Meta-analysis of pulmonary valve replacement after operative repair of tetralogy of fallot

A Novel Modification of the Melody Valve in a Short Right Ventricle-Pulmonary Artery Conduit: A Case Report

Pulmonary insufficiency often follows the surgical repair of tetralogy of Fallot, leading to adverse outcomes. Young patients with short right ventricle-pulmonary artery conduits are at risk of pulmonary artery branch occlusion when a traditional Melody valve (Medtronic) is used. We report a novel case of a folded Melody valve implanted with a simultaneous stent in a pediatric patient to address challenges posed by a short right ventricle-pulmonary artery conduit.

Pulmonary Artery Angioplasty for Improving Ipsilateral Lung Perfusion in Adolescent and Adult Patients: An Analysis Based on Cardiac Magnetic Resonance Imaging and Lung Perfusion Scanning

Background

The left pulmonary artery (LPA) may be kinked and stenotic, especially in tetralogy of Fallot, because of ductal tissue and anterior deviation of the conal septum. If LPA stenosis is not effectively treated during total correction, surgical angioplasty is occasionally performed. However, whether pulmonary artery (PA) angioplasty in adolescents or adults improves perfusion in the ipsilateral lung remains unclear.

Methods

This retrospective review enrolled patients who underwent PA angioplasty for LPA stenosis between 2004 and 2019. Among patients who underwent a lung perfusion scan (LPS) or cardiac magnetic resonance imaging (cMRI) pre- and post-pulmonary angioplasty, those aged >13 years with <40% left lung perfusion (p-left) in the pre-angioplasty study were included. Preoperative and postoperative computed tomography, LPS, and cMRI data were collected. The perfusion ratio was analyzed according to the LPA's anatomical characteristics.

Results

Seventeen adolescents and 16 adults (≥18 years old) were finally included (median age, 17 years). The most common primary diagnosis was tetralogy of Fallot (87.9%). In all patients, LPA angioplasty was performed concomitantly with right ventricular outflow tract reconstruction. No patients died. Preoperative p-left was not significantly different between adolescents and adults; however, adolescents had significantly higher postoperative p-left than adults. P-left significantly increased in adolescents, but not in adults. Seven patients had significant stenosis (z-score <-2.0) confined only to the proximal LPA and demonstrated significantly increased p-left.

Conclusion

PA angioplasty significantly increased ipsilateral lung perfusion in adolescents. If focal stenosis is confined to the proximal LPA, PA angioplasty may improve ipsilateral lung perfusion, regardless of age.

Technical recommendations for computed tomography guidance of intervention in the right ventricular outflow tract: Native RVOT, conduits and bioprosthetic valves:: A white paper of the Society of Cardiovascular Computed Tomography (SCCT), Congenital Heart Surgeons' Society (CHSS), and Society for Cardiovascular Angiography & Interventions (SCAI)

This consensus document for the performance of Cardiovascular Computed Tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multi-modality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits, and Bioprosthetic Valves

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital heart disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons, and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multimodality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits and Bioprosthetic Valves: A White Paper of the Society of Cardiovascular Computed Tomography (SCCT), Congenital Heart Surgeons' Society (CHSS), and Society for Cardiovascular Angiography & Interventions (SCAI)

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multi-modality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Characterization of Favorable Right Ventricular Dimensions for Optimal Reverse Remodeling Following Pulmonary Valve Replacement

We sought to couple current cardiac magnetic resonance (CMR) thresholds of right ventricular (RV) size and function with longitudinal trajectories of RV recovery, after pulmonary valve replacement (PVR). We aimed to identify optimal timing of PVR and couple CMR-based metrics with contemporaneous echocardiographic metrics. From June 2002 to January 2019, 174 patients with severe pulmonary regurgitation and peak RV outflow tract gradient <30 mm Hg underwent PVR at Cleveland Clinic. Mean age was 35 ± 16 years and 60 (34%) had concomitant tricuspid valve surgery. RV end diastolic area index (RVEDAi) and function metrics were measured by offline image review on preoperative and 794 postoperative echocardiograms. Contemporaneous RV end diastolic volume index (RVEDVi) was assessed on CMR and correlated to RVEDAi. Multiphase nonlinear mixed-effects models were used to analyze the longitudinal change in RV size and function after PVR. RVEDAi was correlated with RVEDVi (P < 0.0001, r = 0.59). RVEDAi decreased slowly over 10 years following PVR. An inflection point at 24 cm2/m2 was noted at 1 year post-PVR and was associated with failure of RV reverse remodeling and RVEDVi ≥150 mL/m2. Compared to patients with preoperative RVEDVi ≥150 mL/m2, patients with RVEDVi <150 mL/m2 had accelerated recovery of longitudinal trajectories of RV size and function metrics on echocardiograms. Reverse remodeling of RV following PVR is an ongoing process. Current accepted threshold values for PVR are associated with greatest RV recovery, suggesting that earlier PVR is warranted. Echocardiography can potentially be utilized in lieu of CMR for surveillance and interventional triage.

Long-Term Results after Fallot Repair

BACKGROUND

 The aim of this study was to evaluate the long-term outcome and freedom from pulmonary valve replacement (PVR) after initial repair of tetralogy of Fallot (TOF).

PATIENTS AND METHODS

 The cohort of 306 patients treated between 1980 and 2017 was divided into anatomical subgroups according to the diagnosis of TOF-pulmonary stenosis, TOF-pulmonary atresia and TOF-double outlet right ventricle. Patients were treated with transannular patch (TAP), valve sparing repair (VSR), or conduits from the right ventricle to the pulmonary arteries (RVPA conduits).

RESULTS

 There were 21 deaths (6.9%), 14 being hospital deaths (4.6%) after primary correction and four deaths (1.3%) occurred after PVR. One patient died after a non-cardiac operation (0.3%). There were two late deaths (0.7%). During the past 12 years no early mortality has been observed. Ninety-one patients (30.4%) received PVR after a median of 12.1 ± 7.0 years with an early mortality of 4.4% (n = 4) and no late mortality. A significant difference in freedom from reoperation after TAP, VSR, and RVPA-conduits could be identified. Multivariate analysis displayed transannular repair (p = 0.016), primary palliation (p <0.001), the presence of major aortopulmonary collateral arteries (MAPCA; p = 0.023), and pulmonary valve Z-scores < - 4.0 (p = 0.040) as significant risk factors for PVR.

CONCLUSION

 TOF repair has a beneficial long-term prognosis with low morbidity and mortality. Pulmonary valve Z-scores < - 4.0, transannular repair, and presence of MAPCAs are associated with earlier PVR. Non-VSRs and TOF-pulmonary atresia lead to earlier reoperation but have no negative impact on survival.

Pediatric Surgical Pulmonary Valve Replacement Outcomes After Implementation of a Clinical Pathway

BACKGROUND

Standardization of perioperative care can reduce resource utilization while improving patient outcomes. We sought to describe our outcomes after the implementation of a perioperative clinical pathway for pediatric patients undergoing elective surgical pulmonary valve replacement and compare these results to previously published national benchmarks.

