncontrolled CMR studies have evaluated the effect of re-valving on right and left 
ventricular dimensions and function in patients with ToF initially repaired with a TAP (Table 2). Little is 
known regarding long-term outcome for these patients compared to patients who have undergone valve-
sparing repair. Therefore, this study is of explorative nature with the purpose to acquire more knowledge 
about the magnitude of these important issues. We expect about half of the patients in the Danish ToF 
cohort who are 12 years of age or older to be included in the study (approximately 500 patients). 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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Table 2. Effects of pulmonary valve replacement on ventricular mechanics, QRS duration, peak oxygen consumption 
and functional class.  
 
 
Adapted from "Repaired Tetralogy of Fallot: The Roles of Cardiovascular Magnetic Resonance in Evaluating Pathophysiology and for 
Pulmonary Valve Replacement Decision Support", Geva, Journal of Cardiovascular Magnetic Resonance, 2011, Volume 13).20  
 
Data analysis 
 
Using propensity score matching for sex and age at follow-up, patients initially repaired with a TAP will be 
compared to patients treated with valve-sparing surgery with regards to: 
 
1. NYHA functional class 
2. Right and left ventricular dimension (RVEDVi, RVESVi, LVEDVi, LVESVi) and function (PR, RVEF, LVEF) 
measured by cardiac CMR 
3. Localized (late myocardial enhancement) and diffuse (increased septal and left ventricular free wall 
extracellular volume) fibrosis measured by cardiac CMR 
4. Peak VO2 and exercise time 
5. Presence or absence of arrhythmia 
6. NT-proBNP, TnT and CK-MB levels 
7. Quality of life 
8. Number of children for female patients 
 
Furthermore, for patients initially repaired with a TAP and later re-valved, the safety of re-valving will be 
evaluated with regards to: 
 
1. Procedural mortality (within 30 days after surgery) 
2. Disabling stroke 
3. Infective endocarditis 
4. Longevity of the right ventricular to pulmonary artery conduit (time to re-intervention) 

 
 
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Sub-study II: Randomized clinical trial comparing an early and later re-valving strategy in patients with 
ToF and free PR after repair with a TAP. 
 
Aims  
 
The primary endpoints for the randomized trial are efficacy and safety of early re-valving, defined as: 
 
2. Primary efficacy endpoint: 
 
RVEDVi is 35 mL/m2 less in the early re-valving group, compared to the later re-valving group 
 
three years after randomization 
 
2.    Primary safety endpoint: 
 
All-cause mortality within three years after randomization is less than 0.6 % in the early 
 
re-valving group 
 
Secondary endpoints in both groups are assessed once every year, for at least ten years after 
randomization, with the exception of procedure related endpoints (1-3), which are only registered 30 days 
after surgery. The secondary endpoints are defined as: 
 
1. Procedure related bleeding categorized as minor, major and life-threatening (BARC) 
3. Procedure related vascular complications categorized as minor and major 
4. Procedure related acute kidney injury categorized as stage one, two and three 
5. Composite rate of all-cause mortality and disabling stroke 
6. Cardiovascular mortality 
7. Disabling stroke or transient ischemic attack 
8. NYHA/functional class (Appendix 1) 
9. Health-related quality of life will be assessed annularly using a generic measure (EQ-5D-3L) and 
temporal developments described. The youth version of the EQ-5D-3L (EQ-5D-Y) is used for 
patients aged 12-15 years and allows for later mapping onto the corresponding adult scale. The 
generic questionnaires are available in Danish. 
10. New sustained supraventricular or ventricular tachyarrhythmia 
11. Exercise capacity measured as peak-VO2 and exercise time (Appendix 1) 
12. Right and left ventricular re-modelling (EDVi, ESVi, EF, myocardial mass) and fibrosis (assessed by 
CMR and analysis of endomyocardial biopsies (Appendix 1)) 
13. Levels of biochemical biomarkers of myocardial injury, myocardial stress, remodelling and fibrosis, 
as well as assessment of the correlation between biomarkers of fibrosis to fibrosis assessed by CMR 
and analysis of endomyocardial biopsies. 
14. Time-related prosthetic valve safety (structural valve deterioration, infective endocarditis, 
prosthetic valve thrombosis) 
15. Number of contacts to the Health System (hospital and general practitioner) 
16. Number of children for female patients 
 
Study population 
 
The study will include Danish patients who give informed consent and fulfill the inclusion and exclusion 
criteria. Patients included in the cross-sectional study, who are interested in participating in the 
randomized study, will be included consecutively if suitability with regards to the inclusion and exclusion 
criteria for the randomized trial is fulfilled. Of the 1.170 living patients with ToF in Denmark, 707 have not 
yet undergone pulmonary valve replacement and are 12 years of age or older. As such 707 Danish patients 

 
 
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with ToF are possible candidates for the randomized clinical trial assuming all other conditions are satisfied. 
360 (51 %) are male and 347 (49 %) are female. Median age is 30 years (range 12-82 years, IQR 20-46 
years). 
 
Inclusion criteria 
 
1. ToF with pulmonary stenosis repaired with a TAP within the first two years of life. 
2. RVOT anatomy is suitable for implantation of an adult sized conduit ( 18 mm homograft or 
Contegra graft) as assessed by CMR. 
 
Exclusion criteria 
 
1. ToF with pulmonary atresia, ToF with common atrioventricular canal, ToF with absent pulmonary 
valve syndrome, major aortopulmonary collateral arteries and other significant associated 
anomalies. 
2. Palliation with a shunt (Blalock-Taussig or central) at any time. 
3. The patient is symptomatic. 
4. Sustained supraventricular or ventricular arrhythmia. 
5. RVEDVi > 140 mL/m2 as assessed by CMR.*  
6. RVESVi > 60 mL/m2 as assessed by CMR. 
7. RVEF < 50 % as assessed by CMR. 
8. Moderate or severe tricuspid regurgitation as assessed by echocardiography or CMR. 
9. Significant residual lesions requiring intervention (e.g. ventricular septal defect, aortic 
regurgitation, branch pulmonary artery stenosis). 
10. Co-morbidity preventing exercise testing (e.g. genetics, neuro-cognitive dysfunction, physical 
disability). 
11. Contraindication for CMR (e.g. permanent pacemaker, intra-cardiac defibrillator, intracranial ferro-
magnetic device). 
12. Pregnancy at time of inclusion. 
13. Age < 12 or unable to comply with instructions given during CMR or exercise testing. 
 
