Predicting outcome of pulmonary valve replacement in adult tetralogy of Fallot patients

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.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

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.

Cardiovascular magnetic resonance normal values in children for biventricular wall thickness and mass

BACKGROUND

Pediatric patients are becoming increasingly referred for cardiovascular magnetic resonance (CMR). Measurement of ventricular wall thickness is typically part of the assessment and can be of diagnostic importance, e.g. in arterial hypertension. However, normal values for left ventricular (LV) and right ventricular (RV) wall thickness in pediatric patients are lacking. The aim of this study was to establish pediatric centile charts for segmental LV and RV myocardial thickness in a retrospective multicenter CMR study.

METHODS

CMR was performed in 161 healthy children and adolescents with an age range between 6 and 18 years from two centers in the UK and Germany as well as from a previously published CMR project of the German Competence Network for Congenital Heart Defects. LV myocardial thickness of 16 segments was measured on the short axis stack using the American Heart Association segmentation model. In addition, the thickness of the RV inferior and anterior free wall as well as biventricular mass was measured.

RESULTS

The mean age (standard deviation) of the subjects was 13.6 (2.9) years, 64 (39.7%) were female. Myocardial thickness of the basal septum (basal antero- and inferoseptal wall) was 5.2 (1.1) mm, and the basal lateral wall (basal antero- and inferolateral) measured 5.1 (1.2) mm. Mid-ventricular septum (antero- and inferoseptal wall) measured 5.5 (1.2) mm, and mid-ventricular lateral wall (antero- and inferolateral wall) was 4.7 (1.2) mm. Separate centile charts for boys and girls for all myocardial segments and myocardial mass were created because gender was significantly correlated with LV myocardial thickness (p < 0.001 at basal level, p = 0.001 at midventricular level and p = 0.005 at the apex) and biventricular mass (LV, p < 0.001; RV, p < 0.001).

CONCLUSION

We established CMR normal values of segmental myocardial thickness and biventricular mass in children and adolescents. Our data are of use for the detection of abnormal myocardial properties and can serve as a reference in future studies and clinical practice.

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.

When "Blue Babies" Grow Up: Complications After Surgical Repair of Tetralogy of Fallot

Tetralogy of Fallot (TOF) is a complex congenital cardiac defect. Surgical correction is well established as the treatment of choice and has resulted in a rapidly growing group of adults living with TOF. We describe potential complications of patients who have undergone TOF repair and were lost to follow-up. (Level of Difficulty: Intermediate.)

Preoperative Threshold for Normalizing Right Ventricular Volume After Transcatheter Closure of Adult Atrial Septal Defect

BACKGROUND

The latest guidelines recommend early intervention in adult atrial septal defect (ASD) patients with signs of right ventricular (RV) enlargement. However, the criteria of RV enlargement for optimal intervention remain unclear. We investigated the preoperative determinants for normalizing the RV volume after transcatheter closure of ASD in adults.Methods and Results:We retrospectively analyzed 52 ASD patients who underwent transcatheter closure. Cardiac magnetic resonance imaging (CMR) measured RV volume before and 1 year after the closure. The patients were divided into normalized (postoperative RV end-systolic volume index [RVESVI] <47 mL/m²and end-diastolic volume index [RVEDVI] <108 mL/m²) and non-normalized (postoperative RVESVI ≥47 mL/m²or RVEDVI ≥108 mL/m²) groups. Preoperative RVESVI was significantly smaller (72 mL/m²vs. 80 mL/m²) and RVEF was higher (56% vs. 51%) in the normalized group compared with the non-normalized group. Receiver-operating characteristic analysis for the normalization of postoperative RV volume showed that the preoperative threshold value of RVESVI was 75 mL/m². In addition, multivariate analysis showed that preoperative RVESVI was an independent predictor for normalization of RV volume.

CONCLUSIONS

Preoperative RVESVI is an independent predictor for normalization of RV volume at 1 year after transcatheter closure of ASD in adults. Early intervention before RVESVI reaches 75 mL/m²may confer optimal timing for normalizing RV volume.