METHODS

A retrospective single-center descriptive study was conducted of all pediatric patients who underwent surgical pulmonary valve replacement from 2017 through 2020, after the implementation of a clinical pathway. Outcomes included hospital length of stay and 30-day reintervention, readmission, and mortality.

RESULTS

Thirty-three patients (55% female, median age 11 [7, 13] years, 32 [23, 44] kg) were included in the study. Most common diagnosis and indication for surgery was Tetralogy of Fallot (61%) with pulmonary valve insufficiency (88%). All patients had prior cardiac surgery. Median hospital length of stay was 2 [2, 2] days, and longest length of stay was three days. There were no 30-day readmissions, reinterventions, or mortalities. Median follow-up time was 19 [9, 31] months.

CONCLUSIONS

Formalization of a perioperative surgical pulmonary valve replacement clinical pathway can safely promote short hospital length of stay without any short-term readmissions or reinterventions, especially when compared with previously published benchmarks. Such formalization enables the dissemination of best practices to other institutions to reduce hospital length of stay and limit costs.

Tricuspid Valve Repair at Pulmonary Valve Replacement in Repaired Tetralogy of Fallot

BACKGROUND

Pulmonary valve replacement (PVR) is often performed in patients with repaired tetralogy of Fallot (TOF). Concomitant tricuspid valvuloplasty (TVP) in those with tricuspid regurgitation (TR) at the time of PVR is still controversial.

METHOD

We retrospectively reviewed clinical records of patients who underwent PVR between 2001 and 2012. We analyzed the impact of concomitant TVP on the tricuspid valve function and right ventricle function and size in mid-term.

RESULTS

119 patients with mild to moderate TR at the time of PVR were enrolled. 33 patients underwent concomitant TVP (TVP group) and 86 patients underwent PVR alone (no-TVP group). There was a significant reduction of TR (p < 0.001) and right ventricular end-diastolic volume index (RVEDVi) (p < 0.001). However, in patients who showed prosthetic pulmonary valve (PV) failure at the last follow-up, there was no significant decrease in TR regardless of concomitant TVP. In the patients with preserved prosthetic PV function, TR was significantly improved (p < 0.001 in both groups). The multivariable analysis showed that significant risk factors for recurrence of significant TR were preoperative moderate TR and prosthetic PV failure.

CONCLUSIONS

After PVR in repaired TOF patients, there was an improvement in the degree of TR and the RVEDVi. Concomitant TVP at the time of PVR may not be able to prevent the recurrence of TR when prosthetic PV failure occurs; however, it may effectively preserve tricuspid valve function until that time.

Pulmonary Valve Replacement in Repaired Tetralogy of Fallot: Midterm Impact on Biventricular Response and Adverse Clinical Outcomes

BACKGROUND

Pulmonary regurgitation (PR), though well tolerated for short term in patients with repaired tetralogy of Fallot (rTOF), could lead to right ventricular (RV) dysfunction, arrhythmias, and sudden cardiac death. Pulmonary valve replacement (PVR), considered as the gold-standard treatment for PR, is performed to mitigate these late effects. In this study, we aimed to evaluate the midterm outcomes and predictors of adverse clinical outcomes (ACO).

METHODS

From May 2014 to December 2017, 42 patients with rTOF undergoing surgical or transcatheter PVR in our department were retrospectively included. Cardiovascular magnetic resonance was performed before PVR (pre-PVR), early after PVR (early post-PVR), and midterm after PVR (midterm post-PVR). Medical history and individual data were collected from medical records. ACO included all-cause death, new-onset arrhythmia, prosthetic valve failure, and repeat PVR.

RESULTS

The median follow-up duration was 4.7 years. PVR was performed at a median age of 21.6 years. There was no early or late death. Freedom from ACO at 3 and 5 years was 88.1 ± 5% and 58.2 ± 9%, respectively. RV end-diastolic volume index (RVEDVI) and end-systolic volume index (RVESVI) significantly reduced early after PVR and further decreased by midterm follow-up (pre-PVR vs. early post-PVR vs. midterm post-PVR: RVEDVI, 155.2 ± 34.7 vs. 103.8 ± 31.2 vs. 95.1 ± 28.6 ml/m², p < 0.001; RVESVI, 102.9 ± 28.5 vs. 65.4 ± 28.2 vs. 57.7 ± 23.4 ml/m², p < 0.001). Multivariable analysis revealed that the occurrence of ACO was significantly increased in patients with lower left ventricular end-systolic volume index.

CONCLUSIONS

A significant reduction of RV volume occurred early after PVR, followed by a further improvement of biventricular function by midterm follow-up. The midterm freedom from ACO was favorable.

Cardiac MRI-Derived Myocardial Deformation Parameters Correlate with Pulmonary Valve Replacement Indications in Repaired Tetralogy of Fallot

Right ventricular (RV) volumetric cardiac magnetic resonance (CMR) criteria serve as indicators for pulmonary valve replacement (PVR) in repaired tetralogy of Fallot (rTOF). Myocardial deformation and tricuspid valve displacement parameters may be more sensitive measures of RV dysfunction. This study's aim was to describe rTOF RV deformation and tricuspid displacement patterns using novel CMR semi-automated software and determine associations with standard CMR measures. Retrospective study of 78 pediatric rTOF patients was compared to 44 normal controls. Global RV longitudinal and circumferential strain and strain rate (SR) and tricuspid valve (TV) displacement were measured. Correlation analysis between strain, SR, TV displacement, and volumes was performed between and within subgroups. The sensitivity and specificity of strain parameters in predicting CMR criteria for PVR was determined. Deformation variables were reduced in rTOF compared to controls. Decreased RV strain and TV shortening were associated with increased RV volumes and decreased RVEF. Longitudinal and circumferential parameters were predictive of RVESVi (> 80 ml/m2) and RVEF (< 47%), with circumferential strain (> - 15.88%) and SR (> - 0.62) being most sensitive. Longitudinal strain was unchanged between rTOF subgroups, while circumferential strain trended abnormal in those meeting PVR criteria compared to controls. RV deformation and TV displacement are abnormal in rTOF, and RV circumferential strain variation may reflect an adaptive response to chronic volume or pressure load. This coupled with associations of ventricular deformation with traditional PVR indications suggest importance of this analysis in the evolution of rTOF RV assessment.

Health-related quality of life in adults with tetralogy of Fallot repair: a systematic review and meta-analysis

BACKGROUND

With the advancement in diagnostics and clinical management, patients with Tetralogy of Fallot (ToF) are surviving till adulthood. Hence, assessing the impact of ToF repair on health-related quality of life (HRQOL) of these patients is becoming increasingly important. The objective of this paper is to conduct a systematic review and meta-analysis of the HRQOL in patients who have undergone ToF repair.