* Patients who have an RVEDVi > 140 mL/m2 will not be included in the randomized trial, as these are 
expected to meet the guideline criteria for re-valving within few years, and thus the effect of early re-
valving is expected to be limited. 
 
Randomization 
 
Participants will be randomized - stratified by gender (female or male) and age (<16 years or 16 years of 
age) - 1:1 to early or later re-valving. The randomization scheme will be unknown to the recruiters. Due to 
the nature of the study, masking after randomization is not possible. Concomitant surgery including 
prophylactic anti-arrhythmic surgery is allowed in both the early and later re-valving groups.  
 
Early re-valving group 
 
Patients will undergo surgical re-valving with an adult sized ( 18 mm) homograft or Contegra graft and 
open endomyocardial biopsy using standard institutional procedures within three months from 
randomization.  
 
 

 
 
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Later re-valving group 
 
Patients will undergo surgical re-valving with an adult sized ( 18 mm) homograft or Contegra graft and 
open endomyocardial biopsy using standard institutional procedures, within three months from the point 
when they meet the current guideline criteria proposed by the European Society of Cardiology: 
 
1. The patient is symptomatic. 
2. RVEDVi > 160 mL/m2 as assessed by CMR (Appendix 1). 
3. Progressive right ventricular dysfunction with an RVEF < 40 % as assessed by CMR. 
4. Moderate or severe tricuspid regurgitation as assessed by echocardiography or CMR. 
5. Decrease in exercise capacity (objective decrease of 30 % in peak VO2 from baseline test at 
randomization). 
6. Sustained supraventricular or ventricular tachyarrhythmia. 
 
Follow-up 
 
All patients included in the randomized trial will be followed for at least ten years after randomization and 
the following examinations will be performed once every year: 
 
1. Assessment of procedure-related complications, cardiovascular events, mortality, number of 
contacts to the health system and number of children for female patients using record data 
2. NYHA/functional-class (Appendix 1) and occurrence of arrhythmias as assessed during interview 
3. ECG 
4. Blood samples (Appendix 1) 
5. 24-hour Holter-monitoring 
6. Transthoracic echocardiography (Appendix 1) 
7. Cardiac CMR (Appendix 1) 
8. Cardio-pulmonary exercise testing (Appendix 1) 
 
Statistical considerations 
 
Efficacy 
 
Several studies report a reduction of 30-40 % in RVEDVi after re-valving (Table 2). We assume that RVEDVi 
will continue to increase over time in the later re-valving group, but not in the early re-valving group.  
 
Statistical power 
 
Based on the reported data, we assume that: 
 
1. At the time of randomization patients have a median RVEDVi of 115 mL/m2. 
2. Three years after randomization, RVEDVi will be reduced by 20 % (from 115 to 92 mL/m2) in the 
early re-valving group. 
3. Three years after randomization, RVEDVi will be increased by 10 % (from 115 to 127 mL/m2) in the 
later re-valving group. 
4. Conservation estimate of the standard deviation of 20 mL/m2. 
5. 120 patients will be included (60 for early and 60 for later re-valving) with an expected loss to 
follow-up of 15 %, thus leaving 102 patients for end-point analyses. 

 
 
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Under these assumptions the study will be adequately powered and have > 90 % power to detect an 
absolute difference in RVEDVi of 35 mL/m2 between the two groups, corresponding to an effect size of 
1.75 expressed as Cohen’s d (Figure 5).  
 
Figure 5. Post Hoc Calculation of the Achieved Power in the Randomized Trial with a Graphical Presentation of the 
Relationship Between Effect Size and Statistical Power Under the Abovementioned Assumptions. 
 
  
 
 
Safety and ethical aspects 
 
As with every type of cardiac surgery early re-valving has potential risks including minor procedure related 
complications such as bleeding, transient cardiac arrhythmia, pneumothorax, pleural effusion, transient 
renal impairment and surgical site infection which occur in about 10 % of patients and which can all be 
treated rather easily. Major procedure related complications include stroke, sternal infection and the risk of 
death, which are all very rare complications. In 16 studies published between 1985 and 2010 including a 
total of 1.035 patients with ToF and free PR, the procedure-related mortality was only 0,68 % (Table 3). The 
most recent studies from 2002-2010 report an operative mortality of 0,4 %, with 10 studies reporting no 
procedure-related mortality at all. 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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Table 3. Operative Mortality After Surgical Pulmonary Valve Replacement.  
 
Adapted from "Repaired Tetralogy of Fallot: The Roles of Cardiovascular Magnetic Resonance in Evaluating Pathophysiology and 
for Pulmonary Valve Replacement Decision Support", Geva, Journal of Cardiovascular Magnetic Resonance, 2011, Volume 13).20 
The overall incidence of sudden cardiac death (SCD) is 0.1-0.2 % annually, with an incremental increase to 4 
% at 25 years and 6 % at 30 years of follow-up, thus suggesting a time-dependent risk of late mortality. In 
the present randomized trial, the incidence of SCD is expected to be 0.2 % per year for the group of 
patients undergoing later re-valving and 0.1 % per year for the group undergoing early re-valving. Assuming 
a perioperative mortality of 0.3 % in the early re-valving group, the cardiac mortality is expected to be 
approximately 0.6 % after three years in both the early and the later re-valving group. Other potential risks 
associated with early re-valving are altered ventricular geometry, infective endocarditis as well as 
prosthetic valve deterioration requiring re-intervention. The incidence of infective endocarditis is reported 
to be very low after surgical pulmonary valve replacement using homograft and Contegra grafts, and 
therefore not expected to be of concern in the early re-valving group. Studies have shown several factors 
affecting the longevity of right-ventricular-to-pulmonary-artery conduits, with smaller conduits being 
particularly prone to deterioration. Thus, patients will only be included in the randomized trial, if CMR and 
echocardiography ensure, that the patient's anatomy allows implantation of an adult sized conduit ( 18 
mm). Most deteriorated conduits can be replaced by percutaneous techniques using transcatheter re-
valving. Re-valving is performed as a routine procedure at Rigshospitalet by experienced cardiothoracic 

