Pulmonary valve replacement after repair of tetralogy of Fallot: Evolving strategies

Pulmonary valve replacement in tetralogy of Fallot - who and how?

BACKGROUND AND AIM

Pulmonary regurgitation is the most common complication in repaired tetralogy of Fallot patients. Severe chronic pulmonary regurgitation can be tolerated for decades, but if not treated, it can progress to symptomatic, irreversible right ventricular dilatation and dysfunction. We investigated clinical associations with pulmonary valve replacement among patients with significative pulmonary regurgitation and how interventional developments can change their management.

METHODS

All adult patients with repaired tetralogy of Fallot who were followed at an adult CHD Clinic at a single centre from 1980 to 2022 were included on their first outpatient visit. Follow-up was estimated from the time of correction surgery until one of the following events occurred first: pulmonary valve replacement, death, loss to follow-up or conclusion of the study.

RESULTS

We included 221 patients (116 males) with a median age of 19 (18-25). At a median age of 33 (10) years old, 114 (51%) patients presented significant pulmonary regurgitation. Among patients with significant pulmonary regurgitation, pulmonary valve replacement was associated with male gender, older age at surgical repair, and longer QRS duration in adulthood. Pulmonary valve replacement was performed in 50 patients, including four transcatheter pulmonary valve implantations, at a median age of 34 (14) years.

CONCLUSION

Pulmonary regurgitation affects a large percentage of tetralogy of Fallot adult patients, requiring a long-term clinical and imaging follow-up. Sex, age at surgical repair and longer QRS are associated with the need of PVR among patients with significative pulmonary regurgitation. Clinical practice and current literature support TPVI as the future gold standard intervention.

Biventricular interaction and aortic function in adult patients with repaired tetralogy of Fallot: a two-dimensional-three-dimensional speckle-tracking echocardiographic study

Aims

In patients late after correction of tetralogy of Fallot (TOF), the combined effects of pre-operative hypertrophy and hypoxia, ventricular interdependence, acquired post-operative lesions such as pulmonary or aortic regurgitation, and congenital vasculopathy may result in impaired right ventricular (RV) and left ventricular (LV) function. The aim of the present study was to investigate the interventricular interactions in repaired TOF (rTOF) and the impact of aortic function on biventricular performance using two-dimensional (2D-STE) and three-dimensional speckle-tracking echocardiography (3D-STE).

Methods and results

Twenty-five adult patients with rTOF and 25 age- and gender-matched healthy controls were studied. LV and RV volumes were determined by 3D-STE and cardiac magnetic resonance. LV and RV longitudinal strains (LVLS and RVLS) and LV and RV area strains (LVAS and RVAS) and LV twist/rotation were calculated by 3D-STE. Ascending aorta circumferential strain (AAo-CS) was obtained using 2D-STE. LV 3D-STE parameters were decreased in rTOF patients compared with controls even in patients with normal ejection fraction. AAo-CS was decreased (6.7 ± 1.9 vs. 10.1 ± 2.6, P = 0.003) in rTOF patients compared with controls even in the presence of normal aortic dimensions and correlated with AAo diameter (r = -0.69, P = 0.0001), LV twist (r = 0.54, P = 0.004), LVAS (r = -0.56, P = 0.003), and RVLS (r = -0.39, P = 0.036). LVAS and AAo-CS were associated with disease severity (peak oxygen consumption and arrhythmia occurrence). Significant improvement in global χ 2 value was noted with RV 3D-STE parameters + LVAS + AAo-CS compared with RV dysfunction alone for detecting exercise capacity impairment (from 77.1 to 84.4 to 91.2, P = 0.003).

Conclusion

Speckle-tracking echocardiography revealed subtle LV and AAo dysfunction in adults with rTOF. A correlation was observed between LV and RV strain changes and between AAo strain impairment and LV/RV dysfunction. LV and AAo changes had an incremental value in evaluating disease severity.