METHODS

A systematic search was conducted using PubMed, CINAHL, Medline and Web of Science databases. Studies that compared the HRQOL of adult patients (mean age ≥ 18 years) who had previously undergone ToF repair with healthy controls were included. Analysis was done via Revman V5.3 using a random effects model.

RESULTS

The 16 studies (15 using SF-36) included in the meta-analysis, comprised 1818 patients and 50,265 healthy controls. There was a higher proportion of males (59%). The mean ages at surgery and at HRQOL assessment were 5.37 years and 30.3 years, respectively. We found that repaired ToF patients had a statistically significantly lower score in the physical component summary (SMD = - 0.92 CI = - 1.54, - 0.30) and physical functioning (SMD = - 0.27 CI = - 0.50, - 0.03) compared to healthy controls. However, these patients had statistically significantly higher scores in the bodily pain domain (SMD = 0.35 CI = 0.12, 0.58) and social functioning (SMD = 0.23 CI = 0.01, 0.46), while there was no significant difference in other domains.

CONCLUSION

Overall, physical domain of HRQOL was statistically significantly lower in repaired ToF patients compared to healthy controls. However, repaired ToF patients scored significantly higher on bodily pain and Social Functioning. There was additionally no difference in the HRQOL between the two groups in other domains of HRQOL.

Unchanged right ventricular strain in repaired tetralogy of Fallot after pulmonary valve replacement with radial long-axis cine magnetic resonance images

We measured right ventricular (RV) strain by applying a novel postprocessing technique to conventional short-axis cine magnetic resonance imaging in the repaired tetralogy of Fallot (TOF) and investigated whether pulmonary valve replacement (PVR) changes the RV strain. Twenty-four patients with repaired TOF who underwent PVR and 16 healthy controls were enrolled. Global maximum and minimum principal strains (GPS_max, GPS_min) and global circumferential and longitudinal strains (GCS, GLS) were measured from short-axis cine images reconstructed radially along the long axis. Strain parameters before and after PVR were compared using paired t-tests. One-way ANOVA with Tukey post-hoc analysis was used for comparisons between the before and after PVR groups and the control group. There were no differences in strain parameters before and after PVR. The GPS_max before PVR was lower than that in the control group (P = 0.002). Before and after PVR, GCSs were higher and GLSs were lower than those in the control group (before and after GCSs: P = 0.002 for both, before and after GLSs: P < 0.0001 and P = 0.0003). RV strains from radially reconstructed short-axis cine images revealed unchanged myocardial motion after PVR. When compared to the control group, changes in GCS and GLS in TOF patients before and after PVR might be due to RV remodeling.

Outcomes of adults with repaired tetralogy of Fallot from the national Scottish Cohort

BACKGROUND

The adult population of repaired tetralogy of Fallot is increasing and at risk of pre-mature death and arrhythmia. This study evaluates risk factors for adverse outcome and the effect of pulmonary valve replacement within a national cohort.

METHODS

A retrospective cohort study of 341 adult repaired tetralogy of Fallot (16-72 years) managed through a single national service was undertaken incorporating over 1200 patient-years of follow-up. Demographics, cardiopulmonary exercise testing, cardiac magnetic resonance, reintervention (including pulmonary valve replacement), and clinical events were analysed. The influence of these parameters on a primary outcome (death or arrhythmia) was evaluated.

RESULTS

Compared with an age-/gender-matched population, patients experienced a reduced survival, particularly males over 55 years (standardised mortality ratio : 6.12, 95% CI: 1.64-15.66, p = 0.004). Cox proportional hazards modelling identified increased indexed right ventricle (RV) end-diastolic volume (hazard ratio (HR): 2.86, 95% CI: 1.4-5.85, p = 0.004) and female gender (HR (male): 0.37, 95% CI: 0.14-0.98, p = 0.045) to be predictors significantly associated with the primary outcome. Pulmonary valve replacement undertaken at indexed RV end-diastolic volume = 145 ml/m2 reduced RV volumes and QRS duration but did not improve cardiopulmonary exercise testing nor NYHA class. Pulmonary valve replacement during cohort period was associated with increased risk of primary outcome (HR: 2.82, 95% CI: 1.36-5.86, p = 0.005).

CONCLUSIONS

Although the majority of adult tetralogy of Fallot were asymptomatic in NYHA 1, cardiopulmonary exercise testing revealed important deficits. Tetralogy of Fallot survival was reduced compared to the general population. Female gender and increasing RV end-diastolic volume predicted adverse events. Pulmonary valve replacement reduced RV volumes and QRS duration but did not improve primary outcome.

Impact of pulmonary valve replacement on left ventricular rotational mechanics in repaired tetralogy of Fallot

BACKGROUND

In repaired tetralogy of Fallot (rTOF), abnormal left ventricular (LV) rotational mechanics are associated with adverse clinical outcomes. We performed a comprehensive analysis of LV rotational mechanics in rTOF patients using cardiac magnetic resonance (CMR) prior to and following surgical pulmonary valve replacement (PVR).

METHODS

In this single center retrospective study, we identified rTOF patients who (1) had both a CMR ≤ 1 year before PVR and ≤ 5 years after PVR, (2) had no other intervening procedure between CMRs, (3) had a body surface area > 1.0 m2 at CMR, and (4) had images suitable for feature tracking analysis. These subjects were matched to healthy age- and sex-matched control subjects. CMR feature tracking analysis was performed on a ventricular short-axis stack of balanced steady-state free precession images. Measurements included LV basal and apical rotation, twist, torsion, peak systolic rates of rotation and torsion, and timing of events. Associations with LV torsion were assessed.

RESULTS

A total of 60 rTOF patients (23.6 ± 7.9 years, 52% male) and 30 healthy control subjects (20.8 ± 3.1 years, 50% male) were included. Compared with healthy controls, rTOF patients had lower apical and basal rotation, twist, torsion, and systolic rotation rates, and these parameters peaked earlier in systole. The only parameters that were correlated with LV torsion were right ventricular (RV) end-systolic volume (r = - 0.28, p = 0.029) and RV ejection fraction (r = 0.26, p = 0.044). At a median of 1.0 year (IQR 0.5-1.7) following PVR, there was no significant change in LV rotational parameters versus pre-PVR despite reductions in RV volumes, RV mass, pulmonary regurgitation, and RV outflow tract obstruction.

CONCLUSION

In this comprehensive study of CMR-derived LV rotational mechanics in rTOF patients, rotation, twist, and torsion were diminished compared to controls and did not improve at a median of 1 year after PVR despite favorable RV remodeling.

Outcomes of percutaneous and surgical pulmonary valve implantation

BACKGROUND

The objective of this study is to describe the recent trends and in-hospital outcomes with percutaneous pulmonic valve implantation (PPVI) and surgical pulmonic valve implantation (SPVR) in adult hospitals in the US after the availability of both the Melody valve (Medtronic Inc., Minneapolis, Minnesota) and the Sapien XT valve (Edwards Lifesciences, Irvine, CA).