 
 
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surgeons and cardiologists, who are certified in the invasive treatment of congenital and structural heart 
abnormalities. Following surgery patients are admitted to the cardiothoracic intensive care unit for one to 
two days, where anaesthesiologists who are also experienced in congenital heart diseases, are focused on 
pain management as well as stabilization of patients, to ensure a safe transition from surgery to 
rehabilitation, starting at the cardiothoracic ward, where patients are discharged after an additional five to 
six days. All staff members involved in these processes are skilled in paediatric care and communication. 
In conclusion, the risk of early re-valving is considered very low and to outweigh the potential adversities of 
later re-valving, which is associated with irreversible right ventricular dysfunction, exercise impairment, 
arrhythmia and SCD. Furthermore, the study has to include children in the specified age range (12 years of 
age or older) with Tetralogy of Fallot, as the potential benefits of the treatment sought to be evaluated 
cannot be extrapolated from older patients in whom the right ventricle is already irreversibly impaired due 
to the consequences of free/severe PR. 
 
Time schedule, study organization, research staff, participant recruitment and PhD studies 
 
Time schedule 
 
The study is planned to start in April 2019 and the last patient in the randomized clinical trial to pass the 10-
year follow-up by December 2031 (Figure 6). 
 
Figure 6. Expected time frame for the study. 
 
 
 
Study organization 
 
Follow-up of complex congenital heart diseases in Denmark is centralized at Rigshospitalet, Odense 
University Hospital and Aarhus University Hospital Skejby and the study will be a close collaboration 
between these three centres. The study organization will include paediatric cardiologists and adult 
cardiologists from the three involved centres, and cardiac surgeons from Rigshospitalet who are specialized 
in congenital heart diseases. Physicians in the study organization will participate in the recruitment, 
treatment and follow-up of the study patients. Furthermore, public involvement is important in order to 
ensure that the study design, conduction and evaluation meet the users' perspectives. Therefore, one 

 
 
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patient and one patient relative will be involved in these processes as members of the study organization. 
Particular contributions from the two members include evaluation of whether exercise tolerance, quality of 
life, absence from education/work, number of contacts to the health care system (hospital and general 
practitioner) and counselling regarding pregnancy will be different in the two groups. Due to practical 
issues the study will be coordinated from the Department of Cardiology, Rigshospitalet in Copenhagen, 
where the principal investigators Lars Søndergaard and Morten Smerup as well as the PhD students and 
study nurse will be based. 
 
Rigshospitalet, Copenhagen 
Henrik Ørbæk Andersen, cardiac surgeon 
Morten Helvind, cardiac surgeon 
Morten Holdgaard Smerup, cardiac surgeon 
Klaus Juul, paediatric cardiologist 
Lars Søndergaard, adult cardiologist 
 
Odense University Hospital 
Helle Andersen, paediatric cardiologist 
Henrik Nissen, adult cardiologist 
 
Aarhus University Hospital Skejby 
Dorte Guldbrand Nielsen, adult cardiologist 
Kim Munk, adult cardiologist 
 
Public involvement 
Relative - mother of two children with ToF 
Patient - patient with ToF repaired with a TAP and later re-valved. 
 
Research staff 
 
In addition to the study group, one study nurse and two PhD students (with different starting points due to 
the time frame of the study) will be involved and based at Rigshospitalet, as well as one part time study 
nurse at Odense University Hospital and Aarhus University Hospital. Mathis Gröning, MD, is expected to 
start in as the first PhD student in April 2019. The study nurses and the PhD students will coordinate the 
work, participate and supervise parts of the examinations and ensure proper data collection at all three 
study sites. Furthermore, they will continuously update the study organization regarding the study progress 
and potential issues. 
 
Participant recruitment 
 
As soon as the study is approved by the Danish Ethics Committee, all Danish patients with ToF will be 
identified through the Danish National Patient Registry. Data extracted from the registry will be civil names 
and addresses. In patients under the age of 18 years, the names and addresses of patients' parents or legal 
guardians will be extracted as well. Letters containing information about the study, consent forms and 
medical power of attorney forms are sent to all patients or patients' parents in patients under the age of 18 
years. Patients who are interested in participating are encouraged to contact the study group as stated in 
the information letter, in order to set up an appointment at the nearest hospital. The PhD student will 
inform patients about the studies in Copenhagen, whereas this task will be taken care of by the recruiting 
physicians in Odense and Aarhus. An appropriate amount of time will be scheduled for every appointment, 
in order to make sure, that all possible questions can be clarified before consent forms are signed. 
Information will be presented in an easily understandable manner, especially if the patient is a child and be 

 
 
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based on the written information in the information letter including information about risks, complications, 
handling of personal data. All recruiters are skilled in communication with the paediatric population and 
have detailed knowledge about the study and congenital heart diseases in general. Patients who need 
further time for consideration are offered at least 24 hours to make up their minds, and are encouraged to 
contact one of the recruiting physicians, the PhD student or the study nurse when a conclusion is reached, 
in order to set up a new appointment, where consent forms can be signed. In patients who are not of legal 
age (under 18 years of age) consent from is needed from every person who has custody of the child. New 
consent will be achieved for enrolled patients who reach legal age during their participation in the study. 
Whether or not patients want to receive information regarding their health status acquired through 
examinations conducted as part of the study is optional. Patients will be informed if novel knowledge 
regarding risks and complications associated with their participation in the study is achieved during the 
study period, as well as if the design of the study is changed at any point, or if the information achieved 
during the study changes recommendations with regards to the most appropriate treatment of the 
individual patient, provided patients did not decide to stay uninformed in these cases. In case of 
discontinuation of the study enrolled patients will be informed about the reason for this decision.  
 
PhD studies 
 
There will be two PhD studies attached to the project (PhD 1: January 2019 - December 2021; PhD 2: July 
2021 - June 2014). The time frames of the students' employment will include six months of overlay, in order 
to secure a smooth hand-over of the project from the first to the second PhD student, as well as to ensure 
sufficient time for the first student to finish the thesis. 
 