Impact of right atrium dimension on adverse outcome after pulmonary valve replacement in repaired Tetralogy of Fallot patients

The hemodynamic impact of residual pulmonary regurgitation (PR) in repaired Tetralogy of Fallot (rTOF) has been well demonstrated. However, markers driving the decision making process to indicate the ideal timing of pulmonary valve replacement (PVR) are still uncertain. Furthermore, very few studies have included the right atrium (RA) dilatation as a preoperative risk factor for post-PVR clinical adverse outcome. The aim of this study was to investigate the impact of pre-PVR right atrial dilation on adverse outcomes in rTOF. We retrospectively reviewed from our CMR database all rTOF patients who underwent CMR study before and after PVR. Detailed clinical and surgical history were collected, in addition to imaging data. The composite primary and secondary post-PVR end points were also recorded. The study cohort consisted of 41 patients (mean age at PVR repair 27.4 ± 10 years). As expected, end-diastolic and end-systolic right ventricle (RV) volumes significantly decreased after PVR (p < 0.001). The RV reverse remodeling, defined by ΔRVEDVi and ΔRVESVi, was associated with both pre-PVR RVEDVi and RVESVi. The higher the pre-PVR RV volumes, more the RV reverse remodeling will be obtained post-surgery. Patients who experienced an adverse outcome were older at pre-PVR, they had a higher Nt-ProBNP, worse VO₂/kg/min, more significant tricuspid regurgitation and more dilated RA. The association with the RA dilatation persists and becomes even more significant if we exclude patients who had tricuspid repair beside RVOT surgical reconstruction. Besides RV volumes and function, RA dimensions may play a pivotal role in the decision making of TOF patients.

Percutaneous Pulmonary Valve Implantation: Current Status and Future Perspectives

Patients with congenital heart disease (CHD) with right ventricle outflow tract (RVOT) dysfunction need sequential pulmonary valve replacements throughout their life in the majority of cases. Since their introduction in 2000, the number of percutaneous pulmonary valve implantations (PPVI) has grown and reached over 10,000 procedures worldwide. Overall, PPVI has been proven safe and effective, but some anatomical variations can limit procedural success. This review discusses the current status and future perspectives of the procedure.

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.

Role of Cardiac Magnetic Resonance Imaging in Valvular Heart Disease: Diagnosis, Assessment, and Management

PURPOSE OF REVIEW

This article will review the current techniques in cardiac magnetic resonance imaging (CMR) for diagnosing and assessing primary valvular heart disease.

RECENT FINDINGS

The recent advancements in CMR have led to an increased role of this modality for qualifying and quantifying various native valve diseases. Phase-contrast velocity encoded imaging is a well-established technique that can be used to quantify aortic and pulmonic flow. This technique, combined with the improved ability for CMR to obtain accurate left and right ventricular volumetrics, has allowed for increased accuracy and reproducibility in assessing valvular dysfunction. Advancements in CMR technology also allows for improved spatial and temporal resolution imaging of various valves and their regurgitant or stenotic jets. Therefore, CMR can be a powerful tool in evaluation of native valvular heart disease. The role of CMR in assessing valvular heart disease is growing and being recognized in recent guidelines. CMR has the ability to assess valve morphology along with qualifying and quantifying valvular disease. In addition, the ability to obtain accurate volumetric measurements may improve more precise management strategies and may lead to improvements in mortality and morbidity.

Pulmonary valve replacement after repaired Tetralogy of Fallot

In this review article, we describe pulmonary valve replacement (PVR) late after repaired Tetralogy of Fallot (TOF). Since the introduction of surgical intervention for patients with TOF in 1945, surgical management of TOF has dramatically improved early survival with mortality rates, less than 2-3%. However, the majority of these patients continue to experience residual right ventricular outflow tract pathology, most commonly pulmonary valve regurgitation (PR). The patients are generally asymptomatic during childhood and adolescence and, however, are at risk for severe PR later which can result in exercise intolerance, heart failure, arrhythmias, and sudden death. While it has been shown that PVR improves symptoms and functional status in these patients, the optimal timing and indications for PVR after repaired TOF are still debated. This article reviews the current state of management for the patient with PR after repaired TOF.