METHODS

We queried the National Inpatient Sample database (NIS) from January 2016 to December 2017 to identify hospitalizations for PPVI and SPVR.

RESULTS

We identified 5455 weighted discharges with PPVI and SPVR (PPVI=1140, SPVR=4305). PPVI procedures had increased in number over 2016 and 2017 (115 procedure at the first quarter of 2016, 195 procedures in the final quarter of 2017, P-trend=0.086), while SPVR volume remained constant. The incidence of in-hospital mortality was low with both procedures (SPRV: 1.6% vs. PPVI: 0.9%, p=0.071). SPVR had worse in-hospital outcomes, was associated with a longer length of stay [5 days vs. 1 day, p<0.001], and comparable cost of index hospitalization [$51,657 vs. $51,193] compared with PPVI.

CONCLUSION

After approval of the Sapien valve for commercial use in 2016, PPVI procedures have increased in frequency. PPVI is associated with lower procedural complications than SPVR, however, both carry a low risk of mortality. Despite the higher cost of the valves and delivery systems, PPVI is associated with a slightly lower cost of index hospitalization compared with SPVR, likely due to the higher in-hospital complications and LOS of the latter.

Effect of Pulmonary Valve Replacement in the Repaired Tetralogy of Fallot Patients with Trans-annular Incision: More than 20 Years of Follow-up

BACKGROUND AND OBJECTIVES

We reviewed the long-term outcomes after tetralogy of Fallot (TOF) repair with trans-annular incision; and evaluated the effectiveness of pulmonary valve replacement (PVR) on outcomes.

METHODS

This was a retrospective review of clinical outcomes of 180 of 196 TOF patients who underwent total correction with trans-annular incision from 1991 to 1997 (PVR group: 81; non-PVR group: 99).

RESULTS

The median age of the patients was 14.0 months (interquartile range [IQR], 10.7-19.8 months) at TOF repair. Ten in-hospital deaths (5.1%) occurred. During the follow-up, 81 patients underwent PVR at the median age of 13.5 years (IQR, 11.2-17.1 years). The patients in PVR group showed better outcomes than non-PVR group in overall survival rate (100% in PVR vs. 88.7% in non-PVR, p=0.007), in all adverse events (arrhythmia, neurologic complications, 95.5% in PVR vs. 74.6% in non-PVR, p=0.024) at 20 years. Age at TOF repair younger than 1 year (hazard ratio [HR], 2.265; p=0.01) and previous shunt history (HR, 2.195; p=0.008) were predictive for requiring PVR. During follow-up, 10 late deaths (5 sudden deaths) occurred in the non-PVR group, mainly due to ventricular arrhythmia and right ventricular failure; there was 1 late death (not a sudden death) in the PVR group.

CONCLUSIONS

Long-term survival after repair of TOF with trans-annular incision were acceptable. However, arrhythmias were frequently observed during 20 years of follow-up. The patient age <1 year at the time of TOF repair and shunt implantation prior to TOF repair were predictive factors for requiring PVR.

Pulmonary Valve Replacement in Tetralogy of Fallot: An Updated Meta-Analysis

BACKGROUND

The benefits of pulmonary valve replacement (PVR) for pulmonary insufficiency in patients with repaired tetralogy of Fallot are still incompletely understood, and optimal timing remains challenging.

METHODS

We systematically reviewed databases (PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials /Cochrane Controlled Trials Register, ClinicalTrials.gov, Scientific Electronic Library Online, Literatura Latino Americana em Ciências da Saúde, and Google Scholar) and reference lists of relevant articles for studies about PVR in repaired tetralogy of Fallot patients that reported any of the following outcomes: mortality and redo PVR rates, right ventricular (RV) and left ventricular measures, QRS duration, cardiopulmonary exercise test results, or brain natriuretic peptide. In addition to calculating the pooled treatment effects using a random-effects meta-analysis, we evaluated the effect of preoperative measures on PVR outcomes using meta-regressions.

RESULTS

Eighty-four studies involving 7544 patients met the eligibility criteria. Pooled mortality at 30 days, 5 years, and 10 years after PVR was 0.87% (63 of 7253 patients, 80 studies), 2.7% (132 of 4952 patients, 37 studies), and 6.2% (510 of 2765 patients, 15 studies), respectively. Pooled 5- and 10-year redo PVR rates were 3.7% (141 of 3755 patients, 23 studies) and 16.8% (172 of 3035 patients, 16 studies), respectively. The results of the previous meta-analysis could be confirmed. In addition, we demonstrated that after PVR (1) QRS duration, cardiopulmonary exercise test results, and RV and left ventricular measures longitudinal strain do not significantly change; (2) brain natriuretic peptide decreases; and (3) greater indexed RV end-diastolic and end-systolic volumes are associated with lower chances of RV volume normalization after PVR.

CONCLUSIONS

This updated meta-analysis provides evidence about the benefits of PVR.

Ventricular Myocardial Deformation Imaging of Patients with Repaired Tetralogy of Fallot

In patients with repaired tetralogy of Fallot (TOF), dysfunction of the right and left ventricles remains an important issue. Adverse right ventricular (RV) remodeling has been related to RV dilation secondary to pulmonary regurgitation, electromechanical dyssynchrony, and myocardial fibrosis. Left ventricular (LV) dysfunction is attributed among other factors to altered ventricular-ventricular interaction. Advancements in echocardiography and cardiac magnetic resonance imaging have enabled direct interrogation of myocardial deformation of both ventricles in terms of myocardial strain and strain rate. Emerging evidence suggests that myocardial deformation imaging may provide incremental information for clinical use. In children and adults with repaired TOF, there is a growing body of literature on the use of myocardial deformation imaging in the assessment of ventricular mechanics and its clinical and prognostic values. The present review aims to provide an overview of impairment in RV and LV mechanics, associations between RV and LV deformation, changes in ventricular deformation after pulmonary valve replacement, and associations between measures of RV and LV deformation and outcomes and to highlight the clinical translational potential of myocardial deformation imaging in patients with repaired TOF.

Identifying Risk Factors for Massive Right Ventricular Dilation in Patients With Repaired Tetralogy of Fallot

In repaired tetralogy of Fallot (rTOF), pulmonary insufficiency results in varying degrees of right ventricle (RV) dilation. A subset of patients is diagnosed at initial cardiac magnetic resonance imaging (CMR) with a massively dilated RV, far beyond pulmonary valve replacement (PVR) criteria, which is unlikely to return to normal size after PVR. This study aimed to identify risk factors for massive RV dilation at initial CMR. This nested case-control study included all patients at our institution with rTOF and massive RV dilation (indexed RV end-diastolic volume [RVEDVi] ≥200 ml/m²) on initial CMR. Patients were matched by age at first CMR, gender, and type of repair with rTOF controls with RVEDVi<200 ml/m². In 39 cases (median RVEDVi 227 ml/m², interquartile range [IQR] 213 to 250) and 73 controls (median RVEDVi 155 ml/m², IQR 130 to 169), repair at >6 months of age, longer QRS duration, and non-Caucasian race were significantly associated with massive RV dilation on univariate analysis. In multivariate analysis, repair at >6 months of age (adjusted odds ratio [AOR] 2.90, 95% confidence interval [CI] 1.12 to 7.55, p = 0.03), longer QRS duration (AOR = 1.03, 95% CI 1.01 to 1.05, p = 0.005), and non-Caucasian race (AOR = 7.84, 95% CI 1.76 to 34.8, p = 0.01) remained independently associated with massive RV dilation. Era of repair, history of systemic to pulmonary shunt palliation, genetic anomaly, and additional cardiac lesions did not differ between groups. In conclusion, these risk factors identify a subset of patients who may benefit from earlier CMR evaluation to avoid massive irreversible RV dilation.