PhD 1 will focus on the data from the cross-sectional study (sub-study 1). This may include, but not be 
limited to: 
 
1. To compare right ventricular dimensions and function, functional class, exercise capacity, presence 
of sustained arrhythmia, biochemical biomarkers of myocardial injury, myocardial stress, 
remodelling and fibrosis as well as other measures at different ages in patients with ToF repaired 
using a TAP compared to patients with ToF who have undergone valve-sparing repair in the Danish 
cohort of patients with ToF. 
2. To evaluate whether the patient age (early: 10-18 years of age, intermediate 19-27 years of age, 
late: > 27 years of age) at re-valving in patients with ToF repaired with a TAP affects right 
ventricular remodelling, functional class, exercise capacity, burden of arrhythmia, biochemical 
biomarkers of myocardial injury, myocardial stress, remodelling and fibrosis and other measures 
compared with patients repaired with a valve-sparing approach. 
3. To evaluate the safety of re-valving in patients with ToF repaired with a TAP with regards to post-
operative mortality, stroke, acute kidney impairment, endocarditis etc. 
4. To evaluate the durability of the bioprosthetic pulmonary valve using time to re-intervention as 
end-point. Furthermore, to assess whether the patients' age (early: 10-18 years of age, 
intermediate 19-27 years of age, late: > 27 years of age) at the time of re-valving affects the 
durability of the bioprosthesis. 
 
PhD 2 will focus on the outcome of the randomized clinical trial (sub-study 2). This may include, but not 
limited to: 
 
1. Primary efficacy endpoint: RVEDVi is 35 mL/m2 less in the early re-valving group, compared to the 
later re-valving group three years after randomization 
2. Primary safety endpoint: All-cause mortality within three years after randomization is less than 0.6 
% in the early re-valving group 

 
 
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3. Procedure related bleeding categorized as minor, major and life-threatening (BARC) 
4. Procedure related vascular complications categorized as minor and major 
5. Procedure related acute kidney injury categorized as stage one, two and three 
6. Composite rate of all-cause mortality and disabling stroke 
7. Cardiovascular mortality 
8. Disabling stroke or transient ischemic attack 
9. NYHA/functional class (Appendix 1) 
10. Health-related quality of life using a generic measure (EQ-5D-3L) will be assessed annularly and 
temporal developments described. The youth version of the EQ-5D-3L (EQ-5D-Y) is used for 
patients aged 12-15 years and allows for later mapping onto the corresponding adult scale. The 
generic questionnaires are available in Danish. 
11. New sustained supraventricular or ventricular tachyarrhythmia 
12. Exercise capacity measured as peak-VO2 and exercise time (Appendix 1) 
13. Right and left ventricular re-modelling (EDVi, ESVi, EF, myocardial mass) and fibrosis (assessed by 
CMR and analysis of endomyocardial biopsies (Appendix)) 
14. Time-related prosthetic valve safety (structural valve deterioration, infective endocarditis, 
prosthetic valve thrombosis) 
15. Number of contacts to the Health System (hospital and general practitioner) 
16. Number of children for female patient 
 
Permissions, equipment, reimbursement, budget and funding 
 
Permissions 
 
The 4th version of the study protocol has been approved by the Danish Ethical Committee and the Danish 
Data Protection Agency. The Danish Ethical Comittee and the Danish Data protection agency are applied for 
approval of the 5th version of the study protocol. Important amendments in the 5th version include 
sections regarding laboratory tests, endomyocardial biopsies, the establishment of a biobank as well as an 
update of the budget and funding sections. 
 
Equipment 
 
Echocardiographic systems, CMR scanners and ECG machines will be available at all three participating 
hospitals. Expenses for equipment for cardio-pulmonary exercise testing and Holter monitoring will partly 
be covered by the study and located at Rigshospitalet, Odense University Hospital, and Aarhus University 
Hospital. Expenses for paraclinical tests will be considered as standard of care.  
 
Reimbursement 
 
Additional travel expenses arising due to appointments in addition to regular clinical follow-up at the 
hospital during the study period will be reimbursed. In total, 120 patients in the randomized trial are 
expected to have 1.200 additional travels.  
 
Budget 
 
2 PhD students 
(2 x 3 years) x 600.00 DKK/year 
3.600.000 DKK 
1 full-time study nurse 
10 years x 460.000 DKK/year  
4.600.000 DKK 
2 part-time study nurses 
10 years x 230.000 DKK/year  
2.300.000 DKK 
Travel expenses staff 
10 years x 25.000/year 
 
    450.000 DKK 

 
 
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Travel expenses patients 
1.200 travels x 500 DKK 
 
    500.000 DKK 
Exercise equipment 
1 x 200.000 DKK 
 
    200.000 DKK 
________________________________________________________________________ 
Total expenses 
   
 
 
11.200.000 DKK 
 
 
Funding 
 
5.000.000 DKK have been granted by the Danish Heart Foundation and 5.055.000 DKK have been granted 
by the Novo Nordisk Foundation. The remaining amount will be applied for at a later stage. The Danish 
Ethical Committee as well as patients enrolled in the study will be informed if other funding is achieved. 
Grants will be administered by the accounting service of Rigshospitalet, Copenhagen.  
 
Implementation 
 
Optimal timing of re-valving in patient with ToF and free PR is unknown. Although treatment according to 
the current guidelines results in good short and intermediate term outcomes, there are major concerns 
regarding the long-term perspective for the commonly applied re-valving strategy. This includes the lack of 
full remodelling of the right ventricle, permanent impairment of exercise capacity, arrhythmia and the risk 
of sudden cardiac death. Robust data and randomized trials in particular are needed. This study addresses 
these issues and the outcomes may have an impact on clinical practice and guidelines regarding the optimal 
timing of re-valving in a national as well as international scale. The study results will be published in 
international peer-reviewed journal in order to ensure dissemination of the acquired knowledge. 
 