Flow Energy Loss as a Predictive Parameter for Right Ventricular Deterioration Caused by Pulmonary Regurgitation After Tetralogy of Fallot Repair

The optimal timing for pulmonary valve replacement after Tetralogy of Fallot (TOF) repair remains controversial. In this study, we estimated the feasibility of using flow energy loss (FEL) to predict right ventricular (RV) deterioration due to pulmonary regurgitation after TOF repair. We examined RV outflow tract (RVOT) flow in nine patients who underwent TOF or double-outlet right ventricle repair in the intervention group (Group I) and compared them with three healthy children in the control group (Group C). We evaluated flow across the RVOT and pulmonary valve by vector flow mapping (VFM) on echocardiography and by phase contrast-magnetic resonance imaging (PC-MRI). Next, we calculated FEL and analyzed the relationship between FEL and clinical parameters of RV function. The mean FEL was significantly greater in Group I than in Group C (p = 0.002). Flow pattern and FEL were comparable by VFM and PC-MRI at the same phase 14.6 years after TOF repair. There was a significant positive correlation for the cardiothoracic ratio with both the mean FEL [correlation coefficient (r) = 0.78; p = 0.012] and the diastolic peak FEL (r = 0.75; p = 0.021) in Group I. There was also a significant positive correlation between the serial change in QRS duration with both the mean FEL (r = 0.82; p = 0.014) and the diastolic FEL (r = 0.70; p = 0.052) in Group I. FEL by VFM is an effective tool for evaluating ventricular deterioration caused by RV workload.

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.

Pulmonary Right Ventricular Resynchronization in Congenital Heart Disease

Background—

Electromechanical discoordination may contribute to long-term pulmonary right ventricular (RV) dysfunction in patients after surgery for congenital heart disease. We sought to evaluate changes in RV function after temporary RV cardiac resynchronization therapy.

Methods and Results—

Twenty-five patients aged median 12.0 years after repair of tetralogy of Fallot and similar lesions were studied echocardiographically (n=23) and by cardiac catheterization (n=5) after primary repair (n=4) or after surgical RV revalvulation for significant pulmonary regurgitation (n=21). Temporary RV cardiac resynchronization therapy was applied in the presence of complete right bundle branch block by atrial-synchronized RV free wall pacing in complete fusion with spontaneous ventricular depolarization using temporary electrodes. The q-RV interval at the RV free wall pacing site (mean 77.2% of baseline QRS duration) confirmed pacing from a late activated RV area. RV cardiac resynchronization therapy carried significant decrease in QRS duration ( P <0.001) along with elimination of the right bundle branch block QRS morphology, increase in RV filling time ( P =0.002), pulmonary artery velocity time integral ( P =0.006), and RV maximum +dP/dt ( P <0.001), and decrease in RV index of myocardial performance ( P =0.006). RV mechanical synchrony improved: septal-to-lateral RV mechanical delay decreased ( P <0.001) and signs of RV dyssynchrony pattern were significantly abolished. RV systolic stretch fraction reflecting the ratio of myocardial stretching and contraction during systole diminished ( P =0.001).

Conclusions—

In patients with congenital heart disease and right bundle branch block, RV cardiac resynchronization therapy carried multiple positive effects on RV mechanics, synchrony, and contraction efficiency.

Timing of Pulmonary Valve Replacement: How Much Can the Right Ventricle Dilate Before it Looses Its Remodeling Potential?