Pulmonary Valve Replacement for Pulmonary Regurgitation in Adults With Tetralogy of Fallot: A Meta-analysis-A Report for the Writing Committee of the 2019 Update of the Canadian Cardiovascular Society Guidelines for the Management of Adults With Congenital Heart Disease

BACKGROUND

There is no systematic evidence review of the long-term results of surgical pulmonary valve replacement (PVR) dedicated to adults with repaired tetralogy of Fallot (rTOF) and pulmonary regurgitation.

METHODS

Our primary objective was to determine whether PVR reduced long-term mortality in adults with rTOF compared with conservative therapy. Secondary objectives were to determine the postoperative incidence rate of death, the changes in functional capacity and in right ventricular (RV) volumes and ejection fraction after PVR, and the postoperative incidence rate of sustained ventricular arrhythmias. A systematic search of multiple databases for studies was conducted without limits.

RESULTS

No eligible randomized controlled trial or cohort study compared outcomes of PVR and conservative therapy in adults with rTOF. We selected 10 cohort studies (total 657 patients) reporting secondary outcomes. After PVR, the pooled incidence rate of death was 1% per year (95% confidence interval [CI] 0-1% per year) and the pooled incidence rate of sustained ventricular arrhythmias was 1% per year (95% CI 1%-2% per year). PVR improved symptoms (odds ratio for postoperative New York Heart Association functional class > II 0.08, 95% CI 0.03-0.24). Indexed RV end-diastolic (-61.29 mL/m², -43.64 to -78.94 mL/m²) and end-systolic (-37.20 mL/m², -25.58 to -48.82 mL/m²) volumes decreased after PVR, but RV ejection fraction did not change (0.19%, -2.36% to 2.74%). The effect of PVR on RV volumes remained constant regardless of functional status.

CONCLUSION

Studies comparing PVR and conservative therapy exclusively in adults with rTOF are lacking. After PVR, the incidence rates of death and ventricular tachycardia are both 1 per 100 patient-years. Pooled analyses demonstrated an improved functional status and a reduction in RV volumes.

Porcine Versus Pericardial Pulmonary Valve Replacement in Adults With Prior Congenital Cardiac Surgery: Midterm Outcomes

Background:

Postcongenital heart surgery pulmonary regurgitation requires subsequent pulmonary valve replacement. We sought to compare the outcomes of pulmonary valve replacement after using bioprosthetic valves, porcine versus pericardial bioprosthesis.

Method:

Retrospective single-center study of consecutive pulmonary valve replacement in patients with pulmonary regurgitation following initial congenital cardiac surgery. From 2004 to 2016, 82 adult patients (53 males, 29 females) underwent pulmonary valve replacement at a mean age of 28.7 ± 8 years (range 18-52 years) with a mean time to pulmonary valve replacement of 24 ± 7 years (range 13-43 years). Porcine bioprosthetic valves (group 1, n = 32) and pericardial valves (group 2, n = 50) were used. Cardiac magnetic resonance imaging was performed (n = 54) at a mean of 18 ± 13 months before and 24 ± 21 months after pulmonary valve replacement.

Results:

No significant difference was seen between the groups except that the mean follow-up was longer for group 1 (5.02 ± 2.06 vs 4.08 ± 3.21 years). In-hospital mortality was 1.1%. Follow-up completeness was 100% with no late death. Mean right ventricular end-systolic and end-diastolic volumes reduced significantly in both the groups ( P < .001), whereas right ventricular ejection fraction remained unchanged (group 1, P = .129; group 2, P = .675) . Only the left ventricular end-diastolic volume increased in both the groups, but the increase was significant for group 2 only (group 1, P = .070; group 2, P = .015), whereas the left ventricular end-systolic and ejection fraction remained unchanged in both the groups. There was no reoperation for pulmonary valve replacement. Freedom from intervention was 93.8% (group 1) and 100% (group 2) at eight years after pulmonary valve replacement ( P = .407).

Conclusion:

Midterm outcomes of pulmonary valve replacement in our adult cohort were satisfactory. Both types of bioprosthetic valves performed comparably for eight years and were a good option in adults.

The change of QRS duration after pulmonary valve replacement in patients with repaired tetralogy of Fallot and pulmonary regurgitation

Purpose

This study aimed to analyze changes in QRS duration and cardiothoracic ratio (CTR) following pulmonary valve replacement (PVR) in patients with tetralogy of Fallot (TOF).

Methods

Children and adolescents who had previously undergone total repair for TOF (n=67; median age, 16 years) who required elective PVR for pulmonary regurgitation and/or right ventricular out tract obstruction were included in this study. The QRS duration and CTR were measured pre- and postoperatively and postoperative changes were evaluated.

Results

Following PVR, the CTR significantly decreased (pre-PVR 57.2%±6.2%, post-PVR 53.8%±5.5%, P=0.002). The postoperative QRS duration showed a tendency to decrease (pre-PVR 162.7±26.4 msec, post-PVR 156.4±24.4 msec, P=0.124). QRS duration was greater than 180 msec in 6 patients prior to PVR. Of these, 5 patients showed a decrease in QRS duration following PVR; QRS duration was less than 180 msec in 2 patients, and QRS duration remained greater than 180 msec in 3 patients, including 2 patients with diffuse postoperative right ventricular outflow tract hypokinesis. Six patients had coexisting arrhythmias before PVR; 2 patients, atrial tachycardia; 3 patients, premature ventricular contraction; and 1 patient, premature atrial contraction. None of the patients presented with arrhythmia following PVR.

Conclusion

The CTR and QRS duration reduced following PVR. However, QRS duration may not decrease below 180 msec after PVR, particularly in patients with right ventricular outflow tract hypokinesis. The CTR and ECG may provide additional clinical information on changes in right ventricular volume and/or pressure in these patients.