Summary 
 
About 25 children are born with Tetralogy of Fallot in Denmark every year. Due to improvements in 
diagnosis, management and care most of these children now reach adulthood. Despite an excellent 
outcome, the long-term mortality rate is still increased compared to the general population. Free 
pulmonary regurgitation as a consequence of right ventricular outflow tract repair with a transannular 
patch, is the main reason for higher mortality rates, as long-standing severe pulmonary regurgitation is 
associated with chronic volume overload on the right ventricle leading to right ventricular dysfunction, 
impaired exercise capacity, arrhythmia and increased risk of sudden cardiac death. Current guidelines for 
re-valving are based solely on retrospective studies, and as such, optimal timing remains controversial. The 
current recommendations suggest re-valving when right ventricular size has almost doubled or when 
symptoms arise. However, after this conservative approach to re-valving patients do not experience 
significant improvement in exercise capacity or burden of arrhythmia, and in the majority of cases the right 
ventricle does not reverse remodel to normal size. As operative mortality for surgical pulmonary valve 
replacement is very low, a more favourable approach might be to strive for implantation of a valved 
conduit as soon as the child's anatomy allows for the use of an adult-sized prosthesis, which has an 
increased longevity compared to smaller conduits. 
The aim of this study is to evaluate the benefits and drawbacks of an early versus later approach to re-
valving and it will be divided in two sub-studies. The first part will be a cross-sectional evaluation of 
approximately 500 Danish patients with Tetralogy of Fallot, with tests including echocardiography, cardiac 
MRI, Holter-monitoring, exercise testing and blood samples. The study will provide information about the 
long-term outcomes after initial repair of Tetralogy of Fallot, as well as suggestions about the optimal 
timing for re-valving. Among patients included in the cross-sectional study, 120 patients with free 
pulmonary regurgitation, will be randomized evenly for early or later re-valving with at least 10-years of 
follow-up, in order to evaluate long-term efficacy and safety of early re-valving. Novel insights regarding 
the optimal timing of re-valving in patients with Tetralogy of Fallot and pulmonary regurgitation after initial 

 
 
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repair with a transannular patch will be achieved. If this study can prove, that early re-valving is more 
advantageous than the current approach, it can contribute to a change of recommendations in favour of 
early re-valving on an international scale. 
 
Conflicts of interest 
None of the staff members has any affiliation to the grant givers or other financial interests in the 
conduction of the study. 
 
References 
 
1.  
Bernier PL, Stefanescu A, Samoukovic G, Tchervenkov CI. The challenge of congenital heart disease 
worldwide: Epidemiologic and demographic facts. Semin Thorac Cardiovasc Surg Pediatr Card Surg 
Annu. 2010;13(1):26-34. doi:10.1053/j.pcsu.2010.02.005. 
2.  
Calzolari E, Barisic I, Loane M, et al. Epidemiology of multiple congenital anomalies in Europe: A 
EUROCAT population-based registry study. Birth Defects Res Part A - Clin Mol Teratol. 
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Dolk H, Loane M, Garne E. Congenital heart defects in Europe: Prevalence and perinatal mortality, 
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Van Der Linde D, Konings EEM, Slager MA, et al. Birth prevalence of congenital heart disease 
worldwide: A systematic review and meta-analysis. J Am Coll Cardiol. 2011;58(21):2241-2247. 
doi:10.1016/j.jacc.2011.08.025. 
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Bhatt AB, Foster E, Kuehl K, et al. Congenital Heart Disease in the Older Adult: A Scientific Statement 
From the American Heart Association. Vol 131.; 2015. doi:10.1161/CIR.0000000000000204. 
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Warnes CA, Liberthson R, Danielson GK, et al. Task Force 1: the changing profile of congenital heart 
disease in adult life. J Am Coll Cardiol. 2001;37(5):1170-1175. doi:10.1016/S0735-1097(01)01272-4. 
7.  
Baird PA, Sadovnick AD, Yee IML. Maternal age and birth defects: a population study. Lancet. 
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8.  
Van Der Bom T, Zomer AC, Zwinderman AH, Meijboom FJ, Bouma BJ, Mulder BJM. The changing 
epidemiology of congenital heart disease. Nat Rev Cardiol. 2011;8(1):50-60. 
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9.  
Donofrio MT, Moon-Grady AJ, Hornberger LK, et al. Diagnosis and treatment of fetal cardiac disease: 
A scientific statement from the american heart association. Circulation. 2014;129(21):2183-2242. 
doi:10.1161/01.cir.0000437597.44550.5d. 
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Al Habib HF, Jacobs JP, Mavroudis C, et al. Contemporary patterns of management of tetralogy of 
fallot: Data from the society of thoracic surgeons database. Ann Thorac Surg. 2010;90(3):813-819. 
doi:10.1016/j.athoracsur.2010.03.110. 
11.  
Sen DG, Najjar M, Yimaz B, et al. Aiming to Preserve Pulmonary Valve Function in Tetralogy of Fallot 
Repair: Comparing a New Approach to Traditional Management. Pediatr Cardiol. 2016;37(5):818-
825. doi:10.1007/s00246-016-1355-1. 
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Tornos P, Brecker S, Dean V, et al. ESC Guidelines for the management of grown-up congenital heart 
disease (new version 2010): The Task Force on the Management of Grown-up Congenital Heart 
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doi:10.1093/eurheartj/ehq249. 
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Videbæk J, Laursen HB, Olsen M, Høfsten DE, Johnsen SP. Long-term nationwide follow-up study of 
simple congenital heart disease diagnosed in otherwise healthy children. Circulation. 
2016;133(5):474-483. doi:10.1161/CIRCULATIONAHA.115.017226. 
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Marelli AJ, Ionescu-Ittu R, Mackie AS, Guo L, Dendukuri N, Kaouache M. Lifetime prevalence of 
congenital heart disease in the general population from 2000 to 2010. Circulation. 2014;130(9):749-
756. doi:10.1161/CIRCULATIONAHA.113.008396. 