Tissue engineering: Relevance to neonatal congenital heart disease

Congenital heart disease (CHD) represents a large clinical burden, representing the most common cause of birth defect-related death in the newborn. The mainstay of treatment for CHD remains palliative surgery using prosthetic vascular grafts and valves. These devices have limited effectiveness in pediatric patients due to thrombosis, infection, limited endothelialization, and a lack of growth potential. Tissue engineering has shown promise in providing new solutions for pediatric CHD patients through the development of tissue engineered vascular grafts, heart patches, and heart valves. In this review, we examine the current surgical treatments for congenital heart disease and the research being conducted to create tissue engineered products for these patients. While much research remains to be done before tissue engineering becomes a mainstay of clinical treatment for CHD patients, developments have been progressing rapidly towards translation of tissue engineering devices to the clinic.

Arrhythmias in repaired pediatric and adolescent Fallot tetralogy, correlation with cardiac MRI parameters

Background

Tetralogy of Fallot (TOF) is a common congenital cyanotic heart disease in which arrhythmias could develop even after successful operative repair. Pulmonary regurgitation and right ventricular dilatation develop in many cases. The relation between arrhythmias and right ventricular dilatation is not established. Our aim is to assess the relation in between the degree of right ventricular volume affection and the severity of the pulmonary regurgitation, associated arrhythmias and the need for pulmonary valve repair in Egyptian pediatric and adolescent cases after successful TOF repair.

Results

A cross sectional descriptive study was conducted on 32 cases after successful surgical repair. Transthoracic Doppler echocardiography, 24 h Holter monitoring and cardiac MRI for assessment of pulmonary regurgitation fraction (PRF), ventricular volumes and function were measured. Cases were classified according to right ventricular end diastolic volume index (RVEDVI) into 2 groups with cut off value 150 ml/m2. Mean age of the studied cases was (12.96 ± 3.384) years, mean age at time of surgical repair was (34.23 ± 22.1) months, and mean duration postoperatively was (121.72 ± 41.028) months. Eighteen cases (56%) had RVEDVI ≥ 150 ml/m2, PRF was significantly higher in cases with increased RVEDVI (p value 0.007), with positive significant correlation between RVEDVI and PRF (p value = 0.0001, r = 0.61). Arrhythmias were detected in 18 cases (56%), the most common of which was infrequent supraventricular ectopy. No significant difference in incidence of arrhythmias between the 2 groups (p value = 1) with also no significant correlation between arrhythmias and increased RVEDVI (p value = 0.76, r = 0.05). No difference between cases with and without arrhythmias regarding RVEDVI (p value = 0.56) or PRF (p value = 0.5).

Conclusion

Holter detected arrhythmias after successful surgical repair of TOF were significantly associated with increased postoperative duration but not with PRF or RVEDVI.

Heart failure in adult congenital heart disease: tetralogy of Fallot

The number of rTOF patients who survive into adulthood is steadily rising, with currently more than 90% reaching the third decade of life. However, rTOF patients are not cured, but rather have a lifelong increased risk for cardiac and non-cardiac complications. Heart failure is recognized as a significant complication. Its occurrence is strongly associated with adverse outcome. Unfortunately, conventional concepts of heart failure may not be directly applicable in this patient group. This article presents a review of the current knowledge on HF in rTOF patients, including incidence and prevalence, the most common mechanisms of heart failure, i.e., valvular pathologies, shunt lesions, left atrial hypertension, primary left heart and right heart failure, arrhythmias, and coronary artery disease. In addition, we will review information regarding extracardiac complications, risk factors for the development of heart failure, clinical impact and prognosis, and assessment possibilities, particularly of the right ventricle, as well as management strategies. We explore potential future concepts that may stimulate further research into this field.

Tetralogy of Fallot: cardiac imaging evaluation

Thanks to advances in pediatric cardiology, most infants with tetralogy of Fallot (TOF) now survive into adulthood. This relatively new population of adult patients may face long-term complications, including pulmonary regurgitation (PR), right ventricular (RV) tract obstruction, residual shunts, RV dysfunction, and arrythmias. They will often need to undergo pulmonary valve (PV) replacement and other invasive re-interventions. However, the optimal timing for these procedures is challenging, largely due to the complexity of evaluating RV volume and function. The options for the follow-up of these patients have rapidly evolved from an angiography-based approach to the surge of advanced imaging techniques, mainly echocardiography, cardiac magnetic resonance (CMR), and computer tomography (CT). In this review, we outline the indications, strengths and limitations of these modalities in the adult TOF population.