Congenital heart disease patients that develop secondary pulmonary regurgitation require a pulmonary valve replacement (PVR) in their follow-up. The indications for PVR in asymptomatic patients are debated. Most guidelines consider a RV end-diastolic volume (RVEDV) over 150 ml/m(2) as an indication for PVR. We analyzed clinical, echocardiographic and MRI variables of patients that underwent a surgical PVR between September 2006 and February 2013. The included patients were asymptomatic, without pulmonary stenosis and with both pre- and post-surgery MRI. Thirty-five patients (74.3 % males) were included. Mean age at PVR was 25.8 years (SD = 7.18), and weight was 64.5 Kg (SD = 12.03). The main diagnosis was tetralogy of Fallot (n = 28), pulmonary atresia (n = 2), primary pulmonary regurgitation (n = 2) and pulmonary regurgitation after percutaneous treatment (n = 2). The maximal RVEDV pre-PVR was 267 ml/m(2), and right ventricular end-systolic volume (RVESV) was 183 ml/m(2). RV size and function were established by MRI: Pre-PVR Post-PVR p RVEDV (ml/m(2)) 162 (SD = 39.1) 94 (SD = 23.6) <0.001 RVESV (ml/m(2)) 87 (SD = 28.9) 44 (SD = 15.7) <0.001 RVEF 44.8 % (SD = 8.17) 52 % (SD = 9.9) <0.001 Patients with a RVEDV under 170 ml/m(2) combined with a RVESV under 90 ml/m(2) had a favorable RV remodeling, defined as RVEDV under 110 ml/m(2) (sensitivity 87.5 %), RVESV under 55 ml/m(2) (sensitivity 100 %) and RVEF over 50 % (sensitivity 100 %). When deciding the optimal PVR timing in asymptomatic patients, both RVEDV and RVESV should be considered. Our results suggest that higher volumes than used in the clinical practice can achieve a good remodeling. Therefore, PVR could be performed later in the follow-up reducing the number of cardiac interventions.

Clinical utility of the plasma brain natriuretic peptide level in monitoring tetralogy of fallot patients over the long term after initial intracardiac repair: considerations for pulmonary valve replacement

Clinicians are currently encountering an increasing number of patients in the long-term period after tetralogy of Fallot (TOF) repair presenting with pulmonary valve regurgitation (PR) or right ventricular (RV) dysfunction. The purpose of this study was to evaluate the clinical utility of the plasma brain natriuretic peptide (BNP) level and consider surgical indications and timing of pulmonary valve replacement (PVR). We examined 33 patients (21 males, 12 females, mean age 14.5 ± 2.8 years) who underwent TOF repair at Kitasato University Hospital. All patients were evaluated using echocardiography and blood sampling. The mean age at the time of initial repair was 1.3 ± 0.7 years. The patients with moderate-severe PR exhibited significantly higher plasma BNP levels than the patients with trivial-mild PR (mean 37.5 ± 33.1 vs. 17.3 ± 6.6 pg/ml, p = 0.013). The mean plasma BNP level with cardiac symptoms was higher than that observed in the patients without any symptoms (71.4 ± 46.1 vs. 25.0 ± 14.0 pg/ml, p = 0.005). The mean BNP level was significantly decreased after PVR (71.3 ± 46.1-26.1 ± 13.2 pg/ml, p = 0.009), and the plasma BNP level was found to be positively correlated with the RV end-diastolic pressure (r = 0.851; p = 0.008). The optimal BNP cut-off value for considering PVR was 32.15 pg/ml (sensitivity, 85.7 %; specificity, 83.3 %). The plasma BNP level may become a useful diagnostic tool for considering the indications and optimal timing of PVR over the long term after TOF repair.

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.

Imaging of the right heart--CT and CMR

Right ventricular (RV) structure and function is of substantial importance in a broad variety of clinical conditions. Cardiac magnetic resonance (CMR) and computed tomography (CT) each provide three-dimensional RV imaging, high-resolution evaluation of RV structure/anatomy, and accurate functional assessment without geometric assumptions. This is of particular significance for the RV, where complex geometry compromises reliance on indices derived from two-dimensional (2D) imaging planes. CMR flow-based imaging can be applied to right-sided heart valves, enabling evaluation of hemodynamic and valvular dysfunction that may contribute to or result from RV dysfunction. Tissue characterization imaging by both CMR and CT provides valuable complementary assessment of the RV. Changes in myocardial tissue composition provide a mechanistic substrate for RV dysfunction and cardiac arrhythmias. This review provides an overview of RV imaging by both CMR and CT, with focus on assessment of RV structure/function, flow, and tissue characterization. Emerging evidence and established guidelines are discussed in the context of imaging contributions to diagnosis, prognostic risk stratification and disease management of clinical conditions that impact the right ventricle.