Perioperative Factors Influence the Long-Term Outcomes of Children and Adolescents with Repaired Tetralogy of Fallot

Tetralogy of Fallot (TOF) often carries long-term seqüelae following surgical intervention. We hypothesized that early perioperative factors are associated with long-term adverse right ventricular (RV) remodeling, diminished exercise capacity, and increased morbidity. We conducted a retrospective cohort study of patients operated for TOF that underwent cardiac magnetic resonance imaging study (CMR), exercise stress test (EST), and detailed review of past medical history. Outcome variables included measures of RV size, and function, maximal work rate, and oxygen consumption, and interim hospitalizations, surgeries, and catheterizations. Thirty-nine subjects were included. Age at surgical repair was 0.3 ± 0.3 years and age at testing was 9.7 ± 1.4 years. On CMR, there was borderline RV dilation with moderate pulmonary insufficiency (PI) [RF 32% (8; 43)] and normal RV ejection fraction [60% (55; 67)]. On EST, there was low percent-predicted maximal oxygen consumption (77 ± 20%), and percent-predicted maximal work rate (84 ± 23%). On multivariable analysis, mechanical ventilation and Blalock-Taussig (BT) shunt prior to complete surgical repair were associated with the number of future hospitalizations. Duration of cardiopulmonary bypass and prior BT shunt were associated with future catheterizations. Prior BT shunt was a predictor of worse RVEF, while duration of mechanical ventilation and use of transannular patch were predictors of worse PI. Longer duration of mechanical ventilation (or LOS) was associated with worse maximal work rate. Surgical and perioperative factors may portend long-term RV remodeling and outcome in TOF. Further studies are warranted to explore these associations and potential underlying mechanisms.

Mid-term outcomes of mechanical pulmonary valve replacement: a single-institutional experience of 396 patients

OBJECTIVES

Previous small-sized studies have demonstrated the safety and efficacy of mechanical pulmonary valve replacement (mPVR) in patients with congenital heart disease; however, the predictors of major complications and reoperation remained unclear.

METHODS

In a retrospective study, we reported the mid-term outcomes of a large-scaled series of patients, 396 patients, with congenital heart diseases who underwent mPVR in a single institution.

RESULTS

The patients' mean age at mPVR was 24.3 ± 9 years (4-58 years). Most patients (84.3%) underwent tetralogy of Fallot total correction. The median of follow-up was 36 months (24-49 months). Prosthetic valve malfunction caused by thrombosis or pannus formation developed in 12.1% of patients during follow-up period. Reoperation was performed in 7 cases with pannus formation and 6 cases with mechanical valve thrombosis. Freedom from reoperation at 1, 5, and 10 years was 99%, 97%, and 96%, respectively. Neither early nor mid-term mortalities were detected. Cox regression models showed that male gender and smaller valve size increased the risk of prosthetic valve failure. The age at mPVR, interval between congenital heart defect repair and mPVR, and concomitant procedures predicted reoperation. In multivariate analysis, younger age and the interval between first operation and mPVR predicted reoperation either.

CONCLUSIONS

The success rate of mPVR is excellent in mid-term follow-up. Younger age, longer interval between the repair of congenital defect and mPVR, and cooperation increased reoperation risk. However, strict adherence to life-long anticoagulation regimen and patient selection are of great importance for the implementation of mPVR.

Transcatheter Versus Surgical Pulmonary Valve Replacement in Repaired Tetralogy of Fallot

Transcatheter pulmonary valve replacement (TC-PVR) is an alternative to surgical PVR (S-PVR) in repaired Tetralogy of Fallot (TOF). The purpose of this study is to compare in-hospital outcomes, hospital costs, and projected 5-year total costs of S-PVR to TC-PVR in patients with repaired TOF. We performed a multicenter, retrospective cohort study of children and adults with TOF ≥ 8 years of age who underwent PVR from January 1, 2010 to December 31, 2016 at 46 centers contributing to the Pediatric Health Information Systems database. Baseline characteristics, in-hospital outcomes, and costs were compared between the two groups. Projected 5-year costs were calculated by combining cost data with published reintervention rates. A total of 194 TC-PVR and 1,072 S-PVR were performed. The baseline characteristics of the TC-PVR and S-PVR groups were not significantly different with the exception of greater age in the TC-PVR group (median age of 17 years vs 15 years, p value <0.001). Discharge mortality, hospital charges and estimated cost, surgical complication rates, and acute kidney failure were not significantly different between the groups. Intensive care unit use, intensive care unit length of stay (LOS), mechanical ventilation use, extracorporeal membrane oxygenation use, and total LOS were lower with TC-PVR than S-PVR. Projected 5-year costs were greater with TC-PVR compared with S-PVR ($64,762 vs $56,536) due to the cost of the transcatheter pulmonary valve and higher reintervention rates. In conclusion, despite longer LOS and greater in-hospital resource utilization for patients with TOF who underwent S-PVR compared with TC-PVR, mortality, and in-hospital costs are the same, and projected 5-year costs are less.

Impact of surgical pulmonary valve replacement on ventricular strain and synchrony in patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance feature tracking study

BACKGROUND

In patients with repaired tetralogy of Fallot (TOF), a better understanding of the impact of surgical pulmonary valve replacement (PVR) on ventricular mechanics may lead to improved indications and outcomes. Therefore, we used cardiovascular magnetic resonance (CMR) feature tracking analysis to quantify ventricular strain and synchrony in repaired TOF patients before and after PVR.

METHODS

Thirty-six repaired TOF patients (median age 22.4 years) prospectively underwent CMR a mean of 4.5 ± 3.8 months before PVR surgery and 7.3 ± 2.1 months after PVR surgery. Feature tracking analysis on cine steady-state free precession images was used to measure right ventricular (RV) and left ventricular (LV) circumferential strain from short-axis views at basal, mid-ventricular, and apical levels; and longitudinal strain from 4-chamber views. Intraventricular synchrony was quantified using the maximum difference in time-to-peak strain, the standard deviation of the time-to-peak, and cross correlation delay (CCD) metrics; interventricular synchrony was assessed using the CCD metric.

RESULTS

Following PVR, RV end-diastolic volume, end-systolic volume, and ejection fraction declined, and LV end-diastolic volume and end-systolic volume both increased with no significant change in the LV ejection fraction. LV global basal and apical circumferential strains, and basal synchrony improved. RV global circumferential and longitudinal strains were unchanged, and there was a varied impact on synchrony across the locations. Interventricular synchrony worsened at the midventricular level but was unchanged at the base and apex, and on 4-chamber views.

CONCLUSIONS

Surgical PVR in repaired TOF patients led to improved LV global strain and no change in RV global strain. LV and RV synchrony parameters improved or were unchanged, and interventricular synchrony worsened at the midventricular level.

Impact of Percutaneous Pulmonary Valve Implantation on the Timing of Reintervention for Right Ventricular Outflow Tract Dysfunction

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. Early surgical repair has dramatically improved the outcome of this condition. However, despite the success of contemporary approaches with early complete repair, these are far from being curative and late complications are frequent. The most common complication is right ventricle outflow tract (RVOT) dysfunction, affecting most patients in the form of pulmonary regurgitation, pulmonary stenosis, or both, and can lead to development of symptoms of exercise intolerance, arrhythmias, and sudden cardiac death. Optimal timing of restoration of RVOT functionality in asymptomatic patients with RVOT dysfunction after TOF repair is still a matter of debate. Percutaneous pulmonary valve implantation, introduced almost 2 decades ago, has become a major game-changer in the treatment of RVOT dysfunction. In this article we review the pathophysiology, the current indications, and treatment options for RVOT dysfunction in patients after TOF repair with a focus on the role of percutaneous pulmonary valve implantation in the therapeutic approach to these patients.