The Role of Novel Transcatheter Procedures in Patients With Congenital Heart Disease

The development of percutaneous structural interventions in patients with acquired heart disease is happening at an exponential rate, and some of this technology is being used to treat patients with congenital heart disease. This review describes the pathophysiology of valvular abnormalities specific to congenital heart disease and discusses the application of structural procedures in this population. Although the overall experience has been encouraging, especially in high-risk patients, this article will highlight the reasons that a cautious approach to adoption of this technology is necessary in these patients.

Surgical outcomes in complex adult congenital heart disease: a brief review

Life expectancy of patients with congenital heart disease (CHD) continues to increase dramatically over the last few decades, primarily due to significant medical and surgical advancements in the field. Adult congenital heart disease (ACHD) patients are now living longer but continue to face morbidity and reduced long-term survival when compared to the general population. We briefly describe the growth of ACHD with a focus on surgical procedures and outcomes in the more complex lesions including Tetralogy of Fallot, Ebsteins Anomaly of the tricuspid valve, Coarctation of the Aorta, Transposition of the Great Arteries and single ventricle lesions. The advancing role of mechanical circulatory support and cardiac transplantation in ACHD patients is also highlighted. Cardiac surgery in these patients continues to improve with low surgical mortality rate and outstanding long-term outcomes and efficacy.

Implantation of the Edwards SAPIEN XT and SAPIEN 3 valves for pulmonary position in enlarged native right ventricular outflow tract

OBJECTIVE

Percutaneous pulmonary valve implantation (PPVI) into right ventricle-to-pulmonary artery conduits is increasingly being performed, but a few options are available for patients with a dilated native right ventricular outflow tract (RVOT), among which is the off-label use of Ed-wards SAPIEN® valves. This study reviews the results of the SAPIEN XT and SAPIEN 3 (S3) valve implantations in the pulmonary position in patients with a dilated native RVOT.

METHODS

Between January 2015 and March 2020, PPVI procedures were performed on 129 patients. Among them, 103 (80%) had dilated native RVOT, 86 of whom were eligible for PPVI prestenting and valve implantation. Retrospective analysis was performed on 84 patients who have undergone successful PPVI implantation using the SAPIEN XT or S3 valves with dilated native RVOT.

RESULTS

The procedural success rate was 84/86 (98%). The median age was 18.7 years (8-46 years), and the median weight was 57 kg (22-102 kg). The primary underlying diagnosis was tetralogy of Fallot (n=77/84). Stenting was performed simultaneously with valve implantation in 50/84 (60%) cases-six of which were hybrid procedures-whereas prestenting was performed 3 to 14 weeks earlier in 34/84 cases. Before valve im-plantation, the median right anterior oblique and lateral diameters of the stents were 26 mm (20-32 mm) and 28 mm (21-32 mm). Valve sizes were 26 mm (n=13) and 29 mm (n=64) for XT and 29 mm (n=7) for S3. In 59 patients, an additional 1-5 ml (median 2 ml) volume was added to the valves' balloons for stabilization. In all hybrid procedures, the stent and valve were implanted in the same session. During follow-ups of 1 to 59 months (median 14 months), no deaths were reported, 3 patients developed tricuspid regurgitation secondary to the procedure, and valves continued to function in all patients.

CONCLUSION

The Edwards SAPIEN XT and S3 valves may be an alternative to PPVI in patients with dilated native RVOT.

Tetralogy of Fallot Repair in Developing Countries: International Quality Improvement Collaborative

BACKGROUND

Isolated reports from low- and middle-income countries (LMICs) for surgical results in tetralogy of Fallot (TOF) are available. The International Quality Improvement Collaborative for Congenital Heart Disease (IQIC) seeks to improve surgical results promoting reductions in infection and mortality in LMICs.

METHODS

All cases of TOF in the IQIC database performed between 2010 and 2014 at 32 centers in 20 LMICs were included. Excluded from the analysis were TOF with any associated lesions. A logistic regression analysis was performed to identify risk factors for in-hospital mortality after surgery for TOF.