Surgical pulmonary valve insertion

Pulmonary valve replacement is being performed with increasing frequency in patients with various congenital heart diseases. Chronic pulmonary regurgitation after repair of tetralogy of Fallot is a typical situation that requires pulmonary valve replacement. Chronic pulmonary regurgitation after repair of tetralogy of Fallot can lead to right ventricular dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias, and sudden death. Although pulmonary valve replacement can lead to improvement in functional class and a substantial decrease or normalisation of right ventricular volumes, the optimal timing of pulmonary valve replacement in patients with chronic pulmonary regurgitation is still unknown. There are several options for surgical pulmonary valve replacement. However, no ideal pulmonary valve substitute exists currently and most of the surgically implanted pulmonary valves will eventually require re-replacement. This article will review options and timing of surgical pulmonary valve insertion in patients with chronic pulmonary regurgitation after repair of tetralogy of Fallot.

Surgical pulmonary valve insertion--when, how, and why

Relief of right ventricular outflow tract obstruction in tetralogy of Fallot or similar physiology often results in pulmonary regurgitation. The resultant chronic volume overload can lead to right ventricular dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias, and sudden death. Although pulmonary valve replacement can lead to improvement in functional class and a substantial decrease or normalisation of right ventricular volumes, the optimal timing of pulmonary valve replacement is not well defined. Benefits of pulmonary valve replacement have to be weighed against the risks of this procedure, including subsequent reoperation. This article will review the benefits and risks of pulmonary valve replacement, options for pulmonary valve substitute, and timing of pulmonary valve replacement in patients with chronic pulmonary regurgitation after relief of right ventricular outflow tract obstruction.

Surgical management of chronic pulmonary regurgitation after relief of right ventricular outflow tract obstruction

Relief of right ventricular (RV) outflow tract obstruction in tetralogy of Fallot or similar physiology often results in pulmonary regurgitation (PR). The resultant chronic volume overload can lead to RV dilatation, biventricular dysfunction, heart failure symptoms, arrhythmias and sudden death. Although pulmonary valve replacement (PVR) can lead to improvement in the functional class and a substantial decrease or normalization of RV volumes, the optimal timing of PVR is not well defined. Benefits of PVR have to be weighed against the risks of this procedure including subsequent reoperation. This article reviews the pathophysiology of chronic PR, evidence-based benefits and risks of PVR, options for valve substitute, and optimal timing of PVR in patients with chronic PR after relief of RV outflow tract obstruction.

Right ventricular regional wall curvedness and area strain in patients with repaired tetralogy of Fallot

A quantitative understanding of right ventricular (RV) remodeling in repaired tetralogy of Fallot (rTOF) is crucial for patient management. The objective of this study is to quantify the regional curvatures and area strain based on three-dimensional (3-D) reconstructions of the RV using cardiac magnetic resonance imaging (MRI). Fourteen (14) rTOF patients and nine (9) normal subjects underwent cardiac MRI scan. 3-D RV endocardial surface models were reconstructed from manually delineated contours and correspondence between end-diastole (ED) and end systole (ES) was determined. Regional curvedness (C) and surface area at ED and ES were calculated as well as the area strain. The RV shape and deformation in rTOF patients differed from normal subjects in several respects. Firstly, the curvedness at ED (mean for 13 segments, 0.030 ± 0.0076 vs. 0.029 ± 0.0065 mm(-1); P < 0.05) and ES (mean for 13 segments, 0.040 ± 0.012 vs. 0.034 ± 0.0072 mm(-1); P < 0.001) was decreased by chronic pulmonary regurgitation. Secondly, the surface area increased significantly at ED (mean for 13 segments, 982 ± 192 vs. 1,397 ± 387 mm(2); P < 0.001) and ES (mean for 13 segments, 576 ± 130 vs. 1,012 ± 302 mm(2); P < 0.001). In particular, rTOF patients had significantly larger surface area than that in normal subjects in the free wall but not for the septal wall. Thirdly, area strain was significantly decreased (mean for 13 segments, 56 ± 6 vs. 34 ± 7%; P < 0.0001) in rTOF patients. Fourthly, there were increases in surface area at ED (5,726 ± 969 vs. 6,605 ± 1,122 mm(2); P < 0.05) and ES (4,280 ± 758 vs. 5,569 ± 1,112 mm(2); P < 0.01) and decrease in area strain (29 ± 8 vs. 18 ± 8%; P < 0.001) for RV outflow tract. These findings suggest significant geometric and strain differences between rTOF and normal subjects that may help guide therapeutic treatment.