 
 
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15.  
Verheugt CL, Uiterwaal CSPM, Van Der Velde ET, et al. Mortality in adult congenital heart disease. 
Eur Heart J. 2010;31(10):1220-1229. doi:10.1093/eurheartj/ehq032. 
16.  
Gatzoulis M a, Balaji S, Webber S a, et al. Risk factors for arrhythmia and sudden cardiac death late 
after repair of tetralogy of Fallot: a multicentre study. Lancet. 2000;356(9234):975-981. 
doi:10.1016/S0140-6736(00)02714-8. 
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Therrien J, Siu SC, McLaughlin PR, Liu PP, Williams WG, Webb GD. Pulmonary valve replacement in 
adults late after repair of tetralogy of Fallot: Are we operating too late? J Am Coll Cardiol. 
2000;36(5):1670-1675. doi:10.1016/S0735-1097(00)00930-X. 
18.  
Therrien J, Provost Y, Merchant N, Williams W, Colman J, Webb G. Optimal timing for pulmonary 
valve replacement in adults after tetralogy of Fallot repair. Am J Cardiol. 2005;95(6):779-782. 
doi:10.1016/j.amjcard.2004.11.037. 
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Legendre A, Richard R, Pontnau F, et al. Usefulness of maximal oxygen pulse in timing of pulmonary 
valve replacement in patients with isolated pulmonary regurgitation. Cardiol Young. 2015;(2016):1-
9. doi:10.1017/S1047951115002504. 
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Geva T. Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating 
pathophysiology and for pulmonary valve replacement decision support. J Cardiovasc Magn Reson. 
2011;13(1):9. doi:10.1186/1532-429X-13-9. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
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Appendix 1 
 
NYHA functional class assessment 
 
It is well described, that patients with congenital heart diseases adapt their physical activities to their 
condition and thus underreport symptoms. A specific activity is used in this study, to allow for a more 
objective assessment of patients' functional class (figure 6). 
 
 
Figure 6. Specific Acitivity Scale Which Will Be Used for Assessment of Patients' Functional Class During Interviews. 
Modified from "Comparative Reproducibility and Validity of Systems for Assessing Cardiovascular Functional Class: Advantages of a 
New Specific Activity Scale", Goldman et al., Circulation, 1981, Volume 64, page 1227.21 
 
 
 
ECG 
 
A standard 12-lead surface ECG is obtained for assessment of: 
 
▪ 
Heart rhythm 
▪ 
Ventricular rate 
▪ 
Intervals 
▪ 
Conduction disturbances 
▪ 
Ischemia 

 
 
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Echocardiography 
 
In addition to CMR TTE is performed in all patients for assessment of valvar regurgitation and pressure 
gradients, as well as residual defects using the following protocol: 
 
All B-mode loops will include a minimum of 2 beats. All Spectral Doppler traces are optimized with sweep 
setting allowing 3 beats.  
 
• 
Subxiphoid: optimized for IVC with and without inspiration 
• 
PLAX: RV linear dimension, LV linear dimension 
• 
PLAX color: MV and AV interrogation of valve regurgitation 
• 
SAX RVOT level: Color interrogation of RVOT, PW spectral Doppler below PV/conduit for PA 
acceleration time, CW Doppler optimized for MPA antegrade flow velocity, CW Doppler optimized 
for RVOT regurgitant flow profile. PW interrogation of LPA and RPA 
• 
4C: LV and RV dimensions and function, 4C loop optimized for GLS calculation,  
• 
4C color: MV interrogation for MI estimation 
• 
2C: LV dimension and function, 2C loops optimized for GLS calculation 
• 
2C color: MV interrogation for MI estimation 
• 
APLAX: LV dimension and function, APLAX loops optimized for GLS calculation 
• 
APLAX color: MV and AV interrogation for MI and AI/AS estimation 
• 
4C RV optimized for free wall and septal GLS calculation 
 
Cardiovascular magnetic resonance (CMR) imaging  
 
CMR is performed for assessment of: 
 
1. Ventricular size and function 
2. Characterization of pulmonary outflow at three levels 
3. Right and left ventricular scar tissue and localized fibrosis 
4. Quantification of right and left ventricular diffuse fibrosis 
 
Ventricular size and function 
 
Right ventricular end systolic and end diastolic volumes are measured from a transverse stack of images 
without gaps using steady-state free precession cine sequences. Left ventricular volumes are measured 
using a short axis stack through the left ventricle. The following measurements will be obtained: 
 
▪ 
Right ventricular end-systolic and end-diastolic volume index (RVESVi and RVEDVi) 
▪ 
Right ventricular ejection fraction (RVEF) 
▪ 
Left ventricular end-systolic and end-diastolic volume index (LVESVi and LVEDVi) 
▪ 
Left ventricular ejection fraction (LVEF) 
▪ 
Septal and left ventricular free wall extracellular volume 
 
Characterization of pulmonary outflow at three levels 
 
Pulmonary blood flow is measured as forward flow, regurgitant volume and fraction. Velocity encoding is 
performed in the main pulmonary artery. 

 
 
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Right and left ventricular scar tissue and localized fibrosis 
 
A 3D whole heart, inversion-recovery gradient echo pulse sequence with a respiratory navigator pulse 
placed over the dome of the right hemidiaphragm is used to obtain both an early (coronary enhanced) and 
late (scar enhanced) dataset (voxel size 1.3 x 1.3 x 1.3 mm3 with interpolation to 0.65 mm for 
reconstruction, echo time 1.3 ms, flip angle 20 degrees, integrated parallel acquisition technique 2, end-
expiratory respiratory navigator acceptance window 3.5 mm, phase encoding direction anterior-posterior). 
Fat saturation is employed to supress pericardial fat signal. Imaging volumes are prescribed in the 
transverse plane from the aortic arch to below the most inferior aspect of the heart (slab thickness 120-144 
slices) based on multiplanar scout images. Adjustment of trigger delay and number of segments is 
performed to maintain image acquisition between the onset and termination of cardiac standstill and 
determined from the 4-chamber cine.  
 
For coronary-enhanced imaging, an intravenous infusion of gadolinium contrast (0.15 mmol/kg) is infused. 
Imaging is initiated 25 seconds following infusion onset. A repeat scar-enhanced dataset is acquired 20-25 
minutes after infusion onset with adjustment of the inversion time to provide optimal myocardial signal 
suppression. The inversion-time is set at 200 ms for scar-enhanced imaging (typical range 240-270 ms). 
These adjustments are performed using a test-image slab (10 mm thickness) acquired over the mid-
ventricle. The acceptance rate of the respiratory navigator is recorded for both full-volume acquisitions.  
 