RESULTS

A total of 2,164 patients were identified. There were 1,839 initial primary repairs, 200 with initial systemic-to-pulmonary artery shunt, and 125 underwent secondary repair after initial palliation. Overall mortality was 3.6% (78 of 2,164), initial primary repair was 3.3% (60 of 1,839), initial systemic-to-pulmonary artery shunt was 8.0% (16 of 200), and secondary repair was 1.6% (2 of 125; p = 0.003). Major infections occurred in 5.9% (128 of 2,164) of the entire cohort. Risk factors for death after the initial primary repair were oxygen saturation less than 90% and weight/body mass index for age below the fifth percentile (p < 0.001). The initial primary repair occurred after age 1 year in 54% (991 of 1,839). Older age at initial primary repair was not a risk factor for death (p = 0.21).

CONCLUSIONS

TOF patients are often operated on after age 1 year in LMICs. Unlike in developed countries, older age is not a risk factor for death. Nutritional and hypoxemic status were associated with higher mortality and infection. This information fills a critical knowledge gap for surgery in LMIC.

Pulmonary Valve Regurgitation: Neither Interventional Nor Surgery Fits All

Introduction: PV implantation is indicated for severe PV regurgitation after surgery for congenital heart defects, but debates accompany the following issues: timing of PV implantation; choice of the approach, percutaneous interventional vs. surgical PV implantation, and choice of the most suitable valve. Timing of pulmonary valve implantation: The presence of symptoms is class I evidence indication for PV implantation. In asymptomatic patients indication is agreed for any of the following criteria: PV regurgitation > 20%, indexed end-diastolic right ventricular volume > 120-150 ml/m2 BSA, and indexed end-systolic right ventricular volume > 80-90 ml/m2 BSA. Choice of the approach: percutaneous interventional vs. surgical: The choice of the approach depends upon the morphology and the size of the right ventricular outflow tract, the morphology and the size of the pulmonary arteries, the presence of residual intra-cardiac defects and the presence of extremely dilated right ventricle. Choice of the most suitable valve for surgical implantation: Biological valves are first choice in most of the reported studies. A relatively large size of the biological prosthesis presents the advantage of avoiding a right ventricular outflow tract obstruction, and also of allowing for future percutaneous valve-in-valve implantation. Alternatively, biological valved conduits can be implanted between the right ventricle and pulmonary artery, particularly when a reconstruction of the main pulmonary artery and/or its branches is required. Hybrid options: combination of interventional and surgical: Many progresses extended the implantation of a PV with combined hybrid interventional and surgical approaches. Major efforts have been made to overcome the current limits of percutaneous PV implantation, namely the excessive size of a dilated right ventricular outflow tract and the absence of a cylindrical geometry of the right ventricular outflow tract as a suitable landing for a percutaneous PV implantation. Conclusion: Despite tremendous progress obtained with modern technologies, and the endless fantasy of researchers trying to explore new forms of treatment, it is too early to say that either the interventional or the surgical approach to implant a PV can fit all patients with good long-term results.

Sex-specific aspects of left and right ventricular volume regulation in patients following tetralogy of Fallot repair

Ejection fraction (EF) is applied as a clinically relevant metric to assess both left (LV) and right ventricular (RV) function. EF depends on the interplay between end-systolic volume (ESV) and end-diastolic volume (EDV). The role of the two constitutive components is of particular interest for the follow-up study of Fallot patients at risk for RV volume overload. The volume regulation graph (VRG) relates ESV to EDV and has been advanced as a central tool to describe LV and RV function. The method permits additional analysis of the impact of clinically relevant determinants such as sex and age. Following Fallot repair and using MRI we evaluated LV and RV volumes in 124 patients (50 females), who were not taking any medication. Volumes were indexed for body surface area (BSA). The VRG regression lines are similar for both sexes, also when stratified for age (i.e. younger or older than 18 years), and different for LV and RV. However, RV ESV is larger (P=0.039) for adult males, as is RV EDV (P=0.026) in boys, relative to their female counterparts. For LV ESV we also found larger volumes, but only in boys (P=0.023) compared to girls. Average EF (only for RV) is lower in adult men compared to women (P=0.012), and to boys (P=0.007). These findings are partly in contrast with common observations made in individuals without a history of cardiac disease, where (with BSA indexation) LV and RV volumes are similar in children, but consistently larger in adult males. These results highlight the age- and sex-specific volumetric aspects of remodeling following surgery in Fallot patients, and emphasize the pivotal role of ESV size in both RV and LV.