Immediate and Midterm Cardiac Remodeling After Surgical Pulmonary Valve Replacement in Adults With Repaired Tetralogy of Fallot: A Prospective Cardiovascular Magnetic Resonance and Clinical Study

BACKGROUND

Pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot provides symptomatic benefit and right ventricular (RV) volume reduction. However, data on the rate of ventricular structural and functional adaptation are scarce. We aimed to assess immediate and midterm post-PVR changes and predictors of reverse remoeling.

METHODS

Fifty-seven patients with repaired tetralogy of Fallot (age ≥16 y; mean age, 35.8±10.1 y; 38 male) undergoing PVR were prospectively recruited for cardiovascular magnetic resonance performed before PVR (pPVR), immediately after PVR (median, 6 d), and midterm after PVR (mPVR; median, 3 y).

RESULTS

There were immediate and midterm reductions in indexed RV end-diastolic volumes and RV end-systolic volumes (RVESVi) (indexed RV end-diastolic volume pPVR versus immediately after PVR versus mPVR, 156.1±41.9 versus 104.9±28.4 versus 104.2±34.4 mL/m²; RVESVi pPVR versus immediately after PVR versus mPVR, 74.9±26.2 versus 57.4±22.7 versus 50.5±21.7 mL/m²; P<0.01). Normal postoperative diastolic and systolic RV volumes (the primary end point) achieved in 70% of patients were predicted by a preoperative indexed RV end-diastolic volume ≤158 mL/m² and RVESVi ≤82 mL/m². RVESVi showed a progressive decrease from baseline to immediate to midterm follow-up, indicating ongoing intrinsic RV functional improvement after PVR. Left ventricular ejection fraction improved (pPVR versus mPVR, 59.4±7.6% versus 61.9±6.8%; P<0.01), and right atrial reverse remodeling occurred (pPVR versus mPVR, 15.2±3.4 versus 13.8±3.6 cm²/m²; P<0.01). Larger preoperative RV outflow tract scar was associated with a smaller improvement in post-PVR RV/left ventricular ejection fraction. RV ejection fraction and peak oxygen uptake predicted mortality (P=0.03) over a median of 9.5 years of follow-up.

CONCLUSIONS

Significant right heart structural reverse remodeling takes place immediately after PVR, followed by a continuing process of further biological remodeling manifested by further reduction in RVESVi. PVR before RVESVi reaches 82 mL/m² confers optimal chances of normalization of RV function.

Pulmonic Valve Disease: Review of Pathology and Current Treatment Options

PURPOSE OF REVIEW

Our review is intended to provide readers with an overview of disease processes involving the pulmonic valve, highlighting recent outcome studies and guideline-based recommendations; with focus on the two most common interventions for treating pulmonic valve disease, balloon pulmonary valvuloplasty and pulmonic valve replacement.

RECENT FINDINGS

The main long-term sequelae of balloon pulmonary valvuloplasty, the gold standard treatment for pulmonic stenosis, remain pulmonic regurgitation and valvular restenosis. The balloon:annulus ratio is a major contributor to both, with high ratios resulting in greater degrees of regurgitation, and small ratios increasing risk for restenosis. Recent studies suggest that a ratio of approximately 1.2 may provide the most optimal results. Pulmonic valve replacement is currently the procedure of choice for patients with severe pulmonic regurgitation and hemodynamic sequelae or symptoms, yet it remains uncertain how it impacts long-term survival. Transcatheter pulmonic valve replacement is a rapidly evolving field and recent outcome studies suggest short and mid-term results at least equivalent to surgery. The Melody valve® was FDA approved for failing pulmonary surgical conduits in 2010 and for failing bioprosthetic surgical pulmonic valves in 2017 and has been extensively studied, whereas the Sapien XT valve®, offering larger diameters, was approved for failing pulmonary conduits in 2016 and has been less extensively studied. Patients with pulmonic valve disease deserve lifelong surveillance for complications. Transcatheter pulmonic valve replacement is a novel and attractive therapeutic option, but is currently only FDA approved for patients with failing pulmonary conduits or dysfunctional surgical bioprosthetic valves. New advances will undoubtedly increase the utilization of this rapidly expanding technology.

Earlier Pulmonary Valve Replacement in Down Syndrome Patients Following Tetralogy of Fallot Repair

The association between Down syndrome and pulmonary hypertension could contribute to more severe pulmonary regurgitation after tetralogy of Fallot repair and possibly earlier pulmonary valve replacement. We compared cardiac magnetic resonance measures of pulmonary regurgitation and right ventricular dilation as well as timing of pulmonary valve replacement between those with and without Down syndrome after tetralogy of Fallot repair. Review of our surgical database from 2000 to 2015 identified patients with tetralogy of Fallot with pulmonary stenosis. Those with Down syndrome were compared to those without. The primary outcome of interest was time from repair to pulmonary valve replacement. Secondary outcomes included pulmonary regurgitation and indexed right ventricular volume on cardiac magnetic resonance imaging. The cohort of 284 patients included 35 (12%) with Down syndrome. Transannular patch repair was performed in 210 (74%). Down syndrome showed greater degree of pulmonary regurgitation (55 ± 14 vs. 37 ± 16%, p = 0.01) without a significantly greater rate of right ventricular dilation (p = 0.09). In multivariable analysis, Down syndrome (HR 2.3, 95% CI 1.2-4.5, p = 0.02) and transannular patch repair (HR 5.5, 95% CI 1.7-17.6, p = 0.004) were significant risk factors for valve replacement. Those with Down syndrome had significantly lower freedom from valve replacement (p = 0.03). Down syndrome is associated with an increased degree of pulmonary regurgitation and earlier pulmonary valve replacement after tetralogy of Fallot repair. These patients require earlier assessment by cardiac magnetic resonance imaging to determine timing of pulmonary valve replacement and evaluation for and treatment of preventable causes of pulmonary hypertension.