Feasibility, accuracy and reproducibility of the abovementioned methods for assessment of ventricular scar 
tissue and localized fibrosis have been demonstrated by other researchers.2  
 
Quantification of right and left ventricular diffuse fibrosis 
 
Equilibrium contrast cardiovascular magnetic resonance (CMR) is used in this setting. T1 mapping is 
performed in three short axis slices through the heart with modified Look-Locker inversion recovery 
(MOLLI) sequences. Nine minutes after infusion of gadolinium contrast T1 mapping is repeated in the same 
3 slices. Using the patient's haematocrit, the extracellular volume (ECV) in the interventricular septum and 
left ventricular free wall is calculated using the following equation: 
 
ECV = (1-haematocrit) x (1/T1myocardium post-contrast - 1/T1myocardium pre-contrast)/1/T1blood post-contrast - 1/T1blood pre-contrast) 
 
As the right ventricular free wall is thin and trabeculated, it is not suited for T1 mapping. 
 
Post-processing 
 
Imaging is performed using a 1.5 Tesla Siemens scanner. Post-processing of the MRI measurements is 
performed using CVI42 (Circle of Cardiovascular Imaging, Calgary, Canada) on Macintosh computers (Apple 
Inc., Cupertino, USA). 
 
Safety 
 
Pregnancy will be ruled out for all female patients of childbearing age, prior to infusion of gadolinium 
contrast and CMR, using a urine pregnancy test.  
 
 
 
 

 
 
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Exercise testing 
 
Cardio-pulmonary exercise testing (CPET) will be performed on a bicycle ergometer. Each test starts with a 
two-minute warm-up. With the aim of reaching maximal effort within 6-12 minutes after the warm-up, an 
appropriate incremental load protocol starting at either 20 W with a stepwise increase of 20 W per minute, 
or starting at 25 W with an increase of 25 W per minute will be chosen for each participant, based on 
expected fitness. Both CPET at baseline and CPET during follow-up will be performed after the same 
protocol. ECG and oxygen saturation will be measured continuously during the test. Respiratory volumes as 
well as O2 and CO2 concentrations will be measured breath by breath through a mask and a connecting 
tube, worn by the patient. Every patient is encouraged to continue the exercise until exhaustion. A 
respiratory exchange ratio > 1.1 will be considered as an indicator of exhaustion. Measurements will be 
given as mean of 15 second intervals, by subtraction of the highest from the lowest value. Peak-VO2 will be 
defined as the 15 second interval with the highest VO2. The anaerobic threshold will be defined as the first 
15-second interval during which the respiratory exchange ratio exceeds 1.0 without a subsequent reduction 
< 1.0. The maximum work-load will be defined as the highest watt load achieved and held for at least 15 
seconds.  
 
Laboratory tests 
 
Laboratory tests are obtained from all patients included in sub-study I (the cross-sectional study) and sub-
study II (the randomized clinical trial).  
 
Sub-study I 
 
 
One set of laboratory tests are obtained from all 500 patients including: 
 
B-haemoglobin, B-erythrocyte count, B-mean corpuscular volume, B-mean corpuscular haemoglobin 
concentration, B-reticulocyte count, B-haematocrit, B-leukocyte count with differential counts (B-
neutrophils, B-eosinophils, B-basophils, B-lymphocytes, B-monocytes), B-platelet count, P-ferritin, P-CRP, P-
albumin, P-potassium, P-sodium, P-creatinine, eGFR*, P, P-aPTT, P-prothrombin time, P-international 
normalized ratio, P-alanine transaminase, P-alkaline phosphatase, P-bilirubin, P-lactate dehydrogenase, P-
glucose, P-haemoglobin A1C, P-cholesterol (total, HDL, LDL, VLDL), P-triglycerides, P-creatine kinase, P-
creatine kinase MB, P-troponin T, P-NT-proBNP and blood samples for storage in a biobank** (3.5 mL in a 
sodium-citrate tube, 12 mL in an EDTA tube and 4 mL in a serum tube with no anticoagulant). 
 
*eGFR is calculated using the CKD-EPI equation. 
** Will only be obtained from patients scheduled for visits at Rigshospitalet, Copenhagen. 
 
Sub-study II 
 
The same laboratory tests obtained as part of sub-study I are obtained at the 10 annual follow-up visits for 
the 120 patients included in substudy II apart from whole blood which is only obtained as part of substudy 
I.  
 
Furthermore, laboratory tests are obtained before surgical revalving as well as 6, 12 and 24 hours after the 
surgical procedure. 80 patients are expected to undergo revalving during the study period (60 early 
revalving procedures and 20 later revalving procedures). 
 
 
Laboratory tests obtained before surgery include: 
 

 
 
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29
B-haemoglobin, B-erythrocyte count, B-mean corpuscular volume, B-mean corpuscular haemoglobin 
concentration, B-reticulocyte count, B-haematocrit, B-leukocyte count with differential counts (B-
neutrophils, B-eosinophils, B-basophils, B-lymphocytes, B-monocytes), B-platelet count, P-ferritin, P-CRP, P-
albumin, P-potassium, P-sodium, P-creatinine, eGFR*, P-aPTT, P-prothrombin time, P-international 
normalized ratio, P-alanine transaminase, P-amylase, P-alkaline phosphatase, P-bilirubin, P-lactate 
dehydrogenase, P-glucose, P-creatine kinase, P-creatine kinase MB, P-troponin T, P-NT-proBNP and blood 
samples for storage in a biobank (3.5 mL in a sodium-citrate tube, 4 mL in an EDTA tube and 4 mL in a 
serum tube with no anticoagulant). 
 
 
Laboratory tests obtained 6, 12 and 24 hours after surgery include: 
 
B-haemoglobin, B-erythrocyte count, B-mean corpuscular volume, B-mean corpuscular haemoglobin 
concentration, B-reticulocyte count, B-haematocrit, B-leukocyte count with differential counts (B-
neutrophils, B-eosinophils, B-basophils, B-lymphocytes, B-monocytes), B-platelet count, P-CRP, P-
potassium, P-sodium, P-creatinine, eGFR*, P-aPTT, P-prothrombin time, P-international normalized ratio, P-
alanine transaminase, P-creatine kinase, P-creatine kinase MB, P-troponin T, P-NT-proBNP and blood 
samples for storage in a biobank (3.5 mL in a sodium-citrate tube, 6 mL in an EDTA tube and 4 mL in a 
serum tube with no anticoagulant). 
 
*eGFR is calculated using the CKD-EPI equation. 
 
Postprocessing of blood samples for biobank storage 
 
Centrifugation of the 3.5 mL of blood in a sodium-citrate tube is performed for 10 minutes at a speed of 
2200 G and a temperature of 20-24 degrees Celsius. The plasma is dispensed into 4 pieces of 2 mL 
cryotubes and frozen for storage in the biobank. 
 
Centrifugation of the 6 mL of blood in an EDTA tube is performed for 10 minutes at a speed of 2200 G and a 
temperature of 20-24 degrees Celsius. The plasma is dispensed into 4 pieces of 2 mL cryotubes and frozen 
for storage in the biobank. The remaining 6 mL of blood in EDTA will be stored as whole blood (only as part 
of sub-study 1 and only for patients scheduled for visits at Rigshospitalet, Copenhagen). 
 
Centrifugation of the 4 mL of blood in a serum tube is performed for 10 minutes at a speed of 2200 G and a 
temperature of 20-24 degrees Celsius. The serum is dispensed into 4 pieces of 2 mL cryotubes and frozen 
for storage in the biobank. 
 
Utilization of blood samples stored in the biobank 
 
Blood samples stored in the biobank will be used for later analysis of biochemical biomarkers of myocardial 
injury, myocardial stress, remodelling and fibrosis.  Furthermore, excess material will be stored in the 
biobank for future, yet undefined research (The Danish Data Protection Agency will be applied for approval 
of this biobank for future, yet undefined research). If further analysis of the extra material is planned at a 
later stage, the Ethics Committee will be applied for approval of this new project and new written consent 
will be obtained from the patients, unless a waiver of consent is considered appropriate by the Ethics 
Committee depending on the circumstances of this new project. Patients will be informed that analysis 
performed at a later stage might include genetic research. 
 
 
 
 

 
 
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30
Endomyocardial biopsies 
 
5 endomyocardial fragments, each 1-2 mm3 in size, are obtained from the right ventricular inlet portion, 
the right ventricular outflow tract and the left ventricular lateral wall during surgical revalving, resulting in a 
total of 15 specimens. Much of the specimens can be obtained from tissue, which is resected as part of the 
revalving procedure in any case, irrespective of the desire to obtain biopsies. 
 
Storage and processing of endomyocardial biopsies 
 
The specimens are stored, processed and evaulated as follows: 
 
9 specimens (three from each biopsy site) are fixed in 10 % buffered formalin and stored at room 
temperature for staining and light microscopy. A haematoxylin and eosin stain is applied to each of these 
specimens at 2 levels of the biopsy. A Masson trichrome collagen stain is applied to each specimen in order 
to determine the degree of endomyocardial fibrosis, a Verhoeff-Van Gieson stain is applied to each 
specimen for evaluation of endomyocardial fibroelastosis and a phosphotungstic acid haematoxylin stain is 
applied to each specimen for identification of myocyte disarray.  
 
3 specimens (one from each biopsy site) are placed in glutaraldehyde fixative for electron microscopy.  
 
3 specimens (one from each biopsy site) are immediately snap frozen in liquid nitrogen and stored at minus 
80 degrees Celsius for later molecular tests and stains. 
 
Techniques used for preparation and processing of the endomyocardial biopsies are in line with the 
consensus statement on endomyocardial biopsy from the Association for European Cardiovascular 
Pathology and the Society for Cardiovascular Pathology and the recommendations for processing 
cardiovascular surgical pathology specimen from the Standards and Definitions Committee of the Society 
for Cardiovascular Pathology and the Association for European Cardiovascular Pathology.22,23 
 
Utilization of endomyocardial biopsies stored in the biobank 
 
Endomyocardial biopsies stored in the biobank will be used for later analysis of myocardial injury, 
myocardial stress, remodelling and fibrosis. Furthermore, excess material will be stored in the biobank for 
future, yet undefined research (The Danish Data Protection Agency will be applied for approval of this 
biobank for future, yet undefined research). If further analysis of the extra material is planned at a later 
stage, the Ethics Committee will be applied for approval of this new project and new written consent will 
be obtained from the patients, unless a waiver of consent is considered appropriate by the Ethics 
Committee depending on the circumstances of this new project. Patients will be informed that analysis 
performed at a later stage might include genetic research. 
 
Safety 
 
Endomyocardial biopsy is a commonly performed procedure for the evaluation of cardiac tissue for 
transplant monitoring, myocarditis, drug toxicity, cardiomyopathy, arrhythmia, secondary cardiac 
involvement in systemic diseases and for the diagnosis of cardiac masses. Endomyocardial biopsies are 
usually obtained percutaneously. As such, data regarding the risks accompanying open chest 
endomyocardial biopsy is limited. Percutaneous endomyocardial biopsy is generally considered a safe 
procedure. Possible complications of percutaneous endomyocardial biopsy include bleeding or hematoma 
at the access sites, arteriovenous fistula, vasovagal reactions, pneumothorax, arrhythmia or conduction 
disturbances, pulmonary embolism during right ventricular biopsy or systemic embolism during left 

 
 
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31
ventricular biopsy and cardiac chamber perforation with possible haemopericardium and cardiac 
tamponade. The overall complication rate of percutaneous endomyocardial biopsy using a flouroscopy or 
ultrasound guided transvenous or transarterial sheath with insertion of a biotome is reported to be 1-2 %. 
In particular the risk of cardiac peforation was estimated to be 0.4 % in the largest case records in the world 
published in 1980 and 0.12 % in a more recent report based on a large number of cases. (reference, 24). The 
risk of complications related to endomyocadial biopsy during open heart surgery is likely to be considerably 
lower, as catheter-related adverse events are precluded (bleeding or hematoma at the access sites, 
arteriovenous fistula, vasovagal reactions, pneumothorax and pulmonary or systemic embolism) and as 
visual instead of flouroscopy or ultrasound guidance of the biotome reduces the risk of cardiac chamber 
perforation and associated complications (haemopericardium and cardiac tamponade).