Pulmonary Valve Replacement Timing Following Initial Tetralogy of Fallot Repair: A Systematic Review

Pulmonary valve replacement (PVR) is a critical aspect of surgical management for patients with tetralogy of Fallot (ToF). Determining an optimal timeframe for intervention is imperative, as it directly impacts long-term outcomes and the risk of complications in ToF patients. Ventriculotomy with the transannular patch is currently indicated for right ventricular outflow tract obstruction, but the patch itself can lead to pulmonary regurgitation (PR), dyspnea, and cyanosis, among other complications. This investigation seeks to establish an evidence-based timeline to enhance the overall quality of care for individuals with this congenital heart condition. From 2002 to 2022, 21,935 articles regarding the PVR timing for ToF were examined and filtered. The publications were screened using PRISMA guidelines, and 32 studies were included for analysis and review. Among the studies, PVR was strongly indicated for patients who had developed severe PR, especially in asymptomatic patients and those experiencing fatigue and exercise intolerance. Severe PR was associated with arrhythmias such as right bundle branch block, atrioventricular block, and prolonged QRS intervals, in which male sex and high right ventricular end-diastolic volume (RVEDV) were significant predictors of long preoperative QRS duration. Most physicians found RVEDV necessary for making surgical referrals despite a lack of correlation between PR severity and RVEDV or indexed right ventricular end-systolic volume (RVESVi). However, asymptomatic ToF patients with preoperative RVESVi benefited from PVR. Except for some variations in QRS intervals among studies, arrhythmias tended to persist post-op, yet NYHA functional class and RV size improved significantly following PVR. Older age at PVR was found to be associated with adverse cardiac events, whereas early PVR presented with appropriately short QRS intervals. Cardiac function tended to be significantly worse in patients undergoing late PVR versus early PVR, with timelines ranging from one to three decades following initial ToF repair. Choosing the best timeline for PVR largely depends on the patient's baseline cardiopulmonary presentation, and additional quantitative deformation analysis can help predict an appropriate timeline for ToF patients.

Pulmonary Allograft Versus Medtronic Freestyle Valve in Surgical Pulmonary Valve Replacement for Adults Following Correction of Tetralogy of Fallot or Its Variants

Background:

Following corrective surgery in infancy/childhood for tetralogy of Fallot (TOF) or its variants, patients may eventually require pulmonary valve replacement (PVR). Debate remains over which valve is best. We compared outcomes of the Medtronic Freestyle valve with that of the pulmonary allograft valve following PVR.

Methods:

A retrospective study was undertaken from a single surgical practice of adult patients undergoing elective PVR between April 1993 and March 2017. The choice of valve was at the surgeon’s discretion. There was a trend toward the almost exclusive use of the more readily available Medtronic Freestyle valve since 2008.

Results:

One hundred fifty consecutive patients undergoing 152 elective PVRs were reviewed. Their mean age was 33.8 years. Ninety-four patients had a Medtronic Freestyle valve, while 58 had a pulmonary allograft valve. There were no operative or 30-day mortality. The freedom from reintervention at 5 and 10 years was 98% and 98% for the pulmonary allograft and 99% and 89% for the Medtronic Freestyle. There was no significant difference in the rate of reintervention, though this was colored by higher pulmonary gradients across the Medtronic Freestyle despite its shorter follow-up.

Conclusions:

Pulmonary valve replacement following previous surgical repair of TOF or its variants was found to be safe with no significant differences in mortality or reintervention between either valve. Although the Medtronic Freestyle valve had a greater tendency toward pulmonary stenosis, additional follow-up is needed to further document its long-term outcomes.

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.

Sustained Improvement in Right Ventricular Chamber Dimensions 10 Years Following Xenograft Pulmonary Valve Replacement

Background:

The goals following pulmonary valve replacement (PVR) are to optimize right ventricular hemodynamics and minimize the need for subsequent reoperations on the right ventricular outflow tract. We hypothesized PVR using a xenograft valved conduit would result in superior freedom from reoperation with sustained improvement in right ventricular chamber dimensions.