Trifecta St. Jude medical® aortic valve in pulmonary position

Introduction: To evaluate an aortic pericardial valve for pulmonary valve (PV) regurgitation after repair of congenital heart defects.

Methods: From July 2012 to June 2016 71 patients, mean age 24 ± 13 years (four to years) underwent PV implantation of aortic pericardial valve, mean interval after previous repair = 21 ± 10 years (two to 47 years). Previous surgery at mean age 3.2 ± 7.2 years (one day to 49 years): tetralogy of Fallot repair in 83% (59/71), pulmonary valvotomy in 11% (8/71), relief of right ventricular outflow tract (RVOT) obstruction in 6% (4/71). Pre-operative echocardiography and MRI showed severe PV regurgitation in 97% (69/71), moderate in 3% (2/71) with associated RVOT obstruction. MRI and knowledge-based reconstruction 3D volumetry (KBR-3D-volumetry) showed mean PV regurgitation = 42 ± 9% (20–58%), mean indexed RV end-diastolic volume = 169 ± 33 (130–265) ml m^–2 BSA and mean ejection fraction (EF) = 46 ± 8% (33–61%). Cardio-pulmonary exercise showed mean peak O₂/uptake = 24 ± 8 ml kg^–1 min^–1 (14–45 ml kg^–1 min^–1), predicted max O₂/uptake 66 ± 17% (26–97%). Pre-operative NYHA class was I in 17% (12/71) patients, II in 70% (50/71) and III in 13% (9/71).

Results: Mean cardio-pulmonary bypass duration was 95 ± 30ʹ (38–190ʹ), mean aortic cross-clamp in 23% (16/71) 46 ± 31ʹ (8–95ʹ), with 77% (55/71) implantations without aortic cross-clamp. Size of implanted PV: 21 mm in seven patients, 23 mm in 33, 25 mm in 23, and 27 mm in eight. The z-score of the implanted PV was −0.16 ± 0.80 (−1.6 to 2.5), effective orifice area indexed (for BSA) of native PV was 1.5 ± 0.2 (1.2 to –2.1) vs. implanted PV 1.2 ± 0.3 (0.76 to –2.5) (p = ns). In 76% (54/71) patients surgical RV modelling was associated. Mean duration of mechanical ventilation was 6 ± 5 h (0–26 h), mean ICU stay 21 ± 11 h (12–64 h), mean hospital stay 6 ± 3 days (three to 19 days). In mean follow-up = 25 ± 14 months (six to 53 months) there were no early/late deaths, no need for cardiac intervention/re-operation, no valve-related complications, thrombosis or endocarditis. Last echocardiography showed absent PV regurgitation in 87.3% (62/71) patients, trivial/mild degree in 11.3% (8/71), moderate degree in 1.45% (1/71), mean max peak velocity through RVOT 1.6 ± 0.4 (1.0–2.4) m s^–1. Mean indexed RV end-diastolic volume at MRI/KBR-3D-volumetry was 96 ± 20 (63–151) ml m^–2 BSA, lower than pre-operatively (p < 0.001), and mean EF = 55 ± 4% (49–61%), higher than pre-operatively (p < 0.05). Almost all patients (99% = 70/71) remain in NYHA class I, 1.45% = 1/71 in class II.

Conclusion: (a) Aortic pericardial valve is implantable in PV position with an easy and reproducible surgical technique; (b) valve size adequate for patient BSA can be implanted with simultaneous RV remodelling; (c) medium-term outcomes are good with maintained PV function, RV dimensions significantly reduced and EF significantly improved; (d) adequate valve size will allow later percutaneous valve-in-valve implantation.