The role of cardiovascular magnetic resonance in adults with congenital heart disease

The comprehensive coverage and versatility of cardiovascular magnetic resonance (CMR), providing functional as well as anatomical information, make it an important facility in a center specializing in the care of adults with congenital heart disease. Imaging specialists using CMR to investigate acquired heart disease should also be able to recognize and evaluate previously unsuspected congenital malformations. Conditions that may present or be picked up during imaging in adulthood include atrial septal defect, anomalously connected pulmonary veins, double-chambered right ventricle, congenitally corrected transposition of the great arteries, aortic coarctation, and patent arterial duct. To realize its full potential and to avoid pitfalls, CMR of adults with congenital heart disease requires specific training and experience. Appropriate pathophysiological understanding is needed to evaluate cardiovascular function after surgery for tetralogy of Fallot, after transposition of the great arteries, and after Fontan operations. For these and other more complex cases, CMR should ideally be undertaken by specialists committed to long-term collaboration with the clinicians and surgeons managing the patients in a tertiary referral center.

Imaging congenital heart disease in adults

Transthoracic echocardiography is the first-line modality for cardiovascular imaging in adults with congenital heart disease (ACHD). The windows of access that are possible with transthoracic echocardiography are, however, rarely adequate for all regions of interest. The choice of further imaging depends on the clinical questions that remain to be addressed. The strengths of MRI include comprehensive access and coverage, providing imaging of all parts of the right ventricle, the pulmonary arteries, pulmonary veins and aorta. Cine images and velocity maps are acquired in specifically aligned planes, with stacks of cines or dynamic contrast angiography providing more comprehensive coverage. Tissues can be characterised if necessary, and MRI provides relatively accurate measurements of biventricular function and volume flow. These parameters are important in the assessment and follow-up of adults after repairs for tetralogy of Fallot or transposition of the great arteries and after Fontan operations. The superior spatial resolution and rapid acquisition of CT are invaluable in selected situations, including the visualisation of anomalous coronary or aortopulmonary collateral arteries, the assessment of luminal patency after stenting and imaging in patients with pacemakers. Ionising radiation is, however, a concern in younger patients who may need repeated investigation. Adults with relatively complex conditions should ideally be imaged in a specialist ACHD centre, where dedicated echocardiographic and cardiovascular MRI services are a necessary facility. General radiologists should be aware of the nature and pathophysiology of congenital heart disease, and should be alert for previously undiagnosed cases presenting in adulthood, including cases of atrial septal defect, aortic coarctation, patent ductus arteriosus, double-chambered right ventricle and congenitally corrected transposition.

The impact of pulmonary regurgitation on right ventricular regional myocardial function: an echocardiographic study in adults after total repair of tetralogy of Fallot

BACKGROUND

Early results of tetralogy of Fallot (TOF) surgical repair are excellent, but patients are at risk for long-term complications. The purpose of the study was to determine to what extent ultrasonic tissue indices can be helpful in assessing the degree of pulmonary regurgitation (PR).

METHODS

Fifty adults (26 men, 24 women; mean age, 34.4 years) who had undergone TOF correction were studied.

RESULTS

Compared with normal controls, patients had decreased tricuspid annular plane systolic excursion (20.66 vs 26.79 mm, P < .05). In patients with TOF, maximal strain was reduced in all right ventricular free wall and interventricular septal segments. In patients with previous palliative shunts, lower maximal strain for RV basal segment was observed compared with subjects with no palliative surgery (-18.22% vs -22.27%, P < .05). Maximal systolic and early diastolic strain and strain rate values were significantly higher in patients with PR widths ≥ 3 mm compared with patients with PR widths < 3 mm.