Methods:

Xenograft valved conduits placed in patients aged >16 years were reviewed from 2000 to 2010 to allow for a 5-year minimum follow-up. Preoperative, one-year, and the most recent echocardiograms quantified right ventricular chamber dimensions, corresponding Z scores, and prosthetic valve function. Magnetic resonance imaging (MRI) studies compared preoperative and follow-up right ventricular volumes.

Results:

A total of 100 patients underwent PVR at 24 (19-34) years. Freedom from reintervention was 100% at 10 years. At most recent follow-up, only one patient had greater than mild pulmonary insufficiency. The one-year (17.3 ± 7.2 mm Hg; P < .01) and most recent follow-up (18.6 ± 9.8 mm Hg; P < .01) Doppler-derived right ventricular outflow tract gradients remained significantly lower than preoperative measurements (36.7 ± 27.0 mm Hg). Similarly, right ventricular basal diameter, basal longitudinal diameter, and the corresponding Z scores remained lower at one year and follow-up from preoperative measurements. From 34 MRI studies, the right ventricular end-diastolic indexed volume (161.7 ± 58.5 vs 102.9 ± 38.3; P < .01) and pulmonary regurgitant fraction (38.0% ± 15.9% vs 0.8% ± 3.3%; P < .01) were significantly lower at 7.1 ± 3.4 years compared to the preoperative levels.

Conclusion:

Use of a xenograft valved conduit for PVR results in excellent freedom from reoperation with sustained improvement in right ventricular dimensions at an intermediate-term follow-up.

Emerging Research Directions in Adult Congenital Heart Disease: A Report From an NHLBI/ACHA Working Group

Congenital heart disease (CHD) is the most common birth defect, affecting about 0.8% of live births. Advances in recent decades have allowed >85% of children with CHD to survive to adulthood, creating a growing population of adults with CHD. Little information exists regarding survival, demographics, late outcomes, and comorbidities in this emerging group, and multiple barriers impede research in adult CHD. The National Heart, Lung, and Blood Institute and the Adult Congenital Heart Association convened a multidisciplinary working group to identify high-impact research questions in adult CHD. This report summarizes the meeting discussions in the broad areas of CHD-related heart failure, vascular disease, and multisystem complications. High-priority subtopics identified included heart failure in tetralogy of Fallot, mechanical circulatory support/transplantation, sudden cardiac death, vascular outcomes in coarctation of the aorta, late outcomes in single-ventricle disease, cognitive and psychiatric issues, and pregnancy.

Risk Factors for Prosthetic Pulmonary Valve Failure in Patients With Congenital Heart Disease

The incidence and risk factors for prosthetic pulmonary valve failure (PPVF) should be considered when determining optimal timing for pulmonary valve replacement (PVR) in asymptomatic patients with congenital heart disease (CHD). The cumulative freedom for reintervention due to PPVF after 146 PVR in 114 patients with CHD was analyzed. Six potential risk factors (underlying cardiac defect, history of palliative procedures, number of previous cardiac interventions, hemodynamic indication for PVR, type of intervention, and age at intervention) were analyzed using Cox proportional hazard modeling. Receiver operating characteristic (ROC) curves were used for discrimination. Internal validation in patients with tetralogy of Fallot was also performed. Median age at intervention was 23 years. There were 60 reinterventions due to PPVF (41%). Median event-free survival was 14 years (95% confidence interval [CI] 12 to 16 years). The only independent risk factor was the age at intervention (hazard ratio [HR] 0.93, 95% CI 0.90 to 0.97; p = 0.001; area under the ROC curve 0.95, 95% CI 0.92 to 0.98; p <0.001). The best cut-off point was 20.5 years. Freedom from reintervention for PPVF 15 years after surgery was 70% when it was performed at age >20.5 years compared with 33% when age at intervention was <20.5 years (p = 0.004). Internal validation in 102 PVR in patient cohort with tetralogy of Fallot (ROC area 0.98, 95% CI 0.96 to 1.0; p <0.001) was excellent. In conclusion, age at intervention is the main risk factor of reintervention for PPVF. The risk of reintervention is 2-fold when PVR is performed before the age of 20.5 years.