The Role of Cardiopulmonary Exercise Testing for Decision Making in Patients with Repaired Tetralogy of Fallot

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. As a result of the surgical strategies employed at the time of initial repair, chronic pulmonary regurgitation (PR) is prevalent in this population. Despite sustained research efforts, patient selection and timing of pulmonary valve replacement (PVR) to address PR in young asymptomatic patients with repaired tetralogy of Fallot (rToF) remain a fundamental but as yet unanswered question in the field of congenital heart disease. The ability of the heart to compensate for the chronic volume overload imposed by PR is critical in the evaluation of the risks and benefits of PVR. The difficulty in clarifying the functional impact of PR on the cardiovascular capacity may be in part responsible for the uncertainty surrounding the timing of PVR. Cardiopulmonary exercise testing (CPET) may be used to assess abnormal cardiovascular response to increased physiologic demands. However, its use as a tool for risk stratification in asymptomatic adolescents and young adults with rToF is still ill-defined. In this paper, we review the role of CPET as a potentially valuable adjunct to current risk stratification strategies with a focus on asymptomatic rToF adolescents and young adults being considered for PVR. The role of maximal and submaximal exercise measurements to identify young patients with a decreased or borderline low peak VO₂ resulting from impaired ventricular function is explored. Current knowledge gaps and research perspectives are highlighted.

Pulmonary Valve Procedures Late After Repair of Tetralogy of Fallot: Current Perspectives and Contemporary Approaches to Management

Few topics in adult congenital heart disease have approached the level of scrutiny bestowed on pulmonary valve replacement (PVR) strategies late after tetralogy of Fallot (TOF) repair. Despite the successes of primary surgery for TOF, there is a growing group of adults with residual right ventricular outflow tract and pulmonary valve dysfunction. Patients with residual chronic pulmonic regurgitation as a consequence of earlier surgery can later develop symptoms of exercise intolerance and complications including heart failure, tachyarrhythmias, and sudden cardiac death. Optimal timing of PVR has sparked debate, which has catalyzed increasing research efforts over the past decade. Although performance of PVR in the absence of symptoms is currently on the basis of the rationale that achievement of complete reverse remodelling is highly desirable, whether this approach results in improvement in patient outcomes in the long-term has yet to be shown. Surgical PVR and percutaneous pulmonary valve intervention are different techniques with specific advantages and disadvantages that require careful consideration for each individual patient, alongside the need for requisite reinterventions over the course of a patient's lifetime. Criteria pertaining to referral strategies are ever being refined as newer technologies for percutaneous therapies continue to evolve. In this article we review the literature surrounding the indications for, the optimal timing of, and the approaches to pulmonary valve procedures in adults with previously repaired TOF.

[Pulmonary revalvulation and rhythmologenic risks in patients with repaired tetralogy of Fallot]

Tetralogy of Fallot is a frequent congenital heart disease that has been repaired since the mid-1950s. The follow-up after repair is good despite a persistent risk of sudden death. The risk factors in long-term follow-up are advanced age at repair, hemodynamic status of the right ventricle, QRS duration≥180ms, left ventricular dysfunction, and existence of sustained or not ventricular tachycardia. In the presence of significant pulmonary regurgitation, it is necessary to perform revalvulation either by classic surgery or cardiac catheterization. To correct the risk of ventricular arrhythmia, some have proposed radiofrequency ablation of critical isthmus, or cryo-application during surgery. However, the use of implantable cardioverter defibrillator is another therapeutic option that is more and more employed as secondary or primary prevention in patients at risk of sudden death.

Ventricular Arrhythmias in Adult Congenital Heart Disease: Mechanisms, Diagnosis, and Clinical Aspects

The risk of ventricular arrhythmias in the adult congenital heart disease population increases with age. The mechanism, type, and frequency vary depending on the complexity of the defect, whether it has been repaired, and the type and timing of repair. Risk stratification for sudden death in patients with congenital heart disease is often challenging. Current recommendations provide a useful guide for management of these patients and risk stratification continues to evolve. Internal cardiac defibrillator implantation is often challenging due to limited transvenous access, often resulting in the need for epicardial or subcutaneous devices.

[The successful saga of percutaneous pulmonary valvulation in congenital heart diseases]

With new surgical techniques, more and more complex congenital heart defects are treated requiring sometimes right ventricle to pulmonary artery conduit implantation. In order to extend RV to PA conduit lifespan, 15 years ago a valved stent was developed. The implantation technique was progressively standardized to decrease risks of procedural complications. Medium and long-term hemodynamic results of the stent were so good that indications were broadened to native or complex right ventricular outflow tracts. Currently, 2 types of stents are implanted routinely: the Melody valve^® (Medtronic, Minneapolis, USA) and the Sapien^® valve (Edwards, Lifesciences, Irvine, USA). Other devices are evaluated in trials: thanks to their diabolo shape, implantation is feasible in large outflows tracts. The main source of worries is infective endocarditis. Numerous studies are conducted in order to identify risks factors, prevention and optimal treatment of this complication. In the near future, new devices and new implantation strategies will make this technology available for a larger number of patients.

Adults with repaired tetralogy: low mortality but high morbidity up to middle age

Objective

Survival of patients with repaired tetralogy of Fallot (rToF) into young adulthood is very good. Concerns exist, however, over long-term morbidity and mortality as these subjects reach middle age. We aimed to assess survival and the prevalence of complications in patients with rToF seen in our Adult Congenital Heart Disease (ACHD) service.

Methods

One hundred and sixty-eight consecutive patients with ‘simple rToF’, aged over 16 years, followed up at our tertiary-level ACHD service in Sydney, Australia since 2000, were included. We documented mortality and analysed the prospectively defined composite end points of (a) ‘Serious adverse events’, including death, heart failure hospitalisation and/or documented ventricular arrhythmia and (b) ‘Adverse events’ inclusive of the above and endocarditis, atrial arrhythmia, defibrillator and/or pacemaker implantation.

Results

Mean age at the last follow-up was 34±12 years, and 55% were men. There were 10 (6%) deaths, and 26 patients (16%) experienced a ‘serious adverse event’. Fifty-one patients (30%) experienced an ‘adverse event’ and 29 patients had atrial arrhythmias. One hundred and one (61%) patients had at least one pulmonary valve replacement. By age 40 years, 93% were free of serious adverse events, and 83% were free of any adverse event. By age 50 years, only 56% had not had an adverse event. Older age and history of atrial arrhythmia were predictive of serious adverse events.

Conclusion

Survival into mid-adulthood in patients with rToF is very good; however, a substantial number of survivors have adverse events by the age of 50 years.

Ventricular tachycardia in repaired congenital heart disease

Ventricular arrhythmias are an important cause of late morbidity and sudden cardiac death in the growing population of adults with repaired congenital heart disease. Risk stratification remains challenging because of the heterogeneity of the malformations and the surgical approaches. Therapeutic interventions depend on the type of ventricular arrhythmia, which can be polymorphic ventricular tachycardia (VT) or ventricular fibrillation in patients without ventricular scars, but also potentially fatal monomorphic reentrant VTs, typical for patients with ventricular scars or obstacles. Advances in surgical techniques have improved survival and have important implications for the arrhythmia substrates and prognosis. Over the past few decades, progress has been made to determine the anatomical basis for monomorphic VT in patients with ventricular surgical scars and patch material. These substrates can be currently identified and targeted during sinus rhythm by radiofrequency catheter or surgical ablation without the need for VT induction. The review provides an update on the evolving surgical approaches, the changing VA substrates, and the potential consequences for individualized risk assessment and tailored treatment.