CONCLUSIONS

Adults after TOF repair have decreased regional deformation of the right ventricle and intraventricular septum. Prior palliative treatment reduces the indices of right ventricular regional deformation. PR severity can be described by the extent of right ventricular regional deformation.

[MRI for therapy control in patients with tetralogy of Fallot]

With prevalences ranging from 0.26 to 0.8‰ of all live births tetralogy of Fallot (TOF) is the most common congenital heart disease with primary cyanosis. Due to improvements in surgical techniques, nearly all patients can nowadays expect to reach adulthood. After surgical repair, pulmonary regurgitation (PR) occurs in almost every child and is an important contributing factor in long-term morbidity and mortality. Cardiac magnetic resonance imaging is well established for functional assessment and flow measurements and is an ideal tool for serial post-surgical follow-up examinations, as it is non-invasive and does not expose patients to ionizing radiation. The timing of pulmonary valve replacement is crucial as right ventricular (RV) volumes have only proven to normalize when preoperative end-diastolic volumes are <170 ml/m(2) and end-systolic volumes are <85 ml/m(2). After surgical repair up to 15% of patients have residual or recurrent pulmonary artery stenosis. Distal pulmonary branch stenosis can aggravate PR and lead to right heart failure due to combined pressure and volume overload. Therefore, it has to be diagnosed in time and treated by angioplasty with or without stenting.

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.

Randomized trial of pulmonary valve replacement with and without right ventricular remodeling surgery

BACKGROUND

Although pulmonary valve replacement (PVR) is effective in reducing right ventricular (RV) volume overload in patients with chronic pulmonary regurgitation, persistent RV dysfunction and subsequent adverse clinical outcomes have been reported. This trial was conducted to investigate whether the addition of surgical RV remodeling with exclusion of scar tissue to PVR would result in improved RV function and laboratory and clinical parameters, as compared with PVR alone.

METHODS AND RESULTS

Between February 2004 and October 2008, 64 patients who underwent RV outflow tract procedures in early childhood had more than or equal to moderate pulmonary regurgitation, and fulfilled defined criteria for PVR were randomly assigned to undergo either PVR alone (n=34) or PVR with surgical RV remodeling (n=30). No significant difference was observed in the primary outcome (change in RV ejection fraction, -2±7% in the PVR alone group and -1±7% in the PVR with RV remodeling group; P=0.38) or in any of the secondary outcomes at 6-month postoperative follow-up. Multivariable analysis of the entire cohort identified preoperative RV end-systolic volume index <90 mL/m(2) and QRS duration <140 ms to be associated with optimal postoperative outcome (normal RV size and function), and RV ejection fraction <45% and QRS duration ≥160 ms to be associated with suboptimal postoperative outcome (RV dilatation and dysfunction).

CONCLUSIONS

The addition of surgical remodeling of the RV to PVR in patients with chronic pulmonary regurgitation did not result in a measurable early benefit. Referral to PVR based on QRS duration, RV end-systolic volume, or RV ejection fraction may be beneficial. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00112320.

Imaging the right ventricle--current state of the art

The right ventricle has long been the 'forgotten ventricle', as it is difficult to image owing to its complex morphology, its thin wall with coarse trabeculations, and its anterior position within the chest. Developments in cardiac magnetic resonance imaging (CMR) and echocardiography have provided new insights into right ventricular (RV) structure and function. RV performance seems to be an important determinant of clinical status and long-term outcome in patients with pulmonary hypertension, cardiomyopathies, and, especially, in patients with congenital heart disease. A variety of different parameters can be measured to assess RV function, but a lot of uncertainty remains on how to assess RV performance in daily clinical practice and which measurements to use in clinical decision-making. CMR is currently considered the reference technique for RV volumetry and calculation of ejection fraction. Various echocardiographic techniques can provide reliable information on RV dimensions and RV systolic and diastolic function that can be used in clinical follow-up. The introduction of newer echocardiographic techniques, such as three-dimensional echocardiography, tissue Doppler ultrasonography, and ultrasound strain imaging, challenge the leading role of CMR in RV functional assessment, but further validation and accumulation of data are required before these techniques can play a key part in clinical decision-making.