Trends in pulmonary valve replacement in children and adults with tetralogy of fallot

Operative correction of tetralogy of Fallot frequently results in pulmonary insufficiency and chronic volume overload, which have been linked to increased risk for adverse outcomes. No consensus recommendations for the timing of pulmonary valve replacement (PVR) exist. The aim of this study was to examine the pattern of PVR in the United States from 2004 to 2012. The Pediatric Health Information Systems database was used to perform an observational study of children and adults ≥10 years of age with diagnoses of tetralogy of Fallot who underwent PVR at 35 centers in the United States from 2004 and 2012, to assess the rate of PVR and the age at which is performed. Mixed-effects multivariate regression was used to account for patient-level covariates and center-level covariance. Additional analyses assessed for trends in cost, hospital length of stay (LOS), intensive care unit LOS, and in-hospital mortality over the study period. In total, 799 subjects at 35 centers underwent PVR over the study period. The number of PVRs performed per year increased significantly over the study period. There was significant between-center heterogeneity in age at PVR (p <0.001). Age at PVR, intensive care unit LOS, hospital LOS, and cost did not change over the study period. In conclusion, PVR in patients with tetralogy of Fallot is being performed more frequently, without an accompanying change in the age at PVR or other measurable outcomes. There is significant variability in the age at which PVR is performed among centers across the United States. This highlights the need for additional research guiding the optimal timing of PVR.

Pulmonic regurgitation and management challenges in the adult with tetralogy of fallot

OPINION STATEMENT

Patients with tetralogy of Fallot (TOF) are living longer than ever because of advances in surgery in childhood since the 1950s. However, surgery in childhood is not a cure and remains only a palliative procedure because almost all patients will require further intervention throughout life. The most common intervention required in adulthood is pulmonary valve replacement (PVR) because of residual pulmonary regurgitation leading to right ventricular dilation and eventual dysfunction. The most appropriate timing for PVR remains difficult to determine and is based on many factors. Our practice is to weigh not only objective factors such as right ventricular size and function but also careful objective assessment of the patient's current quality of life and functional status.

Clinical Outcomes of Surgical Pulmonary Valve Replacement After Repair of Tetralogy of Fallot and Potential Prognostic Value of Preoperative Cardiopulmonary Exercise Testing

Background—

Indications for surgical pulmonary valve replacement (PVR) after repair of tetralogy of Fallot have recently been broadened to include asymptomatic patients.

Methods and Results—

The outcomes of PVR in adults after repair of tetralogy of Fallot at a single tertiary center were retrospectively studied. Preoperative cardiopulmonary exercise testing was included. Mortality was the primary outcome measure. In total, 221 PVRs were performed in 220 patients (130 male patients; median age, 32 years; range, 16–64 years). Homografts were used in 117 patients, xenografts in 103 patients, and a mechanical valve in 1 patient. Early (30-day) mortality was 2%. Overall survival was 97% at 1 year, 96% at 3 years, and 92% at 10 years. Survival after PVR in the later era (2005–2010; n=156) was significantly better compared with survival in the earlier era (1993–2004; n=65; 99% versus 94% at 1 year and 98% versus 92% at 3 years, respectively; P =0.019). Earlier era patients were more symptomatic preoperatively ( P =0.036) with a lower preoperative peak oxygen consumption (peak o 2 ; P <0.001). Freedom from redo surgical or transcatheter PVR was 98% at 5 years and 96% at 10 years for the whole cohort. Peak o 2 , E/CO2 slope (ratio of minute ventilation to carbon dioxide production), and heart rate reserve during cardiopulmonary exercise testing predicted risk of early mortality when analyzed with logistic regression analysis; peak o 2 emerged as the strongest predictor on multivariable analysis (odds ratio, 0.65 per 1 mL·kg −1 ·min −1 ; P =0.041).

Conclusions—

PVR after repair of tetralogy of Fallot has a low and improving mortality, with a low need for reintervention. Preoperative cardiopulmonary exercise testing predicts surgical outcome and should therefore be included in the routine assessment of these patients.

Clinical research priorities in adult congenital heart disease

BACKGROUND

Adult congenital heart disease (ACHD) clinicians are hampered by the paucity of data to inform clinical decision-making. The objective of this study was to identify priorities for clinical research in ACHD.

METHODS

A list of 45 research questions was developed by the Alliance for Adult Research in Congenital Cardiology (AARCC), compiled into a survey, and administered to ACHD providers. Patient input was sought via the Adult Congenital Heart Association at community meetings and online forums. The 25 top questions were sent to ACHD providers worldwide via an online survey. Each question was ranked based on perceived priority and weighted based on time spent in ACHD care. The top 10 topics identified are presented and discussed.

RESULTS

The final online survey yielded 139 responses. Top priority questions related to tetralogy of Fallot (timing of pulmonary valve replacement and criteria for primary prevention ICDs), patients with systemic right ventricles (determining the optimal echocardiographic techniques for measuring right ventricular function, and indications for tricuspid valve replacement and primary prevention ICDs), and single ventricle/Fontan patients (role of pulmonary vasodilators, optimal anticoagulation, medical therapy for preservation of ventricular function, treatment for protein losing enteropathy). In addition, establishing criteria to refer ACHD patients for cardiac transplantation was deemed a priority.

CONCLUSIONS

The ACHD field is in need of prospective research to address fundamental clinical questions. It is hoped that this methodical consultation process will inform researchers and funding organizations about clinical research topics deemed to be of high priority.

Midgestation fetal pulmonary annulus size is predictive of outcome in tetralogy of fallot

BACKGROUND

Surgical management of tetralogy of Fallot (TOF) is increasingly moving toward valve-sparing approaches rather than transannular patch (TAP). We evaluate whether fetal pulmonary valve (PV) size is predictive of postnatal course and surgical approach in TOF.

METHODS

In this retrospective study, fetal and postnatal demographic, clinical, and echocardiographic data on 66 patients diagnosed prenatally with TOF were collected. We compared those with midgestation PV z-score > -3.5 to those with z-score ≤-3.5. We analyzed fetal and postnatal PV size and growth and outcomes between groups

RESULTS

Gestational age at first fetal echo was 23 weeks (range 18-28). PV diameter and z-score on midgestation echo were 3.5 mm (1.3-6.0) and -2.8 (-0.5 to -6.0) respectively. Patients with PV z-score ≤ -3.5 on first fetal echo had smaller PV diameter (4.5 vs. 5.0 mm, P = .047) and PV z-score (-3.8 vs. -2.8, P < .001) in late gestation and at time of surgery (6.0 mm vs. 7.0 mm, P = .01; z-score = -2.9 vs. -1.7, P = .007). Similarly, those with smaller fetal PV z-score had smaller main and branch pulmonary arteries at time of surgery. PV growth rate over gestation was similar between groups, while after-birth PV growth rate was lower in those with smaller PV (0 mm/month vs. 0.6 mm/month, P = .002). Those with smaller pulmonary valve were more likely to be cyanotic (P = .05), to undergo surgery at <1 month (P < .01), and to have a TAP repair (P = .01). Among patients undergoing valve-sparing repair, those with smaller PV underwent more reinterventions for residual valvar PS (P < .01).

CONCLUSION

Midgestation fetal PV size is predictive of postnatal PV and PA size in TOF. Midgestation PV size has implications for timing and type of surgical management as well as for need for reintervention in valve-sparing repair patients and is therefore important to consider in prenatal counseling for TOF fetuses.

Effect of ventricular size and function on exercise performance and the electrocardiogram in repaired tetralogy of Fallot with pure pulmonary regurgitation

Background:

In repaired tetralogy of Fallot (TOF), exercise test parameters like peak oxygen uptake and ventilatory efficiency predict mortality. Studies have also suggested cardiac magnetic resonance (CMR)-derived right ventricular (RV) size threshold values for pulmonary valve replacement in repaired TOF. However, effects of proposed RV size on exercise capacity and morbidity are not known.

Methods:

The relationship between CMR-derived ventricular size, function, and pulmonary regurgitation (PR) and NYHA class, exercise performance, and electrocardiogram (ECG) was studied in patients of repaired TOF with pure PR in a retrospective review of records.

Results:

46 patients (22 females), mean age 14 years (8–30.8), were studied. There was no relationship between CMR-derived ventricular size, function, or PR and exercise test parameters, or NYHA class. RV end systolic and end diastolic volume correlated positively with the degree of PR. QRS duration on ECG correlated positively with RV end-diastolic volume (P < 0.01, r² = 0.34) and PR (P < 0.01, r² = 0.52).

Conclusions:

In repaired TOF and pure PR, there is no correlation between ventricular size or function and exercise performance. RV size increases with increasing PR. Timing of pulmonary valve replacement in TOF with pure PR needs further prospective evaluation for its effect on morbidity and mortality.

Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support

Surgical management of tetralogy of Fallot (TOF) results in anatomic and functional abnormalities in the majority of patients. Although right ventricular volume load due to severe pulmonary regurgitation can be tolerated for many years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume load is not eliminated or reduced by pulmonary valve replacement the dysfunction might be irreversible. Cardiovascular magnetic resonance (CMR) has evolved during the last 2 decades as the reference standard imaging modality to assess the anatomic and functional sequelae in patients with repaired TOF. This article reviews the pathophysiology of chronic right ventricular volume load after TOF repair and the risks and benefits of pulmonary valve replacement. The CMR techniques used to comprehensively evaluate the patient with repaired TOF are reviewed and the role of CMR in supporting clinical decisions regarding pulmonary valve replacement is discussed.

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

The present meta-analysis aimed to determine the outcomes and effect on right ventricular (RV) function of surgical pulmonary valve replacement (PVR) in patients after repair of tetralogy of Fallot. The reported outcomes of surgical PVR in children and adults after tetralogy of Fallot repair were from relatively small observational studies. The PubMed database was searched from its inception to April 2009. Observational studies reporting on the following outcomes measures after surgical PVR were reviewed: early and late all-cause mortalities, the redo-PVR rate, and changes in the indexed RV volumes, ejection fraction, and QRS duration after PVR. Of the 305 citations screened, 15 met the criteria and were analyzed. The pooled early mortality rate (n = 595) was 2.1% (95% confidence interval [CI] 1.1% to 4.0%). The late mortality rate was 0.5%/patient-year (95% CI 0.2% to 0.8%/patient-year), and the redo-PVR rate was 1.9%/patient-year (95% CI 1.3% to 2.5%/patient-year). Data on RV volumes and ejection fractions were available from 5 studies (n = 141). The pooled mean difference in the indexed RV end-diastolic and end-systolic volume was -63 ml/m(2) (95% CI -55 to -72) and -37 ml/m(2) (95% CI -30 to -45), respectively. No significant changes in the pooled mean difference of the RV ejection fraction (95% CI -1% to 3%) or QRS duration (95% CI -10 to 1 ms) were observed. In conclusion, surgical PVR in patients after tetralogy of Fallot repair has been associated with low early and late mortality and significant decreases in RV volumes but no changes in the RV ejection fraction or QRS